Dale, the problem here is that the intention of establish INVITE dialog is to send SIP MESSAGE only and there is no media involved. In this case, there is no standard to define media-description in the offer sdp for this purpose. MSRP is encouraged for session-mode message exchanges but I think it is a heavy and complex protocol for exchanges few light-weighted messages. Also, sending page-mode SIP MESSAGE have performance impact on network.
We can very well use SUBSCRIBE but conceptually this will be incorrect for exchanges messages. On Nov 16, 2007 3:55 AM, <[EMAIL PROTECTED]> wrote: > From: "Vikram Chhibber" <[EMAIL PROTECTED]> > > I strongly feel that IETF should define a standard where > media-description is defined to propagate SIP MESSAGE as session-mode. > > Once you've established a dialog, any conforming proxy will propagate > in-dialog MESSAGE requests. The only question is how to establish the > dialog. We've been discussing using INVITE, but it would probably be > better to establish the dialog using SUBSCRIBE. > > In any case, it appears that you must have both the initiating and > terminating UAs understand the use of MESSAGE that you contemplate, so > they can priorly agree on how to set up the dialog. (Is this a place > to use the regretted INFO method?) > > So the only compatibility question is whether a proxy will work > correctly as an intermediate. And as long as you adhere to the rules > for in-dialog requests, you should have no trouble with that. > > Dale > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
