Subject: RE: [Sipping] New version of the early media draft

From: "Francois Audet" <[email-masked]>
Date: Fri, 7 Mar 2003 15:49:47 -0800

> I am confused by the resistance to solving this problem in the
straightforward way. The 
> existance of in-band media seems a perfectly reasonable thing to want to
signal at the 
> SIP layer. People seem quite happy to give the 183 message this semantic,
for the case 
> where the call state is unknown - why is it such a big deal to convey the
*same
> information* at the SIP layer for the case where the call state is known
to be 
> alerting ?? All I want to do is atomically signal the equivalent of 180
*plus* 183.

Maybe the solution would be to define a 184 "Ringing, with in-band media".

Or we can argue for another 2 year... 

I'd prefer this approach to the one using the reason phrase in the 180.

---

From: Gonzalo Camarillo <[email-masked]>
Date: Sat, 08 Mar 2003 11:04:27 +0200

Folks,

I was arguing that any MG will have to implement media arrival detection
anyway, because of the 200 OK-RTP race condition. Therefore, you MG MUST
implement media detection. What do you solve with a SIP provisional
response that tells you that media will be coming? I do not see the
value there. Could somebody explain the gains we get from that approach?

And regarding Mark's comment about placing the functionaloty in the
wrong place, a controller tells (using the media policies developed by
the conferencing design team) the mixer of a conference which
participant's voice should sound louder, which one should be discarded,
etc... you can see this as a media policy issue as well. The MGC sends a
media policy description to the MG:

1) if media comes, play it.

2) until media comes, play ringback tone. 

Gonzalo
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