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Feature #4394

closed

Circuit Switched Data (CSD) Support in osmo-msc

Added by laforge about 4 years ago. Updated 6 months ago.

Status:
Resolved
Priority:
Normal
Assignee:
Category:
-
Target version:
-
Start date:
02/13/2020
Due date:
% Done:

100%

Resolution:
Spec Reference:
Tags:
CSD

Description

The MSC side support for CSD would entail:
  • parsing of the "data" bearer type from 04.08 call control
  • passing it correctly to [external] MNCC
  • handling incoming "data" bearer from MNCC
  • permitting data bearer types in internal MNCC handler
  • encoding the related channel types in the 48.008 A (ASSIGNMENT CMD, ...)
  • instructing the MGW to use RTP PT 120 with "CLEARMODE/8000" SDP

Related issues

Related to OsmoBTS - Feature #1572: Circuit Switched Data (CSD) Support in osmo-btsResolvedfixeria02/23/2016

Actions
Related to OsmoBSC - Feature #4393: Circuit Switched Data (CSD) Support in osmo-bscResolvedosmith02/13/2020

Actions
Related to OsmoMGW - Feature #4395: Circuit Switched Data (CSD) Support in osmo-mgwResolvedosmith02/13/2020

Actions
Related to OsmoMSC - Bug #6110: modem-to-modem data call establishment failureResolvedfixeria07/22/2023

Actions
Related to OsmoMSC - Bug #6152: built-in MNCC: forward the @Low layer compatibility I@ IE to the called subscriberIn Progressjolly08/28/2023

Actions
Actions #1

Updated by laforge about 4 years ago

  • Related to Feature #1572: Circuit Switched Data (CSD) Support in osmo-bts added
Actions #2

Updated by laforge about 4 years ago

  • Related to Feature #4393: Circuit Switched Data (CSD) Support in osmo-bsc added
Actions #3

Updated by laforge about 4 years ago

  • Related to Feature #4395: Circuit Switched Data (CSD) Support in osmo-mgw added
Actions #4

Updated by laforge over 1 year ago

  • Subject changed from Circuit Switched Data (CSD) Support to Circuit Switched Data (CSD) Support in osmo-msc
Actions #5

Updated by laforge about 1 year ago

  • Priority changed from Low to Normal
Actions #7

Updated by laforge 11 months ago

  • Assignee set to osmith
Actions #8

Updated by osmith 10 months ago

  • Status changed from New to In Progress
Actions #9

Updated by osmith 10 months ago

  • Description updated (diff)
Actions #10

Updated by osmith 10 months ago

  • % Done changed from 0 to 30
Actions #11

Updated by osmith 9 months ago

  • % Done changed from 30 to 40

WIP code is in osmith/wip-csd branches of osmo-msc.git and osmo-ttcn3-hacks.git.

Mostly implemented, but still buggy:
  • parsing of the "data" bearer type from 04.08 call control
  • encoding the related channel types in the 48.008 A (ASSIGNMENT CMD, ...)
  • instructing the MGW to use RTP PT 120 with "CLEARMODE/8000" SDP

I plan to fix the bugs that are still in there and then submit the first patches, and look into MNCC next.

Actions #12

Updated by osmith 8 months ago

  • % Done changed from 40 to 60

Patches for initial version with external MNCC:

Initial tests:
Actions #13

Updated by osmith 8 months ago

Extending the tests and fixes for bugs found:
Actions #14

Updated by osmith 8 months ago

Extending tests for MO to use all bearer services:

Not sure how to handle BS21T (300) yet, see code review of: https://gerrit.osmocom.org/c/osmo-msc/+/33591

Actions #15

Updated by osmith 7 months ago

  • % Done changed from 60 to 80

Patches are merged, the internal and external MNCC code is adjusted too. It's mostly complete now and has ttcn-3 tests. I expect that tests with real hardware will show additional bugs.

Actions #16

Updated by fixeria 7 months ago

  • Related to Bug #6110: modem-to-modem data call establishment failure added
Actions #17

Updated by fixeria 7 months ago

I submitted several improvements while working on #6110:

https://gerrit.osmocom.org/c/osmo-msc/+/33913 ran_a_mgcp_codec_from_sc(): cosmetic: remove unneeded breaks [NEW]
https://gerrit.osmocom.org/c/osmo-msc/+/33914 ran_a_mgcp_codec_from_sc(): map GSM0808_SCT_CSD to CODEC_CLEARMODE [NEW]
https://gerrit.osmocom.org/c/osmo-msc/+/33915 ran_a_channel_type_to_speech_codec_list(): set PI/PT for CSD [NEW]

Actions #18

Updated by osmith 7 months ago

  • % Done changed from 80 to 90
Actions #19

Updated by osmith 6 months ago

As discussed, I'm looking into adjusting the handover code for CSD before closing this. It looks like the code doesn't need much of an adjustment, but also a ttcn-3 test I've added doesn't pass yet.

Actions #20

Updated by osmith 6 months ago

Actions #21

Updated by fixeria 6 months ago

  • Related to Bug #6152: built-in MNCC: forward the @Low layer compatibility I@ IE to the called subscriber added
Actions #22

Updated by osmith 6 months ago

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

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