Project

General

Profile

Feature #1846

Implement AoverIP specific procedures, message extensions and information elements

Added by laforge 4 months ago. Updated about 5 hours ago.

Status:
In Progress
Priority:
Normal
Assignee:
Category:
-
Start date:
11/18/2016
Due date:
% Done:

10%

Resolution:
Spec Reference:

Description

AoIP introduces a variety of new RSL information elements that extend the classic BSS[M]AP messages in several ways, for example to carry RTP IP/port identification rather than TDM circuit identifier codes. Or to indicate MSC/BSC codec capabilities.

We'll need to implement those new information elements (parsing/encoding/testcases) and implement their handling in osmo-bsc (and most likely osmo-msc, too)

notes.txt Magnifier (11.6 KB) dexter, 03/21/2017 10:40 PM

messages_we_use.txt Magnifier (6.5 KB) dexter, 03/24/2017 06:28 PM

History

#1 Updated by laforge 4 months ago

#2 Updated by neels 28 days ago

  • Description updated (diff)

#3 Updated by laforge 14 days ago

  • Assignee set to dexter

#4 Updated by laforge 4 days ago

Background info on 3GPP AoIP

#5 Updated by dexter 3 days ago

  • File notes.txtMagnifier added
  • Status changed from New to In Progress

I have reviewed the change requests and created an overview to point out where messages had changed. See the attached file. Each line marked with a # indicates that there is a change that directly affects the message type (by adding/changing codings or adding elements).

#6 Updated by dexter 1 day ago

I have now reviewed the source code. When I get things correct, the following messages types have to be updated:

+ASSIGNMENT REQUEST        (BSS_MAP_MSG_ASSIGMENT_RQST, rx only, osmo_bsc_bssap.c)
+ASSIGNMENT COMPLETE        (BSS_MAP_MSG_ASSIGMENT_COMPLETE, gsm0808_create_assignment_completed())        test exists
+ASSIGNMENT FAILURE        (BSS_MAP_MSG_ASSIGMENT_FAILURE, gsm0808_create_assignment_failure())        test exists
 CLEAR COMMAND
 CLEAR COMPLETE
 CLEAR REQUEST
 RESET
 RESET ACK
 PAGING
 CLASSMARK UPDATE
 CIPHER MODE COMMAND
 CIPHER MODE COMPLETE
 CIPHER MODE REJECT
+COMPLETE LAYER 3 INFORMATION    (BSS_MAP_MSG_COMPLETE_LAYER_3, gsm0808_create_layer3())                test exists
 SAPI "N" REJECT

(+ means, message needs to be patched)

#7 Updated by dexter about 5 hours ago

We have now an encoder / decoder plus tests for "AoIP Transport Layer Address" and an encoder for "Speech Codec Element". (see also libosmocore.git pmaier/aoip)

When I get the osmo-bsc / libosmocore code and the spec right. Then we only need the following additional fields for the BSC case:
AoIP Transport Layer Address (MGW)
Codec List (MSC Preferred)
Call Identifier

Judging by the messages osmo-bsc can unsterstand, we would need generator functions for the following messages:
BSS_MAP_MSG_PAGING
BSS_MAP_MSG_CIPHER_MODE_CMD
BSS_MAP_MSG_ASSIGMENT_RQST

(I have attached some of my notes with some more details about what is missing)

Also available in: Atom PDF