Project

General

Profile

Bug #2854

OsmoMSC never updates bearer capability from MNCC

Added by laforge 4 months ago. Updated 3 months ago.

Status:
Resolved
Priority:
High
Assignee:
Category:
-
Target version:
-
Start date:
01/22/2018
Due date:
% Done:

100%

Resolution:

Description

In a voice Call, it appears that trans->bearer_cap (with e.g. the list of supported codecs) is only initialized when receiving CC SETUP, CC CALL CONFIRMED, CC MODIFY and CC COMPLETE.

There appear to be no MNCC messages by which an external MNCC handler can have any influence on the contents of trans->bearer_cap.

However, trans->bearer_cap is exactly what is used to determine the voice codec when encoding the BSSMAP ASSIGNMENT towards the BSC.

From my point of view, the external MNCC handler should be able to specify the permitted codecs at any time, for example in a MO call in (at least) the following primitives:
  • MNCC_CALL_PROC_REQ
  • MNCC_SETUP_COMPL_REQ

The normal operation would be for the MNCC handler to intersect the permitted codecs as received from the MNCC_SETUP_IND (i.e. decoded from CC SETUP) with whatever it is capable of handling on the external PBX side, or with local policy. The returned set of codecs then is passed back via MNCC, trans->bearer_cap updated and finally the related BSSMAP ASSIGNMENT codec list computed.


Related issues

Related to OsmoMSC - Feature #2832: MNCC doesn't include field for "supported codecs" New 01/16/2018
Related to osmo-sip-connector - Bug #1683: osmo-sip-connector: Implement codec selection New 03/31/2016
Related to OsmoNITB - Bug #1663: don't connect channels of incompatible voice codec Closed 03/17/2016
Related to OsmoMSC - Bug #2933: change of trans->bearer_cap (e.g. via MNCC) will not trigger BSSMAP ASSIGNMENT New 02/12/2018

History

#1 Updated by laforge 4 months ago

  • Related to Feature #2832: MNCC doesn't include field for "supported codecs" added

#2 Updated by laforge 4 months ago

  • Related to Bug #1683: osmo-sip-connector: Implement codec selection added

#3 Updated by laforge 4 months ago

  • Related to Bug #1663: don't connect channels of incompatible voice codec added

#4 Updated by laforge 4 months ago

  • Assignee changed from sysmocom to daniel

#5 Updated by laforge 3 months ago

TS 24.008 states "bearer capabilities" can be present in the following L3 CC messsages:

  • CALL CONFIRMED
    • we parse them in osmo-msc
  • CALL PROCEEDING
    • we encode them in osmo-msc
  • EMERGENCY SETUP
    • we parse them in osmo-msc
  • MODIFY
    • we parse and encode them in osmo-msc
  • MODIFY COMPLETE
    • we parse and encode them in osmo-msc
  • MODIFY REJECT
    • we parse and encode them in osmo-msc
  • ESTABLISHMENT CONFIRMED
  • SETUP
    • we parse and encode them in osmo-msc

In terms of MNCC primitives, any primitive received on MNCC triggering any of the above CC messages should be able to contain bearer capabilities.

#6 Updated by laforge 3 months ago

  • Related to Bug #2933: change of trans->bearer_cap (e.g. via MNCC) will not trigger BSSMAP ASSIGNMENT added

#7 Updated by laforge 3 months ago

  • Status changed from New to In Progress
  • Assignee changed from daniel to laforge
  • % Done changed from 0 to 90

#8 Updated by laforge 3 months ago

  • Status changed from In Progress to Resolved
  • % Done changed from 90 to 100

merged

Also available in: Atom PDF