[Kamailio-Users] early media and first SIP/Kamailio Configuration

[Daniel-Constantin Mierla]

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 at 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

-- 
Daniel-Constantin Mierla
http://www.asipto.com/