Pass SDP transparently


#1

Hi all,

I have a non-trivial requirement.
Setup: Asterisk 13.21, two PJSIP endpoints are created (A and B) with direct media enabled for both.
I would like Asterisk to pass codec parameters transparently between incoming SDP from endpoint A and outgoing SDP to endpoint B.
It is important to note that all the codecs announced by A are supported in passthough mode according to this link.

The explicit need for transparent SDP processing is caused by special parameters in video capabilities which are understood by both endpoints but might not be familiar to Asterisk.
Here is the sample excerpt:

a=rtpmap:98 H264/90000
a=fmtp:98 packetization-mode=1;profile-level-id=64001F
a=rtpmap:97 H263-2000/90000
a=fmtp:97 SQCIF=1;QCIF=1;CIF=1;CIF4=1;CIF16=1;CUSTOM=320,240,1;CUSTOM=640,480,1;CUSTOM=800,600,1;CUSTOM=1280,720,1;CUSTOM=1920,1080,1
a=rtpmap:96 H263-1998/90000
a=fmtp:96 SQCIF=1;QCIF=1;CIF=1;CIF4=1;CIF16=1;CUSTOM=320,240,1;CUSTOM=640,480,1;CUSTOM=800,600,1;CUSTOM=1280,720,1;CUSTOM=1920,1080,1

Is there any way to meet the above requirement by means of Asterisk configuration?
Thank you.


#2

Asterisk does not support this, it would require core modifications and specialized code to do so.