Codec Change on a SIP Call

[cbirckhead]

I have a Verzion SIP trunk, with the default codec set at G.729. For some reason, various calls are sending requests to upscale to G.711. When this happens, the calls were losing audio, and callers were hanging up. Verizon then said to setup my PBX to deny this request, so I took G.711 away from the network region the SIP trunk is in.

Now when this happens, the call drops completely. The verzion SBC shows that the PBX is still accepting the codec change.

Is there some setting I'm missing? How can I deny a codec change request like this?? The Codec is not available in the network region.. I'm stumped where else to even look.

Thanks!

[alrobert]

I think that I would first verify that you are sending only g729 in the 200 OK from the initial invite. I use tshark in command line the SES to do this, then filter on vip calls under statistics of the wireshark app, then select one that fails. There is only one place that I know of that you set up the codec sets - in the network region. Make sure that your ip-codec-set only has g729 in it. Also there are differant variations of g729, g729, g729a, g729b you may be sending a flavor they do not use. Also make sure you are up to current or at least nearly so (within 2 releases) for firmware release on the prowler/crossfire, we had issues for a while on older releases.

[cbirckhead]

Thanks.. this looks like a known issue in CM 5.2 that is being addressed in SP4 which is due for release today, if anyone is having the same problem here's the PSN:

http://support.avaya.com/css/P8/documents/100090096

[mynameis]

thanks for posting the link I love avaya phone systems