> -----Original Message----- > From: Michael Procter [mailto:[EMAIL PROTECTED] > Sent: Thursday, October 18, 2007 5:33 AM > To: Dean Willis; Hadriel Kaplan > Cc: sip; Paul Kyzivat; Brian Stucker; Francois Audet; Christer Holmberg > Subject: RE: [Sip] INFO > > Dean Willis wrote: > > The only argument I can see is -- it prevents race conditions. Don't > > send an event until the ACK. > > That sounds like the media clipping problem. If the INVITE indicates > willingness to receive a specific event, then maybe it should be able to > do so before it has seen the 200 response. Then the UAS needn't wait > for the ACK before sending events.
Actually, I think it the other way - if there were no such thing as media before 200ok/ACK, there wouldn't be an early media problem. So I think the INFO needs to wait for the ACK period, like BYE's do. > > > And I'm still stuck on your last question, which is what > > > application use-case really needs directionality, other than as a > > nit? > > > > Yeah, me too. Or to rephrase, what application needs "I want to > > send . . ." rather than "I understand . . ." > > DTMF? I noticed this problem with RFC2833 negotiation a couple of years > ago. A device wanted to indicate willingness to send RFC2833, but > wasn't able to render received indications. Since SDP describes what > the device can receive, the 'solution' was to fib. Yeah, that was my first response to Dean's question (that DTMF has such a use-case), but "fibbing" about it isn't really harmful. You may get extraneous INFO, which you just don't render. (just like for 2833) The question is if the extra complexity of directionality is worth it or not, and is it necessary to provide in the general negotiation vs. in individual event packages. In other words, if some event package got defined which really needed directionality, it could handle that itself with two event names. But if it would be a common problem it's better for the general solution to handle it, IMO. -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
