>>Anyhow, even when using 100rel I "think" (not 100% sure) that the >>SDP must be included in the 200 OK even if it's just a copy of the >>SDP in a previous provisional response. Hope somebody else could >>confirm this.
Strictly, once the 180 has been PRACKed, the 200 OK must not have SDP. IIRC, there are some scenarios (which I cannot think of right now) where putting the 200 OK in both 180 (w/PRACK) and 200 causes problems. (I think the problem scenarios are forking scenarios or UPDATE scenarios) -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Iñaki Baz Castillo Sent: 11 February 2010 14:45 To: [email protected] Subject: Re: [Sip-implementors] About SDPs received in provisional responses El Jueves, 11 de Febrero de 2010, Saúl Ibarra escribió: > Hi all, > > Today I noticed some behavior in a UA that looked weird to me and as I > couldn't find an explanation on the RFC, hope someone can help me :) > > This UA *only* sends the SDP in the 180 provisional response, the 200 > OK doesn't contain an SDP, and no PRACK is being used. So my question > is if this valid according to the RFC?, also if you could point me to > the place in which is explained I'd really appreciate it. The point here is that the SDP cannot change after a first one has been included by the UAS within a provisional response. If the SDP changes in a new provisional response or a final 200 then such SDP must be ignored (the SDP cannot change within the same early-dialog). However, a UAS should include the SDP in the 200 since the provisional response is not reliable (as you said there is not 100rel requeriment so the UAS accepts an INVITE without "100rel" in Require/Supported header). So the UAS cannot know if the provisional response has been received or not by the UAC. Anyhow, even when using 100rel I "think" (not 100% sure) that the SDP must be included in the 200 OK even if it's just a copy of the SDP in a previous provisional response. Hope somebody else could confirm this. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
