From 3GPP TS 48.008 sec 3.1.30 "Common ID":
"""
If the SCCP connection is established due to CSFB from E-UTRAN and the MSC supports
return to the last used PLMN after CS fallback, then it should send the COMMON ID message
to the BSS including the Last used E-UTRAN PLMN ID information element if available at
the MSC immediately following the successful SCCP connection setup.
"""
Furthermore, 3GPP TS 48.008 version 16.0.0 Release 16 "3.2.1.21 CLEAR COMMAND",
for field CSFB Indication, states:
"""
NOTE: This information element doesn't serve any useful purpose. MSCs should not send the
information element unless it is required by the recipients (due to the need to interwork
with older versions of the protocol). It is expected that in future versions of the present
document, this information element will be deleted from this message.
"""
Hence, build up the EUTRAN neighbor list based on whether we received
the Last E-UTRAN PLMN ID IE during Common Id. In the future, we should
probably filter the list while populating it based on the received IE.
This change will also allow reusing same mechanism for SRVCC
EUTRAN->GERAN support, where te Last E-UTRAN PLMN ID IE can be found
inside "Old BSS to New BSS information" IE in msg HANDOVER REQUEST.
Related: SYS#5337
Change-Id: I5d290ac55eca5adde1c33396422f4c10b83c03d5
The neighbor configuration storage is fundamentally broken: it requires
all local cells to be configured before being able to list them as
neighbors of each other. Upon config write-back, the neighbor config
however is placed back inline with the other config, and hence a
written-out neighbor config no longer works on program restart.
The cause of this problem is that the config is stored as explicit
pointers between local cells (struct gsm_bts), which of course requires
the pointer to exist before being able to reference it.
Instead, store the actual configuration that the user entered as-is,
without pointers or references to objects that need to be ready. Resolve
the neighbors every time a neighbor is needed.
Hence the user may enter any config at any place in the config file,
even non-working config (like a BTS number that doesn't exist), and the
relation to actual local or remote neighbor cells is made at runtime.
Abort program startup if the initial neighbor configuration contains
errors.
Related: OS#5018
Change-Id: I9ed992f8bfff888b3933733c0576f92d50f2625b
So far the list of penalty timers was stored for an opaque target
pointer. That was either a gsm_bts pointer for a local BTS, or a cell
identifier list pointer for a remote-BSS cell.
Reasons to refactor penalty timers:
- The cell identifier list pointer came from the neighbor configuration
storage, but the way cell neighbor config is stored will change in a
subsequent patch. There will be no more cell identifier lists there.
- Storing object pointers is inherently unsafe -- if an object gets
removed and another gets allocated, the penalty timer could
theoretically remain in force for an unrelated object.
Rather store penalty timers for specific Cell IDs. Since remote-BSS
neighbors can be requested by a cell identifier *list*, use a
gsm0808_cell_id_list2 as key in the list of penalty timers.
Fix handover_test.c: have different CI for each local BTS. So far it was
the same LAC+CI for all BTSes, which now would make the test fail,
because any penalty timer would appear to apply to all local cells.
Related: OS#5018
Change-Id: I72dd6226a6d69c3f653a3174c6f55bf4eecc6885
On lchan activation, we already know the Timing Advance in most
situations: from the Channel Request RACH, or from a previous lchan in
the same cell. Place this information in lchan->activate.info.ta.
So far, the lchan->last_ta (until recently called rqd_ta) was used to
store the initial TA for channel activation -- move the initial TA to
lchan->activate.info.ta, for proper scoping.
Only an inter-cell handover does not yet know a Timing Advance (until
the Handover Detection RACH is received), so indicate
activate.info.ta_known = false for that case.
If ta_known is false, do not include an Access Delay IE in the Channel
Activation message, ensuring that the BTS does not use an arbitrary TA
that is likely inaccurate.
The effect for OsmoBTS is that we will *not* start the downlink SACCH on
channel activation for inter-cell handover, but will wait for a HO RACH
first, and then use the correct TA when enabling downlink SACCH.
Related: OS#4008 SYS#5192
Change-Id: I986bf93e8acd6aef7eaf63ac962480b680aa894f
This is a non-standard RSL message that must be sent after each traffic
channel has been established. Without it, any voice call will be
disconnected within seconds.
This is a hack; we need to store the subscribers classmark2 value and
use it here.
Change-Id: I6cb6d25e405aa888c4df4022d897330a6af9e946
Related: OS#2389
An inter-BSC-OUT handover ends with a Clear Command, which HO_OUT_ST_WAIT_CLEAR
waits for. Actually tell the handover_fsm.c about an incoming Clear Command, so
that the inter-BSC-OUT success can be counted.
Similarly, count failing handover results for an unexpected Clear Command from
the MSC.
Related: OS#4736
Change-Id: I0c489838a99f930e2104619ca745191d2a736f1b
So far, during inter-BSC outgoing handover, when receiving an RR Handover
Failure from the MS, it would be counted as 'error'. Instead, add the 'failed'
counter like for all other HO types.
It may make sense to omit the 'failed' counter for inter-BSC *incoming*
handover, because then we won't receive an RR Handover Failure message. I
probably got those two mixed up during initial development.
Related: OS#4736
Change-Id: I9a61d5cc7273a830ba4e66e43e4aac6cdb707471
To handle cases of unknown handover type (like failure to find the target
cell), return -1 as counter code; treat -1 as skipping in ho_count_bsc() and
ho_count_bts().
The handover:* counters indicate overall counts, without knowing whether inter-
or intra-BSC, or whether the target ARFCN even exists. So they need to be
counted separately, and must not serve as fallback category in
result_counter_bsc() and result_counter_bts().
Related: OS#4736
Change-Id: Ie311e599d7bd35d33cf471c6c63e649246e8396a
Move initial 'handover:attempted' counts from bsc_subscr_conn_fsm.c to
handover_fsm.c, where all the other counters are handled.
Add missing increments for the overall 'handover:*' counts.
Related: OS#4736
Change-Id: I783bdedafc0eb8f2df9ea100792846fecc7ccbf7
In some (error-) cases we might be unable to determine which BTS to use
when counting handover events. We don't want to loose these events
because then ctr(bsc) == sum(ctr(bsc->bts)) would not be true anymore.
Those events are now counted by a counter in struct gsm_network which
uses an index that is out of range for regular BTS (65536).
Change-Id: Ic0f3edd5dc014c4eac5e8423133633a3e5d4c13e
Related: SYS#4877
Currently the counters don't distinguish between intra-cell and
intra-bsc handover.
Add _CTR_INTRA_CELL_HO_ and _CTR_INTRA_BSC_HO_ counters to track
intra-cell/bsc handover separately.
Change-Id: I3a1195640b99813036c9f1426ee5f07548e26547
Related: SYS#4877
Our current handover counters only count success/failures per BSC. It
would be nice to also count which BTS is part of a (successful/failed)
handover.
This patch duplicates the BSC counters for the BTS and changes the
ho_count and related macros to also count per BTS. If a BTS is NULL
(when conn->lchan is NULL) counting for the BTS is ignored.
Change-Id: I025ef14e2cfd2eea8880212c9406372ce0bf9296
Related: SYS#4877
Place all code related to the object into the related file.
Having all the data model in one file made sense in early stage of
development to make progress quickly, but nowadays it hurts more than
helps, due to constantly growing size and more and more bits being
added to the model, gaining in complexity.
Currently, having lots of different objects mixed up in gsm_data.h is a hole
of despair, where nobody can make any sense were to properly put new stuff
in, ending up with functions related to same object in different files
or with wrong prefixes, declarations of non-existing functions, etc.
because people cannot make up their mind on strict relation to objects
in the data model.
Splitting them in files really helps finding code operating on a
specific object and helping with logically splitting in the future.
Change-Id: I00c15f5285b5c1a0109279b7ab192d5467a04ece
We already have counters for Rx side, now we also count Tx side.
See comments in the msc_ctr_description array implementation for
the details.
Change-Id: I89a173f6bdd9a3c21233fe01d07ab2ff0442bb10
Fix neighbor config to match OsmoBSC manual: implement the plan for neighbor
configuration that was so far only described in the manual without actually
being in operation.
This first allows re-using ARFCN+BSIC pairs in and across BSS.
So far the handover_start() code always looked for handover target cells across
*all* local cells, even if they were not listed as neighbors to a source cell.
Imply all cells as neighbors only as long as there are no explicit neighbors
configured. As soon as the first 'neighbor' line appears in a 'bts' config,
only the listed neighbors are regarded as handover target cells. (The
'neighbor-list' commands are not related to this, only the relatively new
'neighbor (bts|lac|cgi|...)' commands affect actual handover procedures.)
TTCN3 tests TC_ho_neighbor_config_1 thru _7 play through the various aspects of
neighbor configuration: both the legacy implicit all-cells-are-neighbors as
well as allowing only explicit neighbors by config.
Related: OS#4056
Related: osmo-ttcn3-hacks Ia4ba0e75abd3d45a3422b2525e5f938cdc5a04cc
Change-Id: I29bca59ab232eddc74e0d4698efb9c9992443983
If no target cell got selected in a handover attempt, enum value NO_HANDOVER is
used. In that case, do not log a lot of errors saying
"invalid enum handover_scope value: none" -- they are misleading.
Change-Id: I98e748bea58ebb02812b6aaa6431c7d4b813242d
Clarify some in-code comments.
Fix descriptions of some handover timers, which still talked of "MO" and "MT"
handover -- which we now call "inter-BSC out" or "inter-BSC in" instead.
Change-Id: I8429a830edd0325893ac90f22fcc05309617bd2d
Move the HO_ST_WAIT_MGW_ENDPOINT_TO_MSC state up to right after the lchan is
done establishing. For AoIP, the local RTP address towards the MSC already
needs to be known before the Handover Request Acknowledge is sent, so the AoIP
Transport Layer Address IE can be included. This patch only modifies the
handover FSM, a subsequent patch adds the IE.
Change-Id: I00c18b78573386145af71c4b39f7f22aec24579b
To support the 3 possible preferences, the changes needed were:
- Replace 'full_rate' bool with a 3 option enum to represent
the channels types for signalling
- Switch from _pref/_alt to using an array sorted in preference
order
Originally merged as Change-Id I4c7499c8c866ea3ff7b1327edb3615d003d927d3,
reverted because the change broke voice calls. Re-submitting with the fix:
don't forget to set conn->assignment.requires_voice_stream.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Change-Id: I7513d2cbe8b695ba6f031ad11560c63a6535cf2d
osmo-mgw.git also includes fixes of the MGW endpoint FSM, for example
I92a9944acc96398acd6649f9c3c5badec5dd6dcc.
Depends: I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw)
Change-Id: I03e6b48d9b0a5370310d5f56809259ff7909cf9d
Move the T_defs API to libosmocore as osmo_tdefs: remove the local T_defs API
and use libosmocore's osmo_tdef* API instead.
The root reason is moving the mgw_endpoint_fsm to libosmo-mgcp-client to be
able to use it in osmo-msc for inter-MSC handover.
When adding osmo_tdef, the new concept of timer groups was added to the API. It
would make sense to apply group names here as well, but do not modify the VTY
configuration for timers. The future might bring separate groups (or not).
Depends: Ibd6b1ed7f1bd6e1f2e0fde53352055a4468f23e5 (libosmocore)
Change-Id: I66674a5d8403d820038762888c846bae10ceac58
This reverts commit 94c9324fe0.
Multiple ttcn3 handover tests were broken due to this commit. Let's
merge this once all the other commits pertaining to that fix can be
merged as well.
Fixes: OS#3942
Change-Id: I01d93778fb19c601c21f99ec4d2a3ab8a4a48f67
Move the HO_ST_WAIT_MGW_ENDPOINT_TO_MSC state up to right after the lchan is
done establishing. For AoIP, the local RTP address towards the MSC already
needs to be known before the Handover Request Acknowledge is sent, so the AoIP
Transport Layer Address IE can be included. This patch only modifies the
handover FSM, a subsequent patch adds the IE.
Change-Id: I4a5acdb2d4a0b947cc0c62067a67be88a3d467ff
During inter-BSC-incoming, the MSC sends the chosen encryption algorithm in the
Handover Request message. Actually parse this Chosen Encryption Algorithm IE.
Place the chosen algorithm and the CK into lchan_activate_info->encr so that
the new lchan will use the same ciphering on this new BSS as it did on the old
BSS.
Change-Id: I5b269f50bd2092516bfdf87746196983d3ac49d1
For intra-BSC handover, the previous encryption is copied from the old lchan,
which of course is not available during inter-BSC handover. Hence the lchan
activation info needs to include an explicit encryption information, and we
must not rely on the presence of the previous lchan to copy encryption
information from.
Add struct lchan_activate_info.encr to allow passing encryption info through
lchan_activate() without requiring a previous struct gsm_lchan to be present.
Instead of copying from the old lchan, always copy encryption info to
lchan_activate_info, and during activation, just before sending the Channel
Activation, copy the lchan_activate_info.encr to the new lchan.
This prepares for upcoming I5b269f50bd2092516bfdf87746196983d3ac49d1 which
obtains the encryption information from an intra-BSC-incoming Handover Request
message.
Related: OS#3842
Related: I5b269f50bd2092516bfdf87746196983d3ac49d1
Change-Id: Ib3d259a5711add65ab7298bfa3977855a17a1642
This commit breaks voice channel assignment. It results in the
Assignment Complete sent to the MSC for a voice lchan lacking
AoIP Transport Layer Address, Speech Version and Speech Codec.
Hence the MSC cannot complete the Assignment for a voice call.
Let's revisit this patch, test thoroughly and re-merge later.
This reverts commit 4d3a21269b.
Reason for revert: <INSERT REASONING HERE>
Change-Id: I72aaa03539919e7e85b5b75b133326cec5e68bc9
To support the 3 possible preferences, the changes needed were:
- Replace 'full_rate' bool with a 3 option enum to represent
the channels types for signalling
- Switch from _pref/_alt to using an array sorted in preference
order
Change-Id: I4c7499c8c866ea3ff7b1327edb3615d003d927d3
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
When a new lchan is selected during handover, some of the properties of
the old lchan are inherited by the new lchan. At the moment S15-S0 is
not not inherited so that the value for those bits will always be 0x0000
for the new lchan. Since those bits also define the active set AMR codec
the channel activation will fail because 0x0000 is invalid (active set
with zero rates)
Change-Id: Ifd470397e99985394634da1bb13ccfc5041984d2
Related: OS#3503
When the MSC allocates a channel through the ASSIGNMENT REQUEST, it may
ask for a TCH/H and a TCH/F at the same time and tell which of the two
types it prefers.
The process of channel allocation currently selects, based on the BTS,
MSC and MS capabilites exactly one apropriate codec/rate (e.g. TCH/H)
and then tries to allocate it. If that allocation fails, there is no way
to try the second choice and the assignment fails.
For example: The MSC asks for TCH/F and TCH/H, prefering TCH/F, then the
channel allocator will try TCH/F and if it fails (all TCH/F are
currently in use), then TCH/H is never tried.
Since the BSC currently only trys the first best codec/rate that is
supported it also ignores the preference.
Lets fix those problems by including the preference information and both
possible codec/rate settings into the channel allocation decision.
Change-Id: I5239e05c1cfbcb8af28f43373a58fa6c2d216c51
Related: OS#3503
handover_fsm.c accesses conn->assignment.req.s15_s0 to find out the current
lchan's AMR configuration. However, conn->assignment.* values are only valid
during an ongoing assignment. Those values may be overwritten by any failed
Assignment attempt, at any time, and hence do not reflect the currently
assigned conn->lchan. Those realms must be kept separate.
The assignment.req.s15_s0 get passed to lchan_activate(), so it makes most
sense to store these values in struct gsm_lchan once the lchan activation
succeeded.
Add gsm_lchan.s15_s0, store the s15_s0 received in lchan_activate_info during
lchan_activate().
In handover_fsm.c, use conn->lchan->s15_s0 instead of conn->assignment.*.
Change-Id: Id8018fd9d56421f2ab7be91703018f6d6f21c929
Fix crash after AMR configuration fails.
The crash is due to an assertion that finds a non-NULL conn in the lchan, when
re-using an lchan that has failed in AMR configuration earlier on. That is
because the AMR config still happens in state UNUSED.
DCHAN ERROR lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: (type=TCH_F) lchan allocation failed in state UNUSED: Can not generate multirate configuration IE
...
DCHAN DEBUG lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: (type=TCH_F) After failure handling, already in state UNUSED
...
...
DCHAN DEBUG lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: Received Event LCHAN_EV_ACTIVATE (lchan_fsm.c:324)
Assert failed !lchan->conn ../../../../src/osmo-bsc/src/osmo-bsc/lchan_fsm.c:491
The FSM design idea is that when returning to the UNUSED state, all lchan state
is cleared. However, when calling lchan_activate(), a failure may happen still
in state UNUSED, so that we don't transition *back* to UNUSED properly.
So, first transition out of UNUSED before failures can happen. (Other ways to
solve this would be to invoke lchan clearing even if already in UNUSED, but
semantically, transitioning first makes more sense.)
Upon LCHAN_EV_ACTIVATE, just remember the lchan_activate_info and transition to
WAIT_TS_READY, so that on lchan_fail(), we can normally transition back to
UNUSED and clear the lchan.
Move the initial lchan activation code to lchan_fsm_wait_ts_ready_onenter().
Also, there is a bit of duplication of members of the lchan->activate (lchan
state) and the lchan_activate_info (passed to lchan_activate()) structs. The
fix for this also removes the dup:
Add struct lchan_activate_info as child struct at lchan->activate.info, drop
the other lchan->activate members that would dup .info.*. Move struct
lchan_activate_info declaration to gsm_data.h.
Apply the new '.info' member struct throughout the code.
Related: OS#3737
Change-Id: Ide665b10fa3f4583059c55346db8da833959e3cc
When an internal handover is done the specification demands to inform
the MSC about the event.
- Add sending of BSSMAP HANDOVER PERFORMED msg.
Change-Id: If26e5807280e0f75a423b3b04f8e3c698c82a351
Depends: libosmocore I825106858bd89afc9837811b8fed2e8accc82441
Related: OS#3645
If an lchan is being released and had a SACCH active, there is no reason to
omit the Deact SACCH message ever. All of the callers that passed
do_deact_sacch = false did so for no good reason.
Drop the do_deact_sacch flag everywhere and, when the lchan type matches and
SAPI[0] is still active, simply always send a Deact SACCH message.
The do_deact_sacch flag was carried over from legacy code, by me, mainly
because I never really understood why it was there. I do hope I'm correct now,
asserting that having this flag makes no sense.
Change-Id: Id3301df059582da2377ef82feae554e94fa42035
After commit [1], the code makes sure to disassociate lchan and conn before
invoking the lchan release. However, we only send RR Release if a conn is
present, which clearly is nonsense after [1].
[1] commit 8b818a01b0
"subscr conn: properly forget lchan before release"
Change-Id: I4fd582b41ba4599af704d670af83651d2450b1db
Manage sending of RR Release via a flag, set during invoking lchan release.
Add do_rr_release arg to lchan_release(), gscon_release_lchans(). In
lchan_fsm.c, send RR Release only if do_rr_release was passed true; do not care
whether a conn is still associated (because it won't ever be since [1]).
That way we can intelligently decide what release process makes sense (whether
the lchan terminates the subscriber connection or whether the connection goes
on at another lchan), and still disassociate lchan and conn early.
BTW, this problem wasn't caught by the stock OsmoBSC TTCN3 tests, because the
f_expect_chan_rel() don't care whether an RR Release happens or not. This is
being fixed by Ibc64058f1e214bea585f4e8dcb66f3df8ead3845.
So far this patch should fix BSC_Tests_LCLS.TC_lcls_connect_clear.
Related: OS#3413
Change-Id: I666b3b4f45706d898d664d380bd0fd2b018be358
The chan mode is figured out per-BTS, but may remain uninitialized. Rather log
info about the channel request, like further above.
Change-Id: I07b89b6101879fb7c070c87be9bd38cc05ffa0b1
Inter-BSC outgoing lacked the required BSSMAP HO Failure dispatch.
Not all cases should send BSSMAP HO Failure, name the relevant spec paragraphs
in comments and adjust handling.
Related: osmo-ttcn3-hacks If772dbbc5f9790d3f911465e1303dd0a99811154
Change-Id: I0980cacb9713e41a1eef3a0a7f6cc892e8a20da5
Opposed to all other codecs that are common in GSM, AMR requires a codec
configuration that is expressed by a bitmask (S0 to S15) in the speech
codec list in the ASSIGNMENT REQUEST. Also the BSC acknowledges those
configuration in the ASSIGNMENT COMPLETE message.
At the moment osmo-bsc ignores all incoming configuration bits. The bits
in the ASSIGNMENT COMPLETE speech codec (choosen) field are hardcoded.
- Store the configuration bits while parsing the ASSIGNMENT COMPLETE
- Create an intersection with the configuration that is actually
supported by the BSS
- Return the resulting (chosen) configuration bits with the assignment
complete message.
- Use the (highest of the) agreed codec rates in RSL channel activation.
Change-Id: I2d8ded51b3eb4c003fe2da6f2d6f48d001b73737
Related: OS#3529
Before, this would ignore the failure and hit a timeout instead. Rather handle
the event directly.
Change-Id: I21c43d2907d0413ef18ec43cf27f680ebecf9e82
Drop nonsensical legacy code.
The Circuit Identifier Code in A/SCCPlite does *not* indicate the RTP port to
use. Rather, it indicates the MGW endpoint name to use when configuring the
BSC's side of the MGW endpoint, and only the MGW will ever know the RTP port.
Change-Id: I471bd5e5cc2a083dd37290aeaae5c334ca5f7eed
3GPP mandates either Classmark Information 1 or 2 in BSSMAP Handover Request,
but an SCCPlite MSC currently tested does not pass either of them. Make this
missing IE a non-fatal error, continuing anyway should work out.
See 3GPP TS 48.008, 3.2.1.8 HANDOVER REQUEST, where it says "Classmark
Information 1 or Classmark Information 2" with note 6: "One of these two
elements is sent."
Change-Id: I34d64b028210b4df8652fee1a8830ec4a4e3ac11
Pau Espin
Neels Hofmeyr
Harald Welte
Daniel Willmann
Martin Hauke
Sylvain Munaut
Neels Hofmeyr
Philipp Maier