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Feature #4393

closed

Circuit Switched Data (CSD) Support in osmo-bsc

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

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

100%

Spec Reference:
Tags:
CSD

Description

The BSC doesn't have to do much to support CSD:
  • parse the bearer service details from the 48.008 A signaling side (ASSIGNMENT CMD)
  • encode the bearer service details to the 48.058 Abis RSL signaling side (RSL CHAN ACT)
  • instruct the MGW to use RTP payload-type 120 as "CLEARMODE/8000"

Related issues

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

Actions
Related to OsmoMSC - Feature #4394: Circuit Switched Data (CSD) Support in osmo-mscResolvedosmith02/13/2020

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
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 #4394: Circuit Switched Data (CSD) Support in osmo-msc 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-bsc
Actions #5

Updated by laforge about 1 year ago

  • Priority changed from Low to Normal
Actions #7

Updated by osmith about 1 year ago

  • Assignee set to osmith
Actions #8

Updated by osmith about 1 year ago

  • Status changed from New to In Progress
Actions #9

Updated by osmith about 1 year ago

First related patches extend gsm0808_enc/dec_channel_type to support data:

Actions #10

Updated by osmith about 1 year ago

  • % Done changed from 0 to 30
Actions #11

Updated by osmith about 1 year ago

I've done a lot of CSD related adjustments in OsmoBSC and started with the first test. WIP code is in osmo-bsc.git osmith/wip-csd and osmo-ttcn3-hacks.git osmith/wip.

Actions #12

Updated by osmith about 1 year ago

  • % Done changed from 30 to 60

First TTCN-3 test is passing now.

ttcn3: osmo-bsc:
Actions #13

Updated by osmith 12 months ago

  • % Done changed from 60 to 70
Actions #14

Updated by laforge 11 months ago

  • Priority changed from Normal to High
Actions #15

Updated by osmith 11 months ago

More testing and related fixes:

Actions #16

Updated by osmith 11 months ago

  • Status changed from In Progress to Feedback
  • Assignee changed from osmith to laforge
  • % Done changed from 70 to 80

laforge wrote:

The BSC doesn't have to do much to support CSD:
  • parse the bearer service details from the 48.008 A signaling side (ASSIGNMENT CMD)
  • encode the bearer service details to the 48.058 Abis RSL signaling side (RSL CHAN ACT)
  • instruct the MGW to use RTP payload-type 120 as "CLEARMODE/8000"

Implemented.

I think this issue is almost done now.

What I'm not sure about:

I'll start working on the MSC side (#4394).

Actions #17

Updated by laforge 11 months ago

On Thu, Apr 20, 2023 at 10:09:57AM +0000, osmith wrote:

What I'm not sure about:
  • OSmux support: should I implement (and add a proper ttcn3 test) for OSmux + CSD, or is this out-of-scope? (Probably not much code to add, but currently it seems to be not working yet from a quick test.)

out-of-scope. Nobody ever mentioned osmux in this context, so I'm surprised to hear about it.

  • match_non_transp_data_rate() does not take the "allowed radio interface data rate" as well as "asymmetry preference" (3GPP TS 48.008 § 3.2.2.11, oct 5a and 5b) into account. Is this in scope of this issue or not?

For the first part, I don't know off my head. asymmetric rates are clearly not a concern for now.

Actions #18

Updated by fixeria 7 months ago

  • Related to Bug #6110: modem-to-modem data call establishment failure added
Actions #19

Updated by osmith 7 months ago

  • % Done changed from 80 to 90
Actions #20

Updated by osmith 6 months ago

  • Status changed from Feedback to Resolved
  • Assignee changed from laforge to osmith
  • % Done changed from 90 to 100

As just discussed, taking the "allowed radio interface data rate" into account is not required to complete this.

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