> -----Original Message----- > From: Sumit Garg [mailto:[EMAIL PROTECTED] > Sent: Friday, October 12, 2007 2:20 PM > To: Brian Stucker; Dean Willis; DRAGE, Keith (Keith) > Cc: IETF SIP List; Francois Audet; Christer Holmberg > Subject: RE: What are we arguing about when we say INFO? (was Re: [Sip] > INFO) > > Agreed. > > Basically there can be 3 scenario: > > 1. A---------------C (the signaling and media path ) --->2833 is best. > > 2. A---------------B (the signaling and media path ) > C which is a proxy, and in neither path needs the DTMF > (SUBSCRIBE/NOTIFY is best) > > 3. A---------------C------------B (signaling path) > A--------------------B (media path) > C needs the DTMF events, cannot use 2833 and SUBSCRIBE/NOTIFY is okay > but not necessarily the best approach due to the overhead of additional > dialogs (whose duration is tightly linked to the INVITE dialog). INFO > definitely looks attractive here. > > Similarly, the recent draft on rtcp-summary defines a complex > SUBCRIBE/NOTIFY mechanism, which again covers all scenarios gracefully. > However, for scenario 1 and 3 some other mechanism would be better.
Even for scenario 2. In scenario 2 such a proxy was in the path for at least the Invite, in order to know about the session. So even if it wasn't record-routing it may be better for proxy C to do subscribe/notify, but for A and B it will be worse, as they now have an additional dialog... for each proxy C in the Invite's path that wants the information. And if A or B are gateways or servers handling lots of sessions, that's a difference. -hadriel _______________________________________________ Sip mailing list https://www1.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
