> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:sip- > [EMAIL PROTECTED] On Behalf Of Alex Balashov > Sent: Friday, November 28, 2008 7:34 PM > > The problem is that 183+SDP is not an "ordinary" provisional response > because it has the potential to enact media flow, not just provide an > indication of a far-end action and/or establish a formal early dialog.
180 has SDP sometimes too - in fact any provisional response can have SDP; and since any provisional you don't understand you should handle as a 183, it *is* ordinary and gotta be handled right. > It's just that I wonder how this > would be viewed differently if no B2BUA were involved and the > originating UAC simply called through a forking proxy that sent it back > two 183s with different SDP information. I would think that the rule > would be to capture the SDP offer in the first 183 as the winner and > ignore the other one, so presumably it is reasonable for the B2BUA to do > the same on the sending UAC's behalf. No, there's no real rule for that UAC behavior AFAIK. Though I think it's common practice for UAC's to only render RTP from the first SDP until 200ok. For B2BUA's, some only send back the first 18x w/SDP, others make separate early dialogs on their UAS side and send each back with unique to-tags. The B2BUA is basically broken if it sends them all back with the same to-tag but unique SDP, IMO. -hadriel _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
