Media and Signalling negotiation

Hi All,

First let me dictate the call flow and the nodes involved.

UA1 <--------------> Proxy1 (Kamailio)/RTPProxy1 <-------------------> Asterisk <-------------> Proxy2(Kamailio) /RTPProxy2<---------> UA2

Currently, Asterisk acts as a B2BUA server, and the location lookup/registration is handled by the Proxies. The Asterisk, is in the signalling as well as media (audio) path.

Problem Statement:

  1. Asterisk should be in the audio path and not video path if the call is a audio+video call. So, audio goes from UA1, to RTPproxy, Asterisk to RTPProxy to UA2 and back. While video from UA1 to RTPProxy 1 to RTProxy2 to UA2.


  1. Can Asterisk be configured/programed, so that it negotiates with RTPProxy1/2 video IP/port? While for Audio it does negotiation with its own IP and Port as its currently doing.


No, Asterisk does not operate that way and can’t be configured to do so.

Is there a way to send the RTPProxy1 ip:port to the UA2 in the Invite from Asterisk to UA2 instead of its own.

Or the other option, is the client UA1 sends a re-invite or update message to Asterisk (via Proxy) which contains only video m line and respective parameters, and Asterisk sends its Invite towards Proxy2/UA2 without fiddling with the SDP.

Can anyone help here? Its bit urgent

See on urgency. It seems likely that you have several man weeks of C code development ahead of you if you want to do this with Asterisk.

5 hours ago I was asleep and unconscious. As for your question the answer is still no, Asterisk is a B2BUA and except for limited cases (of which this is not one of them) does not pass such information through.