Hi, >Christer >You are right, of course. Often one realizes certain subtleties only during >detailed implementation and does not see them rightaway on reading the spec. Been there - done that :) >I was simply stating that it is not explicitly stated that the REQ-URI of >the CONTACT in a reliable 1xx be used to send the PRACK. One has to deduce >this from the statement that a CONTACT is mandatory on a reliable 1xx. >Of course, if we do this then the PRACK will bypass the proxy, which is >probably for good (but unstated) reasons that we don't want a stateless >proxy to fork the PRACK, we want the PRACK to be delivered speedily etc. Yes, but if the proxy record route, it will still receive the PRACK. >Further, if we CANCEL the original request, we must not send it to the >Contact, but to the REQ-URI of the original INVITE, right? That is true. There has, however, been a discussion about this on the SIP mailing list. The issue has been if it should be possible to CANCEL specific call-legs. >Also, if the call is setup and a RE-INVITE is issued directly to the >CONTACT, the UAS must not send a different CONTACT in the 1xx. In which 1xx? The 1xx to the RE-INVITE? >If it did, what should the UAC do? Ignore it and continue using the original >CONTACT/terminate the call/ update the CONTACT and direct the PRACK/CANCEL >to the new CONTACT? Strange things may always take place, in very often it's an implementation issue how/if they are handled by the nodes, but the basic rule is to always use the latest CONTACT. After all, it's there for a reason :) Regards, Christer Holmberg Ericsson Finland > > ----- Original Message ----- > From: "Christer Holmberg" <[EMAIL PROTECTED]> > To: "A Venkatraman" <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Friday, July 20, 2001 4:47 PM > Subject: Re: [Sip-implementors] Req-URI of PRACK > > > > > Hi, > > > > Isn't what you say true for ANY request after the INVITE? Ie, if the > > proxy doesn't record route, it will not receive the next request, no > > matter if it is a PRACK, INFO, BYE.... or whatever. > > > > Or, did I missunderstand your question? > > > > Regards, > > > > Christer Holmberg > > Ericsson Finland > > > > > > > > > > > > A Venkatraman wrote: > > > > > > I would like affirmation (or negation+correction) of my understanding of > how > > > the Req-URI is to be built for a PRACK when the proxy does not add a > Record > > > Route. > > > Since the CONTACT is mandatory on a reliable provisional response, the > PRACK > > > must use the CONTACT to build the REQ-URI. > > > This means that the PRACK will bypass the proxies, since none of them > have > > > record routed. > > > A PROXY THAT DOES NOT RECORD ROUTE DOES NOT EVER SEE A PRACK (unless it > is > > > the default outbound local proxy). Correct? > > > > > > The 100rel draft does not specifically mention this, probably because > this > > > is the only obvious conclusion from the statement in the UAS section > about > > > CONTACT being mandatory on the reliable prov response. > > > > > > _______________________________________________ > > > Sipping mailing list http://www.ietf.org/mailman/listinfo/sipping > > > This list is for NEW development of the application of SIP > > > Use [EMAIL PROTECTED] for questions on current sip > > > Use [EMAIL PROTECTED] for new developments of core SIP > > > > > > _______________________________________________ > > > Sip-implementors mailing list > > > [EMAIL PROTECTED] > > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
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