[Freeswitch-users] Transcoding iLBC/GSM

[Pete Kelly]

Hi

I am trying to get freeswitch to bridge 2 calls while maintaining iLBC
or GSM for legA, and allowing legB to choose its own codec.

This is because legA is on a low bandwidth connection so allowing
PCMA/PCMU is unwise.

This works fine on a freeswitch install where there is a Sangoma
transcoding card installed, however when I try it on Freeswitch with
no Transcode card, it just responds with a 488.

I read in the docs that iLBC is only transcodable at ptime=30, do you
think this could be the reason the transcode is not happening. The SDP
looks like this from legA:

v=0.
o=- 3529404938 3529404938 IN IP4 10.15.20.104.
s=pjmedia.
c=IN IP4 188.39.51.2.
t=0 0.
m=audio 4213 RTP/AVP 104 3 98 97 99 8 0 96.
a=rtcp:4001.
a=rtpmap:104 iLBC/8000.
a=rtpmap:3 GSM/8000.
a=rtpmap:98 speex/16000.
a=rtpmap:97 speex/8000.
a=rtpmap:99 speex/32000.
a=rtpmap:8 PCMA/8000.
a=rtpmap:0 PCMU/8000.
a=sendrecv.
a=rtpmap:96 telephone-event/8000.
a=fmtp:96 0-15.

Anyone got any ideas/pointers I can look at?

Thanks

Pete