[Freeswitch-dev] sending custom SDP in 183 Session Progress

Michael Jerris mike at jerris.com
Tue Nov 23 06:25:35 PST 2010

make sure to set the flags on your application to say it supports no media, you should find some examples in mod_dptools.  Then you can set channel vars for either codecs, or the entire sdp string before calling switch_channel_pre_answer.


> I have a similar problem to the one posted above, which I got by
> searching the archieves:
> http://lists.freeswitch.org/pipermail/freeswitch-dev/2010-May/003653.html
> We have integrated our own IVR with FS. Our IVR handles all media
> (RTP) directly and FS handles only SIP.
> When a call comes to FS with INVITE, in response we send 183 Session
> Progress with FS generated SDP (and RTP IP and port). In 200 OK, FS
> sends SDP with our application generated RTP IP and port. This works
> in most cases.
> Is there any way to invoke my application before sending 183 Session
> Progress, so that our application generated SDP can be sent in the 183
> Session Progress?

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