osmo-msc/tests/msc_vlr/msc_vlr_test_call.err

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large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DLMGCP MGCP client: using endpoint domain '@mgw'
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
===== test_call_mo
- Total time passed: 0.000000 s
- Location Update request causes a GSUP Send Auth Info request to HLR
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_LOC_UPD_REQUEST
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: LOCATION UPDATING REQUEST: MI=IMSI-901700000010650 LU-type=NORMAL
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: USIM: old LAI: 901-70-23
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + mm_rx_loc_upd_req: now used by 2 (rx_from_ms,mm_rx_loc_upd_req)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + lu: now used by 3 (rx_from_ms,mm_rx_loc_upd_req,lu)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Allocated
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: rev=R99 net=UTRAN Auth+Ciph
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
DREF VLR subscr unknown + _lu_fsm_associate_vsub: now used by 1 (_lu_fsm_associate_vsub)
DVLR set IMSI on subscriber; IMSI=901700000010650 id=901700000010650
DVLR New subscr, IMSI: 901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 + active-conn: now used by 2 (_lu_fsm_associate_vsub,active-conn)
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DREF VLR subscr IMSI-901700000010650 - _lu_fsm_associate_vsub: now used by 1 (active-conn)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1_pre()
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST: 08010809710000000156f02801020a0101
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_NEEDS_AUTH_WAIT_AI
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - mm_rx_loc_upd_req: now used by 2 (rx_from_ms,lu)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
lu_result_sent == 0
- from HLR, rx _SEND_AUTH_INFO_RESULT; VLR sends Auth Req to MS
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: 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
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: Received Event VLR_AUTH_E_HLR_SAI_ACK
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) Received 5 auth tuples
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=0 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:UTRAN-Iu:LU: tuple use_count=1 key_seq=0 auth_types=0x3 and...
- ...rand=39fa2f4e3d523d8619a73b4f65c3e14d
- ...autn=8704f5ba55f30000d2ee44b22c8ea919
- ...expecting res=e229c19e791f2e41
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: vlr_gsupc_read_cb() returns 0
auth_request_sent == 1
lu_result_sent == 0
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = e229c19e791f2e41)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) AUTH on UTRAN received RES: e229c19e791f2e41 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Received Event VLR_ULA_E_AUTH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: vlr_loc_upd_post_auth()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=27497388b6cb044648f396aa155b95ef
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: state_chg to VLR_ULA_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
security_mode_ctrl_sent == 1
lu_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts and sends GSUP LU Req to HLR
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: Received Event VLR_ULA_E_CIPH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_post_ciph()
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_node_4()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Allocated
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000000156f02801020a0101
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
gsup_tx_confirmed == 1
lu_result_sent == 0
- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000000156f00804032443f20a0101
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR IMSI:901700000010650 has MSISDN:42342
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
lu_result_sent == 0
- HLR also sends GSUP _UPDATE_LOCATION_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Allocated
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: lu_compl_vlr_new_tmsi()
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_WAIT_TMSI_CNF
- sending LU Accept for IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU, with TMSI 0x03020100
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Deallocated
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
lu_result_sent == 1
- a LU Accept with a new TMSI was sent, waiting for TMSI Realloc Compl
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
llist_count(&msub_list) == 1
msc_a_is_accepted() == false
- MS sends TMSI Realloc Complete
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_TMSI_REALL_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_TMSI_REALL_COMPL
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: TMSI Reallocation Completed
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_NEW_TMSI_ACK
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: Received Event LU_COMPL_VLR_E_NEW_TMSI_ACK
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + attached: now used by 2 (active-conn,attached)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: state_chg to LU_COMPL_VLR_S_DONE
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Deallocated
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - lu: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (active-conn,attached)
iu_release_sent == 1
- LU was successful, and the conn has already been closed
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + lu_utran_tmsi: now used by 2 (attached,lu_utran_tmsi)
vsub != NULL == 1
strcmp(vsub->imsi, IMSI) == 0
LAC == 23
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - lu_utran_tmsi: now used by 1 (attached)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- after a while, a new conn sends a CM Service Request. VLR responds with Auth Req, 2nd auth vector
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_CM_SERV_REQ
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_CM_SERV_REQ
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Rx CM SERVICE REQUEST cm_service_type=MO-Call
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: + cm_service_cc: now used by 2 (rx_from_ms,cm_service_cc)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Allocated
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: rev=R99 net=UTRAN Auth+Ciph
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Received Event PR_ARQ_E_START
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + proc_arq_vlr_fn_init: now used by 2 (attached,proc_arq_vlr_fn_init)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + active-conn: now used by 3 (attached,proc_arq_vlr_fn_init,active-conn)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: proc_arq_vlr_fn_post_imsi()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: state_chg to PR_ARQ_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: is child of Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=1 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ: tuple use_count=1 key_seq=1 auth_types=0x3 and...
- ...rand=c187a53a5e6b9d573cac7c74451fd46d
- ...autn=1843a645b98d00005b2d666af46c45d9
- ...expecting res=7db47cf7f81e4dc7
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - proc_arq_vlr_fn_init: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
cm_service_result_sent == 0
auth_request_sent == 1
- needs auth, not yet accepted
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
msc_a_is_accepted() == false
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = 7db47cf7f81e4dc7)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH on UTRAN received RES: 7db47cf7f81e4dc7 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Removing from parent Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Received Event PR_ARQ_E_AUTH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: _proc_arq_vlr_node2()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=1159ec926a50e98c034a6b7d7c9f418d
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: state_chg to PR_ARQ_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
security_mode_ctrl_sent == 1
cm_service_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts; above Ciphering is an implicit CM Service Accept
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: Received Event PR_ARQ_E_CIPH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_ciph()
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_vlr()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_pres()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_trace()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_imei()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: proc_arq_fsm_done(PASSED)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: state_chg to PR_ARQ_S_DONE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Process Access Request result: PASSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
cm_service_result_sent == 0
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- a call is initiated
- SETUP gets forwarded to MNCC
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_SETUP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Dispatching 04.08 message: CC GSM48_MT_CC_SETUP
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + CC: now used by 3 (attached,active-conn,CC)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x80000001 tid-8) New transaction
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + cc: now used by 3 (cm_service_cc,rx_from_ms,cc)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cm_service_cc: now used by 2 (rx_from_ms,cc)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx SETUP in state NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting guard timer with 180 seconds
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state NULL -> INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) SETUP to 123
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) tx MNCC_SETUP_IND
MSC --> MNCC: callref 0x80000001: MNCC_SETUP_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- MNCC replies with MNCC_RTP_CREATE, causing MGW endpoint CRCX to RAN
MSC <-- MNCC: callref 0x80000001: MNCC_RTP_CREATE
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_RTP_CREATE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Starting call assignment
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Allocated
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: is child of msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
MGW <--CRCX to RTP_TO_RAN-- MSC: callref=0x80000001
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
- MGW acknowledges the CRCX, triggering Assignment
MGW --CRCX OK to RTP_TO_RAN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_RAN: 10.23.23.1:23 (osmux=no:-2)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: ASSIGNMENT_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Assignment succeeds, triggering CRCX to CN
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: ASSIGNMENT_COMPLETE
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: setting remote addr to :0
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Not committing: no MGW endpoint CI set up
MGW <--CRCX to RTP_TO_CN-- MSC: callref=0x80000001
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_CN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
- CN RTP address is available, trigger MNCC_RTP_CREATE
MGW --CRCX OK to RTP_TO_CN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_CN: 10.23.23.1:23 (osmux=no:-2)
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) tx MNCC_RTP_CREATE
MSC --> MNCC: callref 0x80000001: MNCC_RTP_CREATE
- MNCC says that's fine
MSC <-- MNCC: callref 0x80000001: MNCC_CALL_PROC_REQ
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_CALL_PROC_REQ
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending guard timer
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting guard timer with 180 seconds
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_CALL_PROC_REQ in state INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state INITIATED -> MO_CALL_PROC
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_CALL_PROC
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_CALL_PROC: 8302
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Assignment for this trans already started earlier
- Total time passed: 1.000023 s
- The other call leg got established (not shown here), MNCC tells us so
MSC <-- MNCC: callref 0x80000001: MNCC_ALERT_REQ
DMNCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_ALERT_REQ
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending guard timer
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting guard timer with 180 seconds
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_ALERT_REQ in state MO_CALL_PROC
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state MO_CALL_PROC -> CALL_DELIVERED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_ALERTING
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_ALERTING: 8301
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
MSC <-- MNCC: callref 0x80000001: MNCC_SETUP_RSP
DMNCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_SETUP_RSP
DCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending guard timer
DCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting guard timer with 180 seconds
DCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_SETUP_RSP in state CALL_DELIVERED
DCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting timer T313 with 30 seconds
DCC trans(CC:CALL_DELIVERED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state CALL_DELIVERED -> CONNECT_IND
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_CONNECT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_CONNECT: 8307
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Total time passed: 2.000046 s
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_CONNECT_ACK
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_CONNECT_ACK
DCC trans(CC:CONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx CONNECT_ACK in state CONNECT_IND
DCC trans(CC:CONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending timer T313
DCC trans(CC:CONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state CONNECT_IND -> ACTIVE
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending guard timer
DMNCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) tx MNCC_SETUP_COMPL_IND
MSC --> MNCC: callref 0x80000001: MNCC_SETUP_COMPL_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- RTP stream goes ahead, not shown here.
- Total time passed: 125.000091 s
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- Call ends
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_DISCONNECT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_DISCONNECT
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx DISCONNECT in state ACTIVE
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state ACTIVE -> DISCONNECT_IND
DMNCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) tx MNCC_DISC_IND
MSC --> MNCC: callref 0x80000001: MNCC_DISC_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
MSC <-- MNCC: callref 0x80000001: MNCC_REL_REQ
DMNCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_REL_REQ
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting guard timer with 180 seconds
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx MNCC_REL_REQ in state DISCONNECT_IND
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) starting timer T308 with 10 seconds
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) new state DISCONNECT_IND -> RELEASE_REQ
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 832d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_RELEASE_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_RELEASE_COMPL
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) rx RELEASE_COMPL in state RELEASE_REQ
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) stopping pending timer T308
DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000001 tid-8) tx MNCC_REL_CNF
MSC --> MNCC: callref 0x80000001: MNCC_REL_CNF
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) Freeing transaction
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) new state RELEASE_REQ -> NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) stopping pending guard timer
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cc: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (attached,active-conn,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: state_chg to RELEASING
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_CN:no-CI){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_CN:no-CI){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_CN:no-CI){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483649:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_EV_CALL_LEG_TERM
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Deallocated, including all deferred deallocations
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (attached,active-conn)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DVLR freeing VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 (max total use count was 4)
===== test_call_mo: SUCCESS
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
===== test_call_mt
- Total time passed: 0.000000 s
- Location Update request causes a GSUP Send Auth Info request to HLR
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_LOC_UPD_REQUEST
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: LOCATION UPDATING REQUEST: MI=IMSI-901700000010650 LU-type=NORMAL
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: USIM: old LAI: 901-70-23
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + mm_rx_loc_upd_req: now used by 2 (rx_from_ms,mm_rx_loc_upd_req)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + lu: now used by 3 (rx_from_ms,mm_rx_loc_upd_req,lu)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Allocated
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: rev=R99 net=UTRAN Auth+Ciph
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
DREF VLR subscr unknown + _lu_fsm_associate_vsub: now used by 1 (_lu_fsm_associate_vsub)
DVLR set IMSI on subscriber; IMSI=901700000010650 id=901700000010650
DVLR New subscr, IMSI: 901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 + active-conn: now used by 2 (_lu_fsm_associate_vsub,active-conn)
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DREF VLR subscr IMSI-901700000010650 - _lu_fsm_associate_vsub: now used by 1 (active-conn)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1_pre()
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST: 08010809710000000156f02801020a0101
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_NEEDS_AUTH_WAIT_AI
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - mm_rx_loc_upd_req: now used by 2 (rx_from_ms,lu)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
lu_result_sent == 0
- from HLR, rx _SEND_AUTH_INFO_RESULT; VLR sends Auth Req to MS
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: 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
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: Received Event VLR_AUTH_E_HLR_SAI_ACK
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) Received 5 auth tuples
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=0 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:UTRAN-Iu:LU: tuple use_count=1 key_seq=0 auth_types=0x3 and...
- ...rand=39fa2f4e3d523d8619a73b4f65c3e14d
- ...autn=8704f5ba55f30000d2ee44b22c8ea919
- ...expecting res=e229c19e791f2e41
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: vlr_gsupc_read_cb() returns 0
auth_request_sent == 1
lu_result_sent == 0
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = e229c19e791f2e41)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) AUTH on UTRAN received RES: e229c19e791f2e41 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Received Event VLR_ULA_E_AUTH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: vlr_loc_upd_post_auth()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=27497388b6cb044648f396aa155b95ef
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: state_chg to VLR_ULA_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
security_mode_ctrl_sent == 1
lu_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts and sends GSUP LU Req to HLR
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: Received Event VLR_ULA_E_CIPH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_post_ciph()
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_node_4()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Allocated
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000000156f02801020a0101
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
gsup_tx_confirmed == 1
lu_result_sent == 0
- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000000156f00804032443f20a0101
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR IMSI:901700000010650 has MSISDN:42342
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
lu_result_sent == 0
- HLR also sends GSUP _UPDATE_LOCATION_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Allocated
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: lu_compl_vlr_new_tmsi()
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_WAIT_TMSI_CNF
- sending LU Accept for IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU, with TMSI 0x03020100
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Deallocated
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
lu_result_sent == 1
- a LU Accept with a new TMSI was sent, waiting for TMSI Realloc Compl
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
llist_count(&msub_list) == 1
msc_a_is_accepted() == false
- MS sends TMSI Realloc Complete
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_TMSI_REALL_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_TMSI_REALL_COMPL
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: TMSI Reallocation Completed
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_NEW_TMSI_ACK
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: Received Event LU_COMPL_VLR_E_NEW_TMSI_ACK
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + attached: now used by 2 (active-conn,attached)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: state_chg to LU_COMPL_VLR_S_DONE
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Deallocated
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - lu: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (active-conn,attached)
iu_release_sent == 1
- LU was successful, and the conn has already been closed
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + lu_utran_tmsi: now used by 2 (attached,lu_utran_tmsi)
vsub != NULL == 1
strcmp(vsub->imsi, IMSI) == 0
LAC == 23
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - lu_utran_tmsi: now used by 1 (attached)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- after a while, MNCC asks us to setup a call, causing Paging
MSC <-- MNCC: callref 0x423: MNCC_SETUP_REQ
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + mncc_tx_to_gsm_cc: now used by 2 (attached,mncc_tx_to_gsm_cc)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + CC: now used by 3 (attached,mncc_tx_to_gsm_cc,CC)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) New transaction
DMNCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) rx MNCC_SETUP_REQ
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Starting paging
paging request (CALL_CONVERSATIONAL) to IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 on UTRAN-Iu
strcmp(paging_expecting_imsi, vsub->imsi) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + Paging: now used by 4 (attached,mncc_tx_to_gsm_cc,CC,Paging)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - mncc_tx_to_gsm_cc: now used by 3 (attached,CC,Paging)
paging_sent == 1
- MS replies with Paging Response, and VLR sends Auth Request
MSC <--UTRAN-Iu-- MS: GSM48_MT_RR_PAG_RESP
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: RR GSM48_MT_RR_PAG_RESP
DRR msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: Rx PAGING RESPONSE IMSI-901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: + paging-response: now used by 2 (rx_from_ms,paging-response)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: Allocated
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: rev=R99 net=UTRAN Auth+Ciph
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: Received Event PR_ARQ_E_START
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + proc_arq_vlr_fn_init: now used by 4 (attached,CC,Paging,proc_arq_vlr_fn_init)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + active-conn: now used by 5 (attached,CC,Paging,proc_arq_vlr_fn_init,active-conn)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: proc_arq_vlr_fn_post_imsi()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: state_chg to PR_ARQ_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: is child of Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=1 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP: tuple use_count=1 key_seq=1 auth_types=0x3 and...
- ...rand=c187a53a5e6b9d573cac7c74451fd46d
- ...autn=1843a645b98d00005b2d666af46c45d9
- ...expecting res=7db47cf7f81e4dc7
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - proc_arq_vlr_fn_init: now used by 4 (attached,CC,Paging,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (paging-response)
auth_request_sent == 1
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (paging-response,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = 7db47cf7f81e4dc7)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH on UTRAN received RES: 7db47cf7f81e4dc7 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Removing from parent Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: Received Event PR_ARQ_E_AUTH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: _proc_arq_vlr_node2()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=1159ec926a50e98c034a6b7d7c9f418d
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: state_chg to PR_ARQ_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (paging-response)
security_mode_ctrl_sent == 1
- MS sends SecurityModeControl acceptance, VLR accepts, sends CC Setup
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: Received Event PR_ARQ_E_CIPH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_ciph()
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_vlr()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_pres()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_trace()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_imei()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: proc_arq_fsm_done(PASSED)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: state_chg to PR_ARQ_S_DONE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Process Access Request result: PASSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Paging Response action (success)
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Removing Paging Request
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) Paging succeeded
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: + cc: now used by 2 (paging-response,cc)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T303 with 30 seconds
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state NULL -> CALL_PRESENT
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_SETUP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_SETUP: 0305
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - Paging: now used by 3 (attached,CC,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - paging-response: now used by 1 (cc)
- MS confirms call, we create a RAN-side RTP and forward MNCC_CALL_CONF_IND
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_CALL_CONF
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_CALL_CONF
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx CALL_CONF in state CALL_PRESENT
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T303
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T310 with 30 seconds
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CALL_PRESENT -> MO_TERM_CALL_CONF
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Starting call assignment
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Allocated
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: is child of msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
MGW <--CRCX to RTP_TO_RAN-- MSC: callref=0x423
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_CALL_CONF_IND
MSC --> MNCC: callref 0x423: MNCC_CALL_CONF_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- MNCC sends MNCC_RTP_CREATE
MSC <-- MNCC: callref 0x423: MNCC_RTP_CREATE
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_RTP_CREATE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Assignment for this trans already started earlier
- MGW acknowledges the CRCX to RAN, triggering Assignment
MGW --CRCX OK to RTP_TO_RAN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_RAN: 10.23.23.1:23 (osmux=no:-2)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: ASSIGNMENT_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Assignment completes, triggering CRCX to CN
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: ASSIGNMENT_COMPLETE
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: setting remote addr to :0
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Not committing: no MGW endpoint CI set up
MGW <--CRCX to RTP_TO_CN-- MSC: callref=0x423
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
- When the CN side RTP address is known, send MNCC_RTP_CREATE
MGW --CRCX OK to RTP_TO_CN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_CN: 10.23.23.1:23 (osmux=no:-2)
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_RTP_CREATE
MSC --> MNCC: callref 0x423: MNCC_RTP_CREATE
- Total time passed: 1.000023 s
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_ALERTING
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_ALERTING
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx ALERTING in state MO_TERM_CALL_CONF
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T310
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T301 with 180 seconds
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state MO_TERM_CALL_CONF -> CALL_RECEIVED
DMNCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_ALERT_IND
MSC --> MNCC: callref 0x423: MNCC_ALERT_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- Total time passed: 2.000046 s
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_CONNECT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_CONNECT
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx CONNECT in state CALL_RECEIVED
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T301
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CALL_RECEIVED -> CONNECT_REQUEST
DMNCC trans(CC:CONNECT_REQUEST IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_SETUP_CNF
MSC --> MNCC: callref 0x423: MNCC_SETUP_CNF
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
MSC <-- MNCC: callref 0x423: MNCC_SETUP_COMPL_REQ
DMNCC trans(CC:CONNECT_REQUEST IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_SETUP_COMPL_REQ
DCC trans(CC:CONNECT_REQUEST IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting guard timer with 180 seconds
DCC trans(CC:CONNECT_REQUEST IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_SETUP_COMPL_REQ in state CONNECT_REQUEST
DCC trans(CC:CONNECT_REQUEST IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CONNECT_REQUEST -> ACTIVE
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending guard timer
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_CONNECT_ACK
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_CONNECT_ACK: 030f
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- RTP stream goes ahead, not shown here.
- Total time passed: 125.000091 s
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- Call ends
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_DISCONNECT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_DISCONNECT
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx DISCONNECT in state ACTIVE
DCC trans(CC:ACTIVE IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state ACTIVE -> DISCONNECT_IND
DMNCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_DISC_IND
MSC --> MNCC: callref 0x423: MNCC_DISC_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
MSC <-- MNCC: callref 0x423: MNCC_REL_REQ
DMNCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_REL_REQ
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting guard timer with 180 seconds
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_REL_REQ in state DISCONNECT_IND
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T308 with 10 seconds
DCC trans(CC:DISCONNECT_IND IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state DISCONNECT_IND -> RELEASE_REQ
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 032d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_RELEASE_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_RELEASE_COMPL
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx RELEASE_COMPL in state RELEASE_REQ
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T308
DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_REL_CNF
MSC --> MNCC: callref 0x423: MNCC_REL_CNF
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x0 tid-0) Freeing transaction
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x0 tid-0) new state RELEASE_REQ -> NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x0 tid-0) stopping pending guard timer
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - cc: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (attached,active-conn,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: state_chg to RELEASING
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Received Event MSC_EV_CALL_LEG_TERM
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Deallocated, including all deferred deallocations
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (attached,active-conn)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: max total use count was 2
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DVLR freeing VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 (max total use count was 5)
===== test_call_mt: SUCCESS
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
===== test_call_mt2
- Total time passed: 0.000000 s
- Location Update request causes a GSUP Send Auth Info request to HLR
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_LOC_UPD_REQUEST
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: LOCATION UPDATING REQUEST: MI=IMSI-901700000010650 LU-type=NORMAL
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: USIM: old LAI: 901-70-23
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + mm_rx_loc_upd_req: now used by 2 (rx_from_ms,mm_rx_loc_upd_req)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + lu: now used by 3 (rx_from_ms,mm_rx_loc_upd_req,lu)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Allocated
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: rev=R99 net=UTRAN Auth+Ciph
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
DREF VLR subscr unknown + _lu_fsm_associate_vsub: now used by 1 (_lu_fsm_associate_vsub)
DVLR set IMSI on subscriber; IMSI=901700000010650 id=901700000010650
DVLR New subscr, IMSI: 901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 + active-conn: now used by 2 (_lu_fsm_associate_vsub,active-conn)
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DREF VLR subscr IMSI-901700000010650 - _lu_fsm_associate_vsub: now used by 1 (active-conn)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1_pre()
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST: 08010809710000000156f02801020a0101
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_NEEDS_AUTH_WAIT_AI
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - mm_rx_loc_upd_req: now used by 2 (rx_from_ms,lu)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
lu_result_sent == 0
- from HLR, rx _SEND_AUTH_INFO_RESULT; VLR sends Auth Req to MS
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: 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
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: Received Event VLR_AUTH_E_HLR_SAI_ACK
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) Received 5 auth tuples
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=0 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:UTRAN-Iu:LU: tuple use_count=1 key_seq=0 auth_types=0x3 and...
- ...rand=39fa2f4e3d523d8619a73b4f65c3e14d
- ...autn=8704f5ba55f30000d2ee44b22c8ea919
- ...expecting res=e229c19e791f2e41
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: vlr_gsupc_read_cb() returns 0
auth_request_sent == 1
lu_result_sent == 0
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = e229c19e791f2e41)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) AUTH on UTRAN received RES: e229c19e791f2e41 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Received Event VLR_ULA_E_AUTH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: vlr_loc_upd_post_auth()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=27497388b6cb044648f396aa155b95ef
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: state_chg to VLR_ULA_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
security_mode_ctrl_sent == 1
lu_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts and sends GSUP LU Req to HLR
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: Received Event VLR_ULA_E_CIPH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_post_ciph()
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_node_4()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Allocated
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000000156f02801020a0101
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
gsup_tx_confirmed == 1
lu_result_sent == 0
- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000000156f00804032443f20a0101
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR IMSI:901700000010650 has MSISDN:42342
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
lu_result_sent == 0
- HLR also sends GSUP _UPDATE_LOCATION_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Allocated
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: lu_compl_vlr_new_tmsi()
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_WAIT_TMSI_CNF
- sending LU Accept for IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU, with TMSI 0x03020100
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Deallocated
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
lu_result_sent == 1
- a LU Accept with a new TMSI was sent, waiting for TMSI Realloc Compl
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
llist_count(&msub_list) == 1
msc_a_is_accepted() == false
- MS sends TMSI Realloc Complete
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_TMSI_REALL_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_TMSI_REALL_COMPL
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: TMSI Reallocation Completed
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_NEW_TMSI_ACK
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: Received Event LU_COMPL_VLR_E_NEW_TMSI_ACK
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + attached: now used by 2 (active-conn,attached)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: state_chg to LU_COMPL_VLR_S_DONE
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Deallocated
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - lu: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (active-conn,attached)
iu_release_sent == 1
- LU was successful, and the conn has already been closed
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + lu_utran_tmsi: now used by 2 (attached,lu_utran_tmsi)
vsub != NULL == 1
strcmp(vsub->imsi, IMSI) == 0
LAC == 23
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - lu_utran_tmsi: now used by 1 (attached)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- after a while, MNCC asks us to setup a call, causing Paging
MSC <-- MNCC: callref 0x423: MNCC_SETUP_REQ
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + mncc_tx_to_gsm_cc: now used by 2 (attached,mncc_tx_to_gsm_cc)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + CC: now used by 3 (attached,mncc_tx_to_gsm_cc,CC)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) New transaction
DMNCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) rx MNCC_SETUP_REQ
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Starting paging
paging request (CALL_CONVERSATIONAL) to IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 on UTRAN-Iu
strcmp(paging_expecting_imsi, vsub->imsi) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + Paging: now used by 4 (attached,mncc_tx_to_gsm_cc,CC,Paging)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - mncc_tx_to_gsm_cc: now used by 3 (attached,CC,Paging)
paging_sent == 1
- MS replies with Paging Response, and VLR sends Auth Request
MSC <--UTRAN-Iu-- MS: GSM48_MT_RR_PAG_RESP
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: RR GSM48_MT_RR_PAG_RESP
DRR msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: Rx PAGING RESPONSE IMSI-901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: + paging-response: now used by 2 (rx_from_ms,paging-response)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: Allocated
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: rev=R99 net=UTRAN Auth+Ciph
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: Received Event PR_ARQ_E_START
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + proc_arq_vlr_fn_init: now used by 4 (attached,CC,Paging,proc_arq_vlr_fn_init)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + active-conn: now used by 5 (attached,CC,Paging,proc_arq_vlr_fn_init,active-conn)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: proc_arq_vlr_fn_post_imsi()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_INIT}: state_chg to PR_ARQ_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: is child of Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=1 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP: tuple use_count=1 key_seq=1 auth_types=0x3 and...
- ...rand=c187a53a5e6b9d573cac7c74451fd46d
- ...autn=1843a645b98d00005b2d666af46c45d9
- ...expecting res=7db47cf7f81e4dc7
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - proc_arq_vlr_fn_init: now used by 4 (attached,CC,Paging,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (paging-response)
auth_request_sent == 1
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (paging-response,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = 7db47cf7f81e4dc7)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH on UTRAN received RES: 7db47cf7f81e4dc7 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Removing from parent Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: Received Event PR_ARQ_E_AUTH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: _proc_arq_vlr_node2()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=1159ec926a50e98c034a6b7d7c9f418d
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_AUTH}: state_chg to PR_ARQ_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (paging-response)
security_mode_ctrl_sent == 1
- MS sends SecurityModeControl acceptance, VLR accepts, sends CC Setup
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: Received Event PR_ARQ_E_CIPH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_ciph()
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_vlr()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_pres()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_trace()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_imei()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: proc_arq_fsm_done(PASSED)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_WAIT_CIPH}: state_chg to PR_ARQ_S_DONE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Process Access Request result: PASSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Paging Response action (success)
DPAG Paging: IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 for MNCC: establish call: Removing Paging Request
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x423 tid-255) Paging succeeded
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: + cc: now used by 2 (paging-response,cc)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T303 with 30 seconds
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state NULL -> CALL_PRESENT
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_SETUP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_SETUP: 0305
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - Paging: now used by 3 (attached,CC,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - paging-response: now used by 1 (cc)
- MS confirms call, we create a RAN-side RTP and forward MNCC_CALL_CONF_IND
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_CALL_CONF
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_CALL_CONF
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx CALL_CONF in state CALL_PRESENT
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T303
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T310 with 30 seconds
DCC trans(CC:CALL_PRESENT IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CALL_PRESENT -> MO_TERM_CALL_CONF
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Starting call assignment
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Allocated
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: is child of msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
MGW <--CRCX to RTP_TO_RAN-- MSC: callref=0x423
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_CALL_CONF_IND
MSC --> MNCC: callref 0x423: MNCC_CALL_CONF_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- MNCC sends MNCC_RTP_CREATE
MSC <-- MNCC: callref 0x423: MNCC_RTP_CREATE
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx MNCC_RTP_CREATE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Assignment for this trans already started earlier
- MGW acknowledges the CRCX to RAN, triggering Assignment
MGW --CRCX OK to RTP_TO_RAN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_RAN: 10.23.23.1:23 (osmux=no:-2)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: ASSIGNMENT_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Assignment completes, triggering CRCX to CN
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: ASSIGNMENT_COMPLETE
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: setting remote addr to :0
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Not committing: no MGW endpoint CI set up
MGW <--CRCX to RTP_TO_CN-- MSC: callref=0x423
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
- When the CN side RTP address is known, send MNCC_RTP_CREATE
MGW --CRCX OK to RTP_TO_CN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_CN: 10.23.23.1:23 (osmux=no:-2)
DMNCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_RTP_CREATE
MSC --> MNCC: callref 0x423: MNCC_RTP_CREATE
- Total time passed: 1.000023 s
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_ALERTING
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_ALERTING
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) rx ALERTING in state MO_TERM_CALL_CONF
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T310
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T301 with 180 seconds
DCC trans(CC:MO_TERM_CALL_CONF IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state MO_TERM_CALL_CONF -> CALL_RECEIVED
DMNCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_ALERT_IND
MSC --> MNCC: callref 0x423: MNCC_ALERT_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- Total time passed: 16.000046 s
- The call failed, the BSC sends a BSSMAP Clear Request
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Received Event MSC_A_EV_CN_CLOSE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Releasing: msc_a use is 1 (cc)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 4 (attached,CC,active-conn,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 5 (attached,CC,active-conn,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 4 (attached,CC,active-conn,msc_a_fsm_releasing_onenter)
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) Freeing transaction
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T301
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T308 with 10 seconds
DCC trans(CC:CALL_RECEIVED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state CALL_RECEIVED -> RELEASE_REQ
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 032d0802e1af
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) tx MNCC_REL_CNF
MSC --> MNCC: callref 0x423: MNCC_REL_CNF
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) stopping pending timer T308
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state RELEASE_REQ -> NULL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: - cc: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){ESTABLISHING}: state_chg to RELEASING
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_CN:no-CI){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP:trans-0:call-1059:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Received Event MSC_EV_CALL_LEG_TERM
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){RELEASING}: Deallocated, including all deferred deallocations
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (attached,active-conn)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){PR_ARQ_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: max total use count was 2
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
- Total time passed: 31.000069 s
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR freeing VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 (max total use count was 5)
===== test_call_mt2: SUCCESS
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
===== test_call_mo_to_unknown
- Total time passed: 0.000000 s
- Location Update request causes a GSUP Send Auth Info request to HLR
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_LOC_UPD_REQUEST
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: LOCATION UPDATING REQUEST: MI=IMSI-901700000010650 LU-type=NORMAL
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: USIM: old LAI: 901-70-23
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + mm_rx_loc_upd_req: now used by 2 (rx_from_ms,mm_rx_loc_upd_req)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + lu: now used by 3 (rx_from_ms,mm_rx_loc_upd_req,lu)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Allocated
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: rev=R99 net=UTRAN Auth+Ciph
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
DREF VLR subscr unknown + _lu_fsm_associate_vsub: now used by 1 (_lu_fsm_associate_vsub)
DVLR set IMSI on subscriber; IMSI=901700000010650 id=901700000010650
DVLR New subscr, IMSI: 901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 + active-conn: now used by 2 (_lu_fsm_associate_vsub,active-conn)
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DREF VLR subscr IMSI-901700000010650 - _lu_fsm_associate_vsub: now used by 1 (active-conn)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1_pre()
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST: 08010809710000000156f02801020a0101
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_NEEDS_AUTH_WAIT_AI
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - mm_rx_loc_upd_req: now used by 2 (rx_from_ms,lu)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
lu_result_sent == 0
- from HLR, rx _SEND_AUTH_INFO_RESULT; VLR sends Auth Req to MS
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: 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
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: Received Event VLR_AUTH_E_HLR_SAI_ACK
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) Received 5 auth tuples
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=0 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:UTRAN-Iu:LU: tuple use_count=1 key_seq=0 auth_types=0x3 and...
- ...rand=39fa2f4e3d523d8619a73b4f65c3e14d
- ...autn=8704f5ba55f30000d2ee44b22c8ea919
- ...expecting res=e229c19e791f2e41
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: vlr_gsupc_read_cb() returns 0
auth_request_sent == 1
lu_result_sent == 0
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = e229c19e791f2e41)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) AUTH on UTRAN received RES: e229c19e791f2e41 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Received Event VLR_ULA_E_AUTH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: vlr_loc_upd_post_auth()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=27497388b6cb044648f396aa155b95ef
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: state_chg to VLR_ULA_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
security_mode_ctrl_sent == 1
lu_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts and sends GSUP LU Req to HLR
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: Received Event VLR_ULA_E_CIPH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_post_ciph()
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_node_4()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Allocated
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000000156f02801020a0101
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
gsup_tx_confirmed == 1
lu_result_sent == 0
- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000000156f00804032443f20a0101
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR IMSI:901700000010650 has MSISDN:42342
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
lu_result_sent == 0
- HLR also sends GSUP _UPDATE_LOCATION_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Allocated
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: lu_compl_vlr_new_tmsi()
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_WAIT_TMSI_CNF
- sending LU Accept for IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU, with TMSI 0x03020100
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Deallocated
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
lu_result_sent == 1
- a LU Accept with a new TMSI was sent, waiting for TMSI Realloc Compl
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
llist_count(&msub_list) == 1
msc_a_is_accepted() == false
- MS sends TMSI Realloc Complete
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_TMSI_REALL_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_TMSI_REALL_COMPL
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: TMSI Reallocation Completed
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_NEW_TMSI_ACK
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: Received Event LU_COMPL_VLR_E_NEW_TMSI_ACK
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + attached: now used by 2 (active-conn,attached)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: state_chg to LU_COMPL_VLR_S_DONE
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Deallocated
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - lu: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (active-conn,attached)
iu_release_sent == 1
- LU was successful, and the conn has already been closed
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + lu_utran_tmsi: now used by 2 (attached,lu_utran_tmsi)
vsub != NULL == 1
strcmp(vsub->imsi, IMSI) == 0
LAC == 23
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - lu_utran_tmsi: now used by 1 (attached)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- after a while, a new conn sends a CM Service Request. VLR responds with Auth Req, 2nd auth vector
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_CM_SERV_REQ
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_CM_SERV_REQ
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Rx CM SERVICE REQUEST cm_service_type=MO-Call
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: + cm_service_cc: now used by 2 (rx_from_ms,cm_service_cc)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Allocated
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: rev=R99 net=UTRAN Auth+Ciph
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Received Event PR_ARQ_E_START
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + proc_arq_vlr_fn_init: now used by 2 (attached,proc_arq_vlr_fn_init)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + active-conn: now used by 3 (attached,proc_arq_vlr_fn_init,active-conn)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: proc_arq_vlr_fn_post_imsi()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: state_chg to PR_ARQ_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: is child of Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=1 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ: tuple use_count=1 key_seq=1 auth_types=0x3 and...
- ...rand=c187a53a5e6b9d573cac7c74451fd46d
- ...autn=1843a645b98d00005b2d666af46c45d9
- ...expecting res=7db47cf7f81e4dc7
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - proc_arq_vlr_fn_init: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
cm_service_result_sent == 0
auth_request_sent == 1
- needs auth, not yet accepted
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
msc_a_is_accepted() == false
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = 7db47cf7f81e4dc7)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH on UTRAN received RES: 7db47cf7f81e4dc7 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Removing from parent Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Received Event PR_ARQ_E_AUTH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: _proc_arq_vlr_node2()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=1159ec926a50e98c034a6b7d7c9f418d
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: state_chg to PR_ARQ_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
security_mode_ctrl_sent == 1
cm_service_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts; above Ciphering is an implicit CM Service Accept
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: Received Event PR_ARQ_E_CIPH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_ciph()
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_vlr()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_pres()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_trace()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_imei()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: proc_arq_fsm_done(PASSED)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: state_chg to PR_ARQ_S_DONE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Process Access Request result: PASSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
cm_service_result_sent == 0
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- a call is initiated
- SETUP gets forwarded to MNCC
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_SETUP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Dispatching 04.08 message: CC GSM48_MT_CC_SETUP
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + CC: now used by 3 (attached,active-conn,CC)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x80000002 tid-8) New transaction
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + cc: now used by 3 (cm_service_cc,rx_from_ms,cc)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cm_service_cc: now used by 2 (rx_from_ms,cc)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx SETUP in state NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) starting guard timer with 180 seconds
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) new state NULL -> INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) SETUP to 123
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) tx MNCC_SETUP_IND
MSC --> MNCC: callref 0x80000002: MNCC_SETUP_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- MNCC replies with MNCC_RTP_CREATE, causing MGW endpoint CRCX to RAN
MSC <-- MNCC: callref 0x80000002: MNCC_RTP_CREATE
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx MNCC_RTP_CREATE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Starting call assignment
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Allocated
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: is child of msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
MGW <--CRCX to RTP_TO_RAN-- MSC: callref=0x80000002
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
- MGW acknowledges the CRCX, triggering Assignment
MGW --CRCX OK to RTP_TO_RAN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_RAN: 10.23.23.1:23 (osmux=no:-2)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: ASSIGNMENT_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Assignment succeeds, triggering CRCX to CN
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: ASSIGNMENT_COMPLETE
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: setting remote addr to :0
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Not committing: no MGW endpoint CI set up
MGW <--CRCX to RTP_TO_CN-- MSC: callref=0x80000002
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_CN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
- CN RTP address is available, trigger MNCC_RTP_CREATE
MGW --CRCX OK to RTP_TO_CN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_CN: 10.23.23.1:23 (osmux=no:-2)
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) tx MNCC_RTP_CREATE
MSC --> MNCC: callref 0x80000002: MNCC_RTP_CREATE
- MNCC says that's fine
MSC <-- MNCC: callref 0x80000002: MNCC_CALL_PROC_REQ
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx MNCC_CALL_PROC_REQ
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) stopping pending guard timer
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) starting guard timer with 180 seconds
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx MNCC_CALL_PROC_REQ in state INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) new state INITIATED -> MO_CALL_PROC
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_CALL_PROC
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_CALL_PROC: 8302
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Assignment for this trans already started earlier
- But the other side's MSISDN could not be resolved, MNCC tells us to cancel
MSC <-- MNCC: callref 0x80000002: MNCC_REL_REQ
DMNCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx MNCC_REL_REQ
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) stopping pending guard timer
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) starting guard timer with 180 seconds
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx MNCC_REL_REQ in state MO_CALL_PROC
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) starting timer T308 with 10 seconds
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) new state MO_CALL_PROC -> RELEASE_REQ
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 832d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Total time passed: 10.000023 s
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) starting timer T308 with 10 seconds
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 832d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_RELEASE_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + rx_from_ms: now used by 2 (cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Dispatching 04.08 message: CC GSM48_MT_CC_RELEASE_COMPL
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) rx RELEASE_COMPL in state RELEASE_REQ
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) stopping pending timer T308
DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000002 tid-8) tx MNCC_REL_CNF
MSC --> MNCC: callref 0x80000002: MNCC_REL_CNF
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) Freeing transaction
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) new state RELEASE_REQ -> NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x0 tid-8) stopping pending guard timer
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cc: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (attached,active-conn,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: state_chg to RELEASING
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_CN:no-CI){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_CN:no-CI){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_CN:no-CI){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483650:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_EV_CALL_LEG_TERM
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Deallocated, including all deferred deallocations
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (attached,active-conn)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DVLR freeing VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 (max total use count was 4)
===== test_call_mo_to_unknown: SUCCESS
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
===== test_call_mo_to_unknown_timeout
- Total time passed: 0.000000 s
- Location Update request causes a GSUP Send Auth Info request to HLR
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_LOC_UPD_REQUEST
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: LOCATION UPDATING REQUEST: MI=IMSI-901700000010650 LU-type=NORMAL
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: USIM: old LAI: 901-70-23
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + mm_rx_loc_upd_req: now used by 2 (rx_from_ms,mm_rx_loc_upd_req)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: + lu: now used by 3 (rx_from_ms,mm_rx_loc_upd_req,lu)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Allocated
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: rev=R99 net=UTRAN Auth+Ciph
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: Received Event VLR_ULA_E_UPDATE_LA
DREF VLR subscr unknown + _lu_fsm_associate_vsub: now used by 1 (_lu_fsm_associate_vsub)
DVLR set IMSI on subscriber; IMSI=901700000010650 id=901700000010650
DVLR New subscr, IMSI: 901700000010650
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 + active-conn: now used by 2 (_lu_fsm_associate_vsub,active-conn)
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DREF VLR subscr IMSI-901700000010650 - _lu_fsm_associate_vsub: now used by 1 (active-conn)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1_pre()
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: vlr_loc_upd_node1()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_IDLE}: state_chg to VLR_ULA_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST: 08010809710000000156f02801020a0101
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_NEEDS_AUTH_WAIT_AI
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - mm_rx_loc_upd_req: now used by 2 (rx_from_ms,lu)
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
lu_result_sent == 0
- from HLR, rx _SEND_AUTH_INFO_RESULT; VLR sends Auth Req to MS
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: 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
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: Received Event VLR_AUTH_E_HLR_SAI_ACK
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) Received 5 auth tuples
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_NEEDS_AUTH_WAIT_AI}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=0 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:UTRAN-Iu:LU: tuple use_count=1 key_seq=0 auth_types=0x3 and...
- ...rand=39fa2f4e3d523d8619a73b4f65c3e14d
- ...autn=8704f5ba55f30000d2ee44b22c8ea919
- ...expecting res=e229c19e791f2e41
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT: vlr_gsupc_read_cb() returns 0
auth_request_sent == 1
lu_result_sent == 0
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = e229c19e791f2e41)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650) AUTH on UTRAN received RES: e229c19e791f2e41 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Received Event VLR_ULA_E_AUTH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: vlr_loc_upd_post_auth()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=27497388b6cb044648f396aa155b95ef
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_AUTH}: state_chg to VLR_ULA_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:UTRAN-Iu:LU){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (lu)
security_mode_ctrl_sent == 1
lu_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts and sends GSUP LU Req to HLR
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: Received Event VLR_ULA_E_CIPH_RES
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_post_ciph()
DMSC msc_a(IMSI-901700000010650:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: vlr_loc_upd_node_4()
DVLR vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU){VLR_ULA_S_WAIT_CIPH}: state_chg to VLR_ULA_S_WAIT_HLR_UPD
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Allocated
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:UTRAN-Iu:LU)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: Received Event UPD_HLR_VLR_E_START
GSUP --> HLR: OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST: 04010809710000000156f02801020a0101
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_INIT}: state_chg to UPD_HLR_VLR_S_WAIT_FOR_DATA
gsup_tx_confirmed == 1
lu_result_sent == 0
- HLR sends _INSERT_DATA_REQUEST, VLR responds with _INSERT_DATA_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: 10010809710000000156f00804032443f20a0101
DREF VLR subscr IMSI-901700000010650 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR IMSI:901700000010650 has MSISDN:42342
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
GSUP --> HLR: OSMO_GSUP_MSGT_INSERT_DATA_RESULT: 12010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_INSERT_DATA_REQUEST: vlr_gsupc_read_cb() returns 0
lu_result_sent == 0
- HLR also sends GSUP _UPDATE_LOCATION_RESULT
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: 06010809710000000156f00a0101
DREF VLR subscr IMSI-901700000010650:MSISDN-42342 + vlr_gsup_rx: now used by 2 (active-conn,vlr_gsup_rx)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_HLR_LU_RES
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: Received Event UPD_HLR_VLR_E_UPD_LOC_ACK
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_WAIT_FOR_DATA}: state_chg to UPD_HLR_VLR_S_DONE
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: Received Event VLR_ULA_E_UPD_HLR_COMPL
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){VLR_ULA_S_WAIT_HLR_UPD}: state_chg to VLR_ULA_S_WAIT_LU_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Allocated
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: is child of vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: Received Event LU_COMPL_VLR_E_START
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_INIT}: state_chg to LU_COMPL_VLR_S_WAIT_SUB_PRES
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: Received Event LU_COMPL_VLR_E_SUB_PRES_COMPL
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: lu_compl_vlr_new_tmsi()
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_SUB_PRES}: state_chg to LU_COMPL_VLR_S_WAIT_TMSI_CNF
- sending LU Accept for IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU, with TMSI 0x03020100
DVLR upd_hlr_vlr_fsm(IMSI-901700000010650:UTRAN-Iu:LU){UPD_HLR_VLR_S_DONE}: Deallocated
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100 - vlr_gsup_rx: now used by 1 (active-conn)
<-- GSUP rx OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT: vlr_gsupc_read_cb() returns 0
lu_result_sent == 1
- a LU Accept with a new TMSI was sent, waiting for TMSI Realloc Compl
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
llist_count(&msub_list) == 1
msc_a_is_accepted() == false
- MS sends TMSI Realloc Complete
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_TMSI_REALL_COMPL
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (lu,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_TMSI_REALL_COMPL
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: TMSI Reallocation Completed
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSInew-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_NEW_TMSI_ACK
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: Received Event LU_COMPL_VLR_E_NEW_TMSI_ACK
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) VLR: update for IMSI=901700000010650 (MSISDN=42342)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + attached: now used by 2 (active-conn,attached)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_WAIT_TMSI_CNF}: state_chg to LU_COMPL_VLR_S_DONE
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: Received Event VLR_ULA_E_LU_COMPL_SUCCESS
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Removing from parent vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR lu_compl_vlr_fsm(IMSI-901700000010650:MSISDN-42342:UTRAN-Iu:LU){LU_COMPL_VLR_S_DONE}: Deallocated
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_WAIT_LU_COMPL}: state_chg to VLR_ULA_S_DONE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - lu: now used by 1 (rx_from_ms)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: - rx_from_ms: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (active-conn,attached,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (active-conn,attached,msc_a_fsm_releasing_onenter)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (active-conn,attached)
iu_release_sent == 1
- LU was successful, and the conn has already been closed
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: fsm_lu_cleanup called with cause OSMO_FSM_TERM_PARENT
DVLR vlr_lu_fsm(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){VLR_ULA_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:LU){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + lu_utran_tmsi: now used by 2 (attached,lu_utran_tmsi)
vsub != NULL == 1
strcmp(vsub->imsi, IMSI) == 0
LAC == 23
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - lu_utran_tmsi: now used by 1 (attached)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- after a while, a new conn sends a CM Service Request. VLR responds with Auth Req, 2nd auth vector
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_CM_SERV_REQ
new conn
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msub_fsm{active}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: Allocated
DMSC msc_a{MSC_A_ST_VALIDATE_L3}: is child of msub_fsm
DMSC msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_VALIDATE_L3
DMSC dummy_msc_i{0}: Allocated
DMSC dummy_msc_i{0}: is child of msub_fsm
DREF msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: + rx_from_ms: now used by 1 (rx_from_ms)
DIUCS msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: RAN decode: COMPL_L3
DRLL msc_a(unknown:UTRAN-Iu:NONE){MSC_A_ST_VALIDATE_L3}: Dispatching 04.08 message: MM GSM48_MT_MM_CM_SERV_REQ
DMM msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Rx CM SERVICE REQUEST cm_service_type=MO-Call
DREF msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: + cm_service_cc: now used by 2 (rx_from_ms,cm_service_cc)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Allocated
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: is child of msc_a(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: rev=R99 net=UTRAN Auth+Ciph
DVLR Process_Access_Request_VLR(IMSI-901700000010650:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: Received Event PR_ARQ_E_START
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + proc_arq_vlr_fn_init: now used by 2 (attached,proc_arq_vlr_fn_init)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + active-conn: now used by 3 (attached,proc_arq_vlr_fn_init,active-conn)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: Received Event MSC_A_EV_COMPLETE_LAYER_3_OK
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_VALIDATE_L3}: state_chg to MSC_A_ST_AUTH_CIPH
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: proc_arq_vlr_fn_post_imsi()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_INIT}: state_chg to PR_ARQ_S_WAIT_AUTH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Allocated
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: is child of Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: Received Event VLR_AUTH_E_START
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_NEEDS_AUTH}: state_chg to VLR_SUB_AS_WAIT_RESP
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: got auth tuple: use_count=1 key_seq=1 -- will use UMTS AKA (is_r99=yes, at->vec.auth_types=0x3)
- sending UMTS Auth Request for IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ: tuple use_count=1 key_seq=1 auth_types=0x3 and...
- ...rand=c187a53a5e6b9d573cac7c74451fd46d
- ...autn=1843a645b98d00005b2d666af46c45d9
- ...expecting res=7db47cf7f81e4dc7
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - proc_arq_vlr_fn_init: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
cm_service_result_sent == 0
auth_request_sent == 1
- needs auth, not yet accepted
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
msc_a_is_accepted() == false
- MS sends Authen Response, VLR accepts and sends SecurityModeControl
MSC <--UTRAN-Iu-- MS: GSM48_MT_MM_AUTH_RESP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Dispatching 04.08 message: MM GSM48_MT_MM_AUTH_RESP
DMM msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: MM UMTS AUTHENTICATION RESPONSE (res = 7db47cf7f81e4dc7)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Received Event VLR_AUTH_E_MS_AUTH_RESP
refactor log ctx for vlr_subscr and ran_conn ran_conn_get_conn_id(): instead of a talloc allocated string, return a static buffer in ran_conn_get_conn_id(). So far this function had no callers. Refactor ran_conn_update_id() API: during early L3-Complete, when no subscriber is associated yet, update the FSM Id by the MI type seen in the L3 Complete message: ran_conn_update_id_from_mi(). Later on set the vsub and re-update. Call vlr.ops->subscr_update when the TMSI is updated, so that log context includes the TMSI from then on. Enrich context for vlr_subscr_name and ran_conn fi name. Include all available information in vlr_subscr_name(); instead of either IMSI or MSISDN or TMSI, print all of them when present. Instead of a short log, rather have more valuable context. A context info would now look like: Process_Access_Request_VLR(IMSI-901700000014706:MSISDN-2023:TMSI-0x08BDE4EC:GERAN-A-3:PAGING_RESP) It does get quite long, but ensures easy correlation of any BSSAP / IuCS messages with log output, especially if multiple subscribers are busy at the same time. Print TMSI and TMSInew in uppercase hexadecimal, which is the typical representation in the telecom world. When showing the RAN conn id GERAN_A-00000017 becomes GERAN-A-23 - We usually write the conn_id in decimal. - Leading zeros are clutter and might suggest hexadecimal format. - 'GERAN-A' and 'UTRAN-Iu' are the strings defined by osmo_rat_type_name(). Depends: I7798c3ef983c2e333b2b9cbffef6f366f370bd81 (libosmocore) Depends: Ica25919758ef6cba8348da199b0ae7e0ba628798 (libosmocore) Change-Id: I66a68ce2eb8957a35855a3743d91a86299900834
2019-01-03 01:32:14 +00:00
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH on UTRAN received RES: 7db47cf7f81e4dc7 (8 bytes)
DVLR SUBSCR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) AUTH established UMTS security context
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: Authentication terminating with result PASSED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_WAIT_RESP}: state_chg to VLR_SUB_AS_AUTHENTICATED
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Removing from parent Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Received Event PR_ARQ_E_AUTH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: _proc_arq_vlr_node2()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: Set Ciphering Mode
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: CIPHER_MODE_COMMAND on UTRAN-Iu
- sending SecurityModeControl: ik=1159ec926a50e98c034a6b7d7c9f418d
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_AUTH}: state_chg to PR_ARQ_S_WAIT_CIPH
DVLR VLR_Authenticate(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){VLR_SUB_AS_AUTHENTICATED}: Deallocated
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: - rx_from_ms: now used by 1 (cm_service_cc)
security_mode_ctrl_sent == 1
cm_service_result_sent == 0
- MS sends SecurityModeControl acceptance, VLR accepts; above Ciphering is an implicit CM Service Accept
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN decode: CIPHER_MODE_COMPLETE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: Received Event PR_ARQ_E_CIPH_RES
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_ciph()
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: RAN encode: COMMON_ID on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_node2_post_vlr()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_pres()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_trace()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: _proc_arq_vlr_post_imei()
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: proc_arq_fsm_done(PASSED)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_WAIT_CIPH}: state_chg to PR_ARQ_S_DONE
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Process Access Request result: PASSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: Received Event MSC_A_EV_AUTHENTICATED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTH_CIPH}: state_chg to MSC_A_ST_AUTHENTICATED
cm_service_result_sent == 0
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
- a call is initiated
- SETUP gets forwarded to MNCC
MSC <--UTRAN-Iu-- MS: GSM48_MT_CC_SETUP
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: + rx_from_ms: now used by 2 (cm_service_cc,rx_from_ms)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: RAN decode: DTAP
DRLL msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Dispatching 04.08 message: CC GSM48_MT_CC_SETUP
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + CC: now used by 3 (attached,active-conn,CC)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 callref-0x80000003 tid-8) New transaction
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: + cc: now used by 3 (cm_service_cc,rx_from_ms,cc)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cm_service_cc: now used by 2 (rx_from_ms,cc)
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx SETUP in state NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) starting guard timer with 180 seconds
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) new state NULL -> INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) SETUP to 123
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) tx MNCC_SETUP_IND
MSC --> MNCC: callref 0x80000003: MNCC_SETUP_IND
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - rx_from_ms: now used by 1 (cc)
- MNCC replies with MNCC_RTP_CREATE, causing MGW endpoint CRCX to RAN
MSC <-- MNCC: callref 0x80000003: MNCC_RTP_CREATE
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx MNCC_RTP_CREATE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Starting call assignment
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Allocated
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: is child of msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
MGW <--CRCX to RTP_TO_RAN-- MSC: callref=0x80000003
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
- MGW acknowledges the CRCX, triggering Assignment
MGW --CRCX OK to RTP_TO_RAN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_RAN: 10.23.23.1:23 (osmux=no:-2)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: ASSIGNMENT_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Assignment succeeds, triggering CRCX to CN
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN decode: ASSIGNMENT_COMPLETE
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: setting remote addr to :0
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Not committing: no MGW endpoint CI set up
MGW <--CRCX to RTP_TO_CN-- MSC: callref=0x80000003
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: Allocated
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){UNINITIALIZED}: is child of call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_CN:no-CI){UNINITIALIZED}: setting codec to AMR/8000/1
- CN RTP address is available, trigger MNCC_RTP_CREATE
MGW --CRCX OK to RTP_TO_CN--> MSC
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: Received Event CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_EV_CALL_LEG_RTP_LOCAL_ADDR_AVAILABLE
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: MGW endpoint's RTP address available for the CI RTP_TO_CN: 10.23.23.1:23 (osmux=no:-2)
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) tx MNCC_RTP_CREATE
MSC --> MNCC: callref 0x80000003: MNCC_RTP_CREATE
- MNCC says that's fine
MSC <-- MNCC: callref 0x80000003: MNCC_CALL_PROC_REQ
DMNCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx MNCC_CALL_PROC_REQ
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) stopping pending guard timer
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) starting guard timer with 180 seconds
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx MNCC_CALL_PROC_REQ in state INITIATED
DCC trans(CC:INITIATED IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) new state INITIATED -> MO_CALL_PROC
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_CALL_PROC
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_CALL_PROC: 8302
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Assignment for this trans already started earlier
- But the other side's MSISDN could not be resolved, MNCC tells us to cancel
MSC <-- MNCC: callref 0x80000003: MNCC_REL_REQ
DMNCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx MNCC_REL_REQ
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) stopping pending guard timer
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) starting guard timer with 180 seconds
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) rx MNCC_REL_REQ in state MO_CALL_PROC
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) starting timer T308 with 10 seconds
DCC trans(CC:MO_CALL_PROC IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) new state MO_CALL_PROC -> RELEASE_REQ
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 832d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- Despite our repeated CC Release Requests, the MS does not respond anymore
- Total time passed: 10.000023 s
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) starting timer T308 with 10 seconds
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_RELEASE
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
- DTAP --UTRAN-Iu--> MS: GSM48_MT_CC_RELEASE: 832d
- DTAP matches expected message
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
- The CC Release times out and we still properly clear the conn
- Total time passed: 20.000046 s
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) Freeing transaction
DMNCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) tx MNCC_REL_CNF
MSC --> MNCC: callref 0x80000003: MNCC_REL_CNF
DCC trans(CC:RELEASE_REQ IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) new state RELEASE_REQ -> NULL
DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ callref-0x80000003 tid-8) stopping pending guard timer
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - CC: now used by 2 (attached,active-conn)
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: - cc: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_COMMUNICATING}: state_chg to MSC_A_ST_RELEASING
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Releasing: msc_a use is 0 (-)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + msc_a_fsm_releasing_onenter: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 + vlr_subscr_cancel_attach_fsm: now used by 4 (attached,active-conn,msc_a_fsm_releasing_onenter,vlr_subscr_cancel_attach_fsm)
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - vlr_subscr_cancel_attach_fsm: now used by 3 (attached,active-conn,msc_a_fsm_releasing_onenter)
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){ESTABLISHING}: state_chg to RELEASING
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_CN:no-CI){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_CN:no-CI){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_CN:no-CI){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Removing from parent call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DCC rtp_stream(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ:trans-8:call-2147483651:RTP_TO_RAN:no-CI:local-10-23-23-1-23){UNINITIALIZED}: Deferring: will deallocate with call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_EV_CALL_LEG_TERM
DCC call_leg(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){RELEASING}: Deallocated, including all deferred deallocations
large refactoring: support inter-BSC and inter-MSC Handover 3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles: - MSC-A is responsible for managing subscribers, - MSC-I is the gateway to the RAN. - MSC-T is a second transitory gateway to another RAN during Handover. After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while the original MSC-A retains the responsibility of subscriber management. MSC-T exists in this patch but is not yet used, since Handover is only prepared for, not yet implemented. Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC roles. Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications: - all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc instance, - messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface (GSUP), - no call routing between MSC-A and -I via MNCC necessary. This is the largest code bomb I have submitted, ever. Out of principle, I apologize to everyone trying to read this as a whole. Unfortunately, I see no sense in trying to split this patch into smaller bits. It would be a huge amount of work to introduce these changes in separate chunks, especially if each should in turn be useful and pass all test suites. So, unfortunately, we are stuck with this code bomb. The following are some details and rationale for this rather huge refactoring: * separate MSC subscriber management from ran_conn struct ran_conn is reduced from the pivotal subscriber management entity it has been so far to a mere storage for an SCCP connection ID and an MSC subscriber reference. The new pivotal subscriber management entity is struct msc_a -- struct msub lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however use msc_a, since MSC-A is where all the interesting stuff happens. Before handover, msc_i is an FSM implementation that encodes to the local ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM implementation that instead forwards via/from GSUP. Same goes for the msc_a struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the msc_a->fi is an FSM implementation that merely forwards via/from GSUP. * New SCCP implementation for RAN access To be able to forward BSSAP and RANAP messages via the GSUP interface, the individual message layers need to be cleanly separated. The IuCS implementation used until now (iu_client from libosmo-ranap) did not provide this level of separation, and needed a complete rewrite. It was trivial to implement this in such a way that both BSSAP and RANAP can be handled by the same SCCP code, hence the new SCCP-RAN layer also replaces BSSAP handling. sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN connections. A set of callback functions provides implementation specific details. * RAN Abstraction (BSSAP vs. RANAP) The common SCCP implementation did set the theme for the remaining refactoring: make all other MSC code paths entirely RAN-implementation-agnostic. ran_infra.c provides data structures that list RAN implementation specifics, from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra pointer hence allows complete abstraction of RAN implementations: - managing connected RAN peers (BSC, RNC) in ran_peer.c, - classifying and de-/encoding RAN PDUs, - recording connected LACs and cell IDs and sending out Paging requests to matching RAN peers. * RAN RESET now also for RANAP ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide proper RESET handling, which it so far duly ignores. (TODO) * RAN de-/encoding abstraction The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP implementations transparently, but also to be able to optionally handle RAN on distinct levels. Before Handover, all RAN messages are handled by the MSC-A role. However, after an inter-MSC Handover, a standalone MSC-I will need to decode RAN PDUs, at least in order to manage Assignment of RTP streams between BSS/RNC and MNCC call forwarding. ran_msg.h provides a common API with abstraction for: - receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP or RANAP; - sending RAN events: ran_enc_msg is the counterpart to compose RAN messages that should be encoded to either BSSMAP or RANAP and passed down to the BSC/RNC and MS/UE. The RAN-specific implementations are completely contained by ran_msg_a.c and ran_msg_iu.c. In particular, Assignment and Ciphering have so far been distinct code paths for BSSAP and RANAP, with switch(via_ran){...} statements all over the place. Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified. Note that SGs does not qualify for RAN abstraction: the SGs interface always remains with the MSC-A role, and SGs messages follow quite distinct semantics from the fairly similar GERAN and UTRAN. * MGW and RTP stream management So far, managing MGW endpoints via MGCP was tightly glued in-between GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP streams between different RAN peers by moving to object-oriented implementations: implement struct call_leg and struct rtp_stream with distinct FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose. Instead of implementing a sequence of events with code duplication for the RAN and CN sides, the idea is to manage each RTP stream separately by firing and receiving events as soon as codecs and RTP ports are negotiated, and letting the individual FSMs take care of the MGW management "asynchronously". The caller provides event IDs and an FSM instance that should be notified of RTP stream setup progress. Hence it becomes possible to reconnect RTP streams from one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP peers (inter-MSC Handover) without duplicating the MGCP code for each transition. The number of FSM implementations used for MGCP handling may seem a bit of an overkill. But in fact, the number of perspectives on RTP forwarding are far from trivial: - an MGW endpoint is an entity with N connections, and MGCP "sessions" for configuring them by talking to the MGW; - an RTP stream is a remote peer connected to one of the endpoint's connections, which is asynchronously notified of codec and RTP port choices; - a call leg is the higher level view on either an MT or MO side of a voice call, a combination of two RTP streams to forward between two remote peers. BSC MGW PBX CI CI [MGW-endpoint] [--rtp_stream--] [--rtp_stream--] [----------------call_leg----------------] * Use counts Introduce using the new osmo_use_count API added to libosmocore for this purpose. Each use token has a distinct name in the logging, which can be a globally constant name or ad-hoc, like the local __func__ string constant. Use in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count API. * FSM Timeouts Introduce using the new osmo_tdef API, which provides a common VTY implementation for all timer numbers, and FSM state transitions with the correct timeout. Originated in osmo-bsc, recently moved to libosmocore. Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore) Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore) Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore) Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp) I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw) Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw) I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw) Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
2018-12-07 13:47:34 +00:00
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: + wait-Clear-Complete: now used by 1 (wait-Clear-Complete)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN encode: CLEAR_COMMAND on UTRAN-Iu
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Received Event MSC_I_EV_FROM_A_FORWARD_ACCESS_SIGNALLING_REQUEST
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - msc_a_fsm_releasing_onenter: now used by 2 (attached,active-conn)
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: RAN decode: CLEAR_COMPLETE
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: - wait-Clear-Complete: now used by 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: Received Event MSC_A_EV_UNUSED
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASING}: state_chg to MSC_A_ST_RELEASED
DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Released: msc_a use is 0 (-)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Removing from parent msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DVLR Process_Access_Request_VLR(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){PR_ARQ_S_DONE}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Removing from parent msub_fsm
DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: max total use count was 3
DMSC msub_fsm{active}: Received Event MSUB_EV_ROLE_TERMINATED
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) MSC-A terminated
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) 1 MSC-I still active
DMSC msub_fsm{active}: state_chg to terminating
DMSC msub_fsm{terminating}: Terminating in cascade, depth 2 (cause = OSMO_FSM_TERM_REGULAR, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Terminating in cascade, depth 3 (cause = OSMO_FSM_TERM_PARENT, caused by: msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ))
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Removing from parent msub_fsm
DMSC dummy_msc_i(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){0}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msub(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100) Free
DREF VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 - active-conn: now used by 1 (attached)
DMSC msub_fsm{terminating}: Deferring: will deallocate with msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ)
DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:CM_SERVICE_REQ){MSC_A_ST_RELEASED}: Deallocated, including all deferred deallocations
- msub gone
llist_count(&msub_list) == 0
DVLR freeing VLR subscr IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100 (max total use count was 4)
===== test_call_mo_to_unknown_timeout: SUCCESS
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20
full talloc report on 'msgb' (total 0 bytes in 1 blocks)
talloc_total_blocks(tall_bsc_ctx) == 20