On 05/14/2009 05:23 PM, Stefan Sayer wrote:
o Daniel-Constantin Mierla [05/14/09 14:43]:
Hello,
On 05/14/2009 12:06 PM, Stefan Sayer wrote:
Hello, o bahanfar@hotmail.de [05/13/09 11:23]:
Hi,
I am newcomer in SIP and Kamailio Wold an have a question.
I have two IP Telefones and would like to realize with Kamailio an IP Communication. The Problem:
a. The UA 1 calls UA 2 b. UA 2 start recording the video form UA 1, before a SIP call is established (early media)
early media is the other way round, from UA 2 to UA 1. UA 1 starts sending media (audio, video, whatever) when it receives 200 OK with SDP answer from UA1 - before it could not possibly know where to send media to, what codec etc.
183 reply usually has the sdp of callee, therefore the caller can send rtp. Or am I missing something?
can, but does usually not do.
I have seen most of 183 with sdp, maybe is just me ... as opposite to 180 ringing, 183 session in progress has sdp.
It also does not make sense to not setup the session, if you do want to have the session.
One usage case can be playing a message and letting caller to agree via dtmf/ivr before forwarding the call to destination. If does not agree and call is cancelled, there won't be any cdr reported to caller.
Cheers, Daniel