This patch served for a manual testing counterpart for osmo-bsc to implement
MSC pooling.
This enables a basic MSC pooling setup, but for a production setup, osmo-msc
would still lack various features related to unloading subscribers to another
MSC as explained in 3GPP TS 23.236.
Change-Id: Iafe0878a0a2c8669080d757b34a398ea75fced36
The Mobile Identity type is received on the wire, we asserting on its type
constitutes a DoS vector.
Change-Id: I2b2e25ef8e878e91a165018ba49f1609cfb5cbd0
Since the split of OsmoNiTB, OsmoMSC does not deal with the radio
access network directly. Therefore the only purpose of T3212 is to
control subscriber expiration in the local VLR. The timeout value
indicated in System Information Type 3 needs to be configured
separately in the BSC/RNC.
This means that we don't need to store it in deci-hours anymore.
Let's move T3212 to the group of VLR specific timers, so it can
be configured and introspected using the generic 'timer' command,
and deprecate the old '[no] periodic location update' command.
It should be also noted that in the old code subscriber expiration
timeout was actually set to twice the T3212 value plus one minute.
After this change, we apply the configured value 'as-is', but
keep the old behaviour for 'periodic location update' command.
Change-Id: I9b12066599a7c834a53a93acf5902d91273bc74f
These timers so far were implemented as a list of unsigned integers,
which has never been initialized to any reasonable defaults. Since
they are used as state timeouts in several FSMs, we might end up
staying in some state forever.
Let's migrate to generic osmo_tdef API and use default values from
table 11.2 of 3GPP TS 24.008. This way the user can introspect and
change their values from the VTY / configuration file.
Change-Id: Ia8cf98da0aea0e626c5ff088a833d7359c43847f
Related: OS#4368
In order for osmo-hlr to be able to 100% guarantee distinct INDs for CS and PS,
set CN-Domain = CS in all SendAuthInfo Requests.
In Milenage auth, it is highly desirable that osmo-hlr guarantees use of
distinct INDs for CS and PS domains. If an MSC and SGSN attached at the same
time use the same IND bucket to generate Milenage SQN, that collision would
rapidly waste SQNs and load osmo-hlr with requesting new auth tuples on each
CS/PS Complete-Layer3.
So far, osmo-msc did not indicate the CN domain in the GSUP SendAuthInfo
Request, which was neither required nor evaluated. The CN-Domain is only sent
for the UpdateLocation Request that usually follows later.
Related: OS#4318
Change-Id: I22f44068268e62801cadbf6542efaf153423cd65
When a vlr_subscr receives an Send Auth Info result, properly check whether the
subscriber has an auth_fsm.
Before, a missing auth_fsm would crash osmo-msc with:
vlr.c:762 Trying to dispatch event 1 to non-existent FSM instance!
Related: OS#4191
Change-Id: I1995d8f68cfde1140968fb9a97bd054de950de2e
It's always set to OSMO_TERM_ERROR. Move the assignment to the caller.
In prepartion to use gmm_cause_to_fsm_and_mm_cause() in vlr_auth_fsm.
Change-Id: Ie4720ad40ef7bcfc528d8d63bfc606c9c0545fb2
If an ID Response comes in during a non-LU L3 Complete (Paging or CM Service
Request), no event needs to be dispatched. So far vlr_subscr_rx_id_resp()
logged a NOTICE "gratuitous ID RESPONSE?!?" if no lu_fsm is present.
An ID Response can come in particularly as payload with a BSSMAP Cipher Mode
Complete message, even though osmo-msc didn't explicitly ask for it.
It is not an error to get a Cipher Mode Complete containing an ID Response
during Paging or CM Service Request, so remove the confusing log message.
Related: OS#4168 (only loosely related)
Change-Id: I8a5b8735eb41cd0976c7ab32cdd55440d3ef70ac
When periodic Location Update is disabled (T3212 = 0), it was noticed
that OsmoMSC does expire subscribers quite soon - after 60 seconds
(VLR_SUBSCRIBER_LU_EXPIRATION_INTERVAL) since the last LU.
In order to avoid that, we need to check T3212 timer value in
vlr_subscr_expire_lu(), and if it's equal to 0, do not expire
anybody until the explicit IMSI Detach.
Change-Id: I2ead2241a3394dbdd5417f4554190df3fd698af2
reported by _dev_zero in #osmocom
Change-Id: Ib5679ab5d06b6ef735725b4a68eeb1e9cbcc11ba
Depends-On: libosmocore I52b9f6b5f3e96d85a390ba2af21d7814df8aaeec
The HLR (which is connected via the GSUP interface) may fail and
disconnect. On the next location update the VLR will try to talk to the
HLR and fail. This failure event is not communicated towards the SGs
related code and the SGs-association will remain in the LA-PRESENT state
forever. Lets add code to report the problem to the SGs code and trigger
a RESET an the SGs interface.
- Add a flag to report an HLR problem back to the SGs code
- Fix the FSM that controls the reset
- Make sure the all SGs associations are reset when the failure occurs.
Change-Id: Icc7df92879728bc98c85fc1d5d8b4c6246501b12
Related: OS#3859
When 'check-imei-rqd 1 early' is set in the config, send the IMEI to
the HLR before doing the location update with the HLR.
The OsmoHLR documentation referenced in the code will be added in
osmo-hlr.git's Change-Id I2dd4a56f7b8be8b5d0e6fc32e04459e5e278d0a9.
Related: OS#2542
Change-Id: I88283cad23793b475445d814ff49db534cb41244
Copy IMEISV to IMEI when IMEISV changes. The additional SV digits will
get cut off then. This is needed for the subscriber on demand use case,
since we can get the IMEISV early (see [1]), but need to send the IMEI
to the Check IMEI procedure.
While adjusting the tests, I have noticed that there are code paths
where we ask the MS for the IMEISV first, and later ask the MS for the
IMEI, although we already have the IMEISV. This could be improved in a
future patch.
[1] Change-Id I256224194c3b8caf2b58a88d11dccd32c569201f
Related: OS#2542
Change-Id: I02e7b66848bf7dddb31b105e2ae981432817ae1e
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
We now have a nicer way to compose strings in a buffer than this.
(Cosmetic preparation for inter-MSC handover patch.)
Change-Id: I7813068032475deb3850af05f7ba5a6f652e7fa2
Add an SGs interface (3GPP TS 29.118) to osmo-msc in order to support
SMS tunneling and Circuit Switched Fallback (CSFB)
Change-Id: I73359925fc1ca72b33a1466e6ac41307f2f0b11d
Related: OS#3615
When check-imei-req is enabled in the VTY config, do not accept IMEIs
sent by the ME directly anymore. Send the IMEI to the EIR/HLR and wait
for its ACK or NACK.
OsmoHLR also accepts all IMEIs at this point, but this allows to
optionally store the IMEI in the HLR DB.
Depends: Ib240474b0c3c603ba840cf26babb38a44dfc9364 (osmo-hlr)
Related: OS#3733
Change-Id: Ife868ed71c36cdd02638072abebf61fc949080a7
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
Make the vsub argument of both vlr_subscr_msisdn_or_name()
and vlr_subscr_name() a const.
The LOGVSUBP() macro uses vlr_subscr_name() and will not generate a
warning anymore when used with a const vsub.
Change-Id: If609269191f4df6186d823a2eee14012846328e2
Add a 'ipa-name' VTY command which overrides the default IPA name
used by the MSC. This is a prerequisite for inter-MSC handover.
Related: OS#3355
Change-Id: I317d6c59f77e92fbb2b875a83dc0ec2fa5cb6006
When a subscriber is cancelled, fake an IMSI detach to
ensure that the subscriber gets removed from the VLR.
I am not entirely sure if this change is correct but
it does make TTCN3 test MSC_Tests.TC_gsup_cancel pass.
Change-Id: I5918106e4a94ba2e6c61bcd7b90d3bf0565513cc
Related: OS#2886
Along goes GSM_KEYSEQ_INVAL as VLR_*.
It's where it logically belongs, and is almost the only reason why vlr.h
includes gsm_data.h. The remaining reason, GSM_EXTENSION_LENGTH, will be moved
by upcoming patch.
Change-Id: I122feae7ee3cbc59e941daef35a954bce29fec76
In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.
* Name choice:
In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.
The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.
* Rationale:
A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.
Also:
- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*
Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
the function vlr_subscr_req_lu() has a parameter is_ps, which is set
to vsub->vlr->cfg.is_ps by the only caller in vlr_lu_fsm.c. Inside the
function one can see that vsub->vlr->cfg.is_ps is used directly to
decide between PS or CS LU, we could also use is_ps there. Presumably
the parameter is_ps had been abandonned in an early development stage
and was not removed, so lets drop the parameter.
Change-Id: Id239721773b90099d122b232dae1ba457be9d255
Give the HLR a chance to send us updated subscriber data by indicating the CN
domain to be Circuit Switched, only during a LU Request GSUP message.
Adjust msc_vlr_tests to expect the added GSUP CN domain IE to indicate CS, i.e.
append '280102'.
Related: OS#3601
Change-Id: I0c2d33fbfdb4728e480679120d06b7f3a2ccfd76
osmo-hlr has recently (as of Change-Id
Iad227bb477d64da30dd6bfbbe1bd0c0a55be9474) a working shared library
implementation of libosmo-gsup-client.
We can remove the local implementation in osmo-msc and use the
system-installed shared library instead.
Change-Id: I6f542945403cf2e3ddac419186b09ec0e2d43b69
Some internal sub-systems, such as SS/USSD or SMS implementation,
may also need to use GSUP connection with HLR. Previously, it was
only available within the libvlr code, and nowhere else.
Let's introduce the generic GSUP message router, which will
receive messages unhandled by VLR itself, and route them to
a handler depending on the message type.
Change-Id: Ib8146ce5788c8f249dcaa39d61bd0388574bf892
Overlong IMSIs in ID RESP messages were accepted and used in
truncated form.
Log an error when truncation occurs, and prevent truncated IMSIs
from being installed for a subscriber via ID RESP messages.
Other code paths leading to vlr_subscr_set_imsi() with truncated
IMSIs will only a leave a trail of log entries for now, because
vlr_subscr_set_imsi() is currently unable to return an error code.
Change-Id: I785c994f41a646d8d83d3d82f5a9ae6b572eb641
Related: OS#2864
Remove subscribers which fail to send periodic Location Updates from the
list of subscribers known to the VLR. This complements the IMSI detach
procedure: periodic LU expiry triggers an implicit IMSI detach.
Expired subscribers are purged from a periodic timer which iterates
over all subscribers once per minute.
Subscribers with an active connection do not expire. This is controlled
by the subscriber conn FSM which sets a subscriber's the LU expiry timeout
value to GSM_SUBSCRIBER_NO_EXPIRATION while a connection is active.
Add support for fake time with osmo_clock_gettime() to msc_vlr tests.
This functionality existed in OpenBSC but was lost during the nitb split.
This code took some inspiration from the OpenBSC implementation.
Related: OS#1976
Change-Id: Iebdee8b12d22acfcfb265ee41e71cfc8d9eb3ba9
Instead of keeping separate enums for FSM results and translating between those
and the actual 04.08 reject causes that will ultimately reach the MS, just pass
enum gsm48_reject_value cause codes around everywhere.
Collapse some VLR *_timeout() and *_cancel() api to just *_cancel() with a
gsm48 cause arg.
(Hopefully) improve a few reject causes, but otherwise just aim for more
transparent decisions on which cause value is used, for future fixes of
returned causes.
Depends: I6661f139e68a498fb1bef10c266c2f064b72774a (libosmocore)
Change-Id: I27bf8d68737ff1f8dc6d11fb1eac3d391aab0cb1
Drop tall_bsc_ctx; in mncc_sock_init(), talloc the mncc_sock_state from
gsm_network.
In tests or utils, move from using an extern tall_bsc_ctx to a local root
context pointer.
Change-Id: I92c252be1d1e7634f1653de47d37c99d77d9501c
Check and handle gracefully any error which might appear in
osmo_gsup_encode() - mark corresponding functions with
warn_unused_result attribute to make sure this failure is always checked
against.
Change-Id: I4551212011fb0bd898c020a183756ed7a9afb9e5
Related: OS#2864
We don't usually put space before in-place increment or decrement. Let's
make code look similar to other Osmocom projects.
Change-Id: I5962431ad16c97e412939dc1b8949f6361a5c26e
Using following semantic patch:
@@ expression A, B, C; @@
- osmo_strlcpy(A, B, sizeof(A));
+ OSMO_STRLCPY_ARRAY(A, B);
Which was applied using following command:
spatch --dir src -I src --sp-file strlcpy.spatch --in-place --recursive-includes
All the calls to osmo_strlcpy() which use destination buffer obtained
via sizeof() were replaced with the corresponding wrapper macro.
Change-Id: I67b482dedfa11237ac21894fc5930039e12434ab
Related: OS#2864
The VLR code seems to have the assumption that there is one particular
algorithm to be used, as opposed to one of a set of algorithms.
What's missing is basically to decide when/where to pick the best
algorithm within the capabilities of the phone (classmark) and the
network configuration (net->a5_encryption_mask). So far, libvlr has no
notion of classmark. Rather, libmsc has.
Why does the VLR care about the particular algorithm at all? The VLR
should probably simply decide if it should use encryption or not, and if
so, the MSC will figure which algorithm to use.
Change-Id: I5ed80ca2086560a5975a758ec568a034a9a8ab89
* move log helpers to generic header
* log subscriber update
It's handy for troubleshooting issues with subscriber update via GSUP
from HLR.
Change-Id: I1958aeeb3ea99831c7e2c5ee9a6b59834baf4520
This avoids potential licensing incompatibility and makes integration of
Debian packaging patches easier.
Related: OS#1694
Change-Id: I71cd631704a4dc155c6c752fee2a42cd6e2fa336
In case of UMTS AKA, the Kc for ciphering must be derived from the 3G auth
tokens. tuple->vec.kc was calculated from the GSM algorithm and is not
necessarily a match for the UMTS AKA tokens.
To decide (in an upcoming patch) whether to use UMTS AKA derived Kc or the Kc
from the auth vector, the set_ciph_mode() from vlr_ops needs to know whether
UMTS AKA is being used. This could possibly derived from the msc_conn_ref, but
all flags are already available in the vlr_lu_fsm and vlr_access_req_fsm. Hence
add a umts_aka flag to the set_ciph_mode() callback invocation. The VLR FSMs
thus decide whether UMTS AKA or GSM AKA is to be used during Ciphering Mode
Command, which makes more sense than re-implementing the same decision process
in the MSC.
I considered placing the Kc derivation in vlr_set_ciph_mode() and only tell the
MSC's set_ciph_mode() implementation the precise keys it should use, but the
RAN particulars, and whether a Kc is used at all, rather belong with the MSC.
Related: OS#2745
Prepares: If04e405426c55a81341747a9b450a69188525d5c
Change-Id: I983c48347faf4ee1b405d8174b4e006c904157cf
Neels Hofmeyr
Martin Hauke
Eric Wild
Philipp Maier
Oliver Smith
Harald Welte