We've recently been discussing on-list the relationship between SIP, MEDICATRL, and possible architectural decisions about the extensibility model for SIP that probably should have been made long ago but weren't.
Following a call today with the SIP, SIPPING, and MEDIACTRL chairs and AD Cullen Jennings, I have a proposal I'd like to make. SIP needs to make some decisions about the extensibility model. I personally suspect we're going to find we have a cases where new SIP request types are needed, cases where new SIP header fields and values are needed, cases where we need to use events, cases where we need to use INFO, and cases where we need to convey stuff in a negotiated session using some sort of session/transport protocol. And we're going to need to give clear guidance about differentiating those cases to the developers of future specifications. If we come to this agreement, then we're going to have a second question related to the session/transport protocol. Do we always use application-specific protocols (MSRP, MEDIACTRL control channel, etc.) or do we gain value by offering a multipurpose session/transport protocol that leverages SIP's negotiation mechanism (like TOTE). I expect that it will take a while to reach consensus here, and that if we decide to pursue a multipurpose session/transport protocol that the work of specifying it will be outside of the SIP working group. We might have a responsibility to feed in requirements and clear architectural guidance. Given that this will probably take more than a meeting cycle or two, and that none of us can see any way that MEDIACTRL as currently specified would "break" any of the potential future directions (after all, we can already negotiate lots of different session types), I see no reason to block MEDIACTRL from proceeding. Further, our assigned expert reviewer, Paul Kyzivat, found nothing in MEDIACTRL that raised an issue (outside of the architectural principles for SIP) that required consideration in the SIP working group. Once we get our house in order, and if we decide to recommend a multipurpose session/transport protocol approach and somebody has specified it, then I can see a future version of MEDIACTRL possibly running on that protocol. What do you folks think? -- Dean Willis SIP co-chair _______________________________________________ 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
