Hi, >>>Is the flows below valid according to recent arguments? >>> >>> UAC UAS >>> |----invite(SDP)--->| >>> |<--- 183(SDP)------| >>> |-----prack(SDP)--->| >>> |<--- 200(SDP)------| >>> >>> flow 1 >>> >>Assuming the 200 is the PRACK response, yes. >>> >>> UAC UAS >>> |----invite-------->| >>> |<--- 183-----------| >>> |-----prack(SDP)--->| >>> |<--- 200(SDP)------| >>> >>> flow 2 >>> >>Not valid. If the INVITE does not contain SDP, a reliable answer must >>contain SDP. We are currently discussing whether the FIRST reliable >>response must contain SDP, or whether that rule can be related. But, >>that is a separate thread. > >Hmm. That flow is a consequence of changing that rule that I had not previously considered. > >Allowing flow 2 would cause all sorts of trouble. If the restriction on offer in first reliable provisional is to be >relaxed it must be sure to state that the first offer must then be in *some* reliable provisional, and until that is sent >there can be no offer sent another way (PRACK or UPDATE). > >Just opening that question is enough to make me more concerned about relaxing the constraint. I am not proposing to allow flow 2, and I don't think relaxing the rule would allow it either. The rule would say that if the INVITE does not contain an SDP offer the SDP offer must be carried in a reliable response. The PRACK can only contain an SDP offer if the UAC has receied an SDP answer. Regards, Christer _______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP
