Hi, I was thinking a little more about the offer/answer impact.
And, I am not sure this is an 199 issue after all. The only time a reliable provisional response is currently mandated to carry SDP is the follwing: the INVITE didn't contain SDP offer, in which case the FIRST reliable non-error response (provisional or final) must contain and SDP offer (that is a rule which we have even questioned, but that's another topic). However, 199 will NEVER be the first response sent, since at least one 18x must have been sent prior in order to establish the early dialog. So, unless I have missed something I intend to say a few words about that in the draft and close the open issue. Regards, Christer -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Christer Holmberg Sent: 5. elokuuta 2008 20:31 To: Paul Kyzivat Cc: SIP IETF Subject: Re: [Sip] Comments on draft-ietf-sip-199-00.txt - offer/answerimpact Hi, >>>11) I can't follow the second paragraph of section 9 at all. Can you >>>rephrase it? >>>Once I know what its trying to say, I'll propose alternate text. >> >>What it is supposed to say is that you cannot send a 199 if you are >>required (by the offer/answer rules) to include SDP. > >Thinking about this further... > >This means that a proxy must track the o/a state of the dialog usage in >order to know whether it can send a 199 or not. That could be a >considerable burden. It requires maintaining partial dialog state >rather than simply transaction state, and also requires more parsing of >messages and potentially message bodies. (E.g. with multipart.) > >This has me again questioning the cost/benefit tradeoff of the whole >thing. Of course in this case the cost is to the proxy, and the benefit >is to the UAC. I guess we could simply say never to insert an SDP body in the 199 response. I don't think it would make much harm, since the dialog is terminated in any case. And, this could only happen when/if 199 is sent reliably, since unreliable provisional responses can't carry offer/answers in the first place... Regards, Christer Paul _______________________________________________ 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 _______________________________________________ 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
