On Jun 6, 2008, at 12:45 AM, atul garg wrote: > Hello, > > I have two queries - > > 1) When we say there is a SIP Conference ie more than two parties > are in one call session then how call-id are maintained that is Call > -id remains same or changes ,more precisely if SIP Client-A want to > invite Client-B and C for call ,it sends a SIP INvite to SIP server- > A and ask it to call B and C. Now when SIP server will send two > Invites ,one to B and second to c will all these Call IDs be > different or same. > > 2) Same is for Push To Talk(PTT) , when there is a chat session > established between multiple clients , are the Call id s same or > different or else how one can correlate different messages belong to > one session ?/ is there any session id or some other unique field > present ?? > > Please also suggest if anyone have some study documnt regarding this. >
Most SIP "conferences" are implemented by conference bridges, which are back-to-back user agents. What do they do with call IDs? Whatever they want to -- there behavior really isn't specified by IETF. usually, each "leg" of the bridge will be a separate call with a distinct call ID. This makes life much easier. As I understand OMA POC, this is what happens there -- but you'd have to read their spec to be sure. Each "POC controller" (they call it a "participating function", IIRC) is basically a B2BUA. So even a minimal 2 party POC call has three different call legs, all of which probably have (or at least probably should have) different call-IDs. -- Dean _______________________________________________ Sip mailing list https://www.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
