On Wed, 2008-12-10 at 15:57 +0200, salvatore loreto wrote: > >> There is also the question of whether we can create the initial dialog > >> without knowing in advance whether another dialog will want to > >> correlate with it. In the call-completion work, we took as an > >> assumption that call originators would not be willing to tag each call > >> with a special value just so that a small minority of calls could > >> later have call-completion applied to them. > >> > [Sal] yes I agree that we have to discuss "when correlation happens", > I do not have a strong opinion on this point, I think the correlation > could happen at any point during the dialog establishment phase. The question is, that is, it might or might not be a requirement: Does a dialog have to be specially marked during its establishment in order for another, later, dialog to correlate with it? > >> But with a little work, we can construct sequences > >> of interactions that cause a UA to create dialogs A and B to different > >> endpoints, and then only later, the UA is forced to conclude that A > >> and B are in the same communication space. But since the UA didn't > >> know that fact at the time it created A and B, it may not have been > >> able to tag them as "in the same communication space". > >> > >> One way to get out of that mess is to make the "in the same space" > >> relationship abstract, and the UA never needs to actually know it. > >> (The "References" header uses this escape; "related" is only truly > >> known by an omniscient observer, and a UA never needs to know whether > >> two dialogs are "related", it only needs to indicate to the omniscient > >> observer that it knows at this moment that two dialogs are "related".) > >> > [Sal] here you are already talking about a solution, where I think we > should still continue to discuss the requirements > and the use case related to the requirements. Actually, I'm talking about another potential requirement: If dialogs A and B are established, with no indication of correlation between them, does it need to be possible for a dialog C to establish a correlation with *both* A and B? (Which will presumably place all 3 dialogs in the same communication space.) Dale _______________________________________________ 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
