This is still not entirely clear to me. What I gathered so far is that a Record-Route header received in a 200 OK updates any route set that might have been established in the early dialog phase. However, I believe that the Record-Route header in different 1xx responses may be different from each other, as a proxy is allowed to re-write (side-note: I guess that excludes removal?) its own entry in the response. Whether it is useful or not is another matter, but I could not find anything in the spec that prevents a proxy from rewriting its own entry in the Record-Route header differently for different responses. And even so, one can never prevent a proxy from not following the spec, so I think it would be useful to more exactly define the behavior.
I could imagine two kinds of behavior: * Build the route set from the Record-Route header received in the response creating the early dialog, not change it until the 200 OK arrives, at which time the route set for the remainder of the dialog is built. Or: * Build the route set from the Record-Route header received in the response creating the early dialog and and rebuild it for any subsequent provisional responses, until the 200 OK is received, at which time again the route set for the remainder of the dialog is built. Or shouldn't it be similar to the SDP in responses (where the initial offer was in the INVITE)? In that case, if I understand it correctly, the SDP in the 200 OK is authoritative, but the UAS MAY include the same SDP in any prior responses. Since the UAC MUST treat the first SDP it receives as the answer, the media is effectively fixed with the first response that contains an SDP, even if the 200 OK (wrongly) contains a different SDP. For the Record-Route and the ensuing route set, this would mean that Record-Route in the response creating the early dialog defines the route set not only for the early dialog, but also for the dialog created by the 200 OK (even though that may possibly contain a differen Record-Route header). This would however deviate from the provision that any headers in a response during an early dialog are only valid during the early dialog. Which one should it be? Regards, Joachim > -----Original Message----- > From: Medhavi Bhatia [mailto:[EMAIL PROTECTED]] > Sent: Thursday, July 25, 2002 3:42 PM > Cc: [EMAIL PROTECTED] > Subject: Re: [Sip-implementors] record-route in 183? > > > I think that argument applies to the non-reliably sent PRs also. > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > To: "Medhavi Bhatia" <[EMAIL PROTECTED]> > Cc: "Aditya" <[EMAIL PROTECTED]>; "Baniel Uri-CUB001" > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Thursday, July 25, 2002 8:50 AM > Subject: Re: [Sip-implementors] record-route in 183? > > > > > > > > > > Hi, > > > > The 200 OK response & any number of reliable provisional > > responses (RPRs) that belong to a particular dialog > > (identified by these particular From and To header tags) > > cannot have different Record-Route headers. > > > > If at all you get a different record-route header set, > > the response would also have a different tag in the To > > header, thereby, creating another dialog. > > > > The UAC needs to keep track of all route-sets for each > > new dialog that results for the initial INVITE and for > > refresh requests for the existing sessions. > > > > Regards, > > Siddharth. > > > > --------------- > > Siddharth Toshniwal @ Hughes Software Systems, > > Bangalore, India. > > > > > > > > > > > > > > "Medhavi Bhatia" <[EMAIL PROTECTED]> on 07/25/2002 06:08:13 PM > > > > To: "Aditya" <[EMAIL PROTECTED]>, "Baniel Uri-CUB001" > > <[EMAIL PROTECTED]>, [EMAIL PROTECTED] > > cc: (bcc: Siddharth J Toshniwal/HSSBLR) > > > > Subject: Re: [Sip-implementors] record-route in 183? > > > > > > > > > > Any headers in provisional responses are valid only for > early dialogs, > > so the 200 ok headers should replace. > > > > However, I dont see how they would be different. The spec does seem > > to be fuzzy in this respect. > > > > ----- Original Message ----- > > From: "Aditya" <[EMAIL PROTECTED]> > > To: "Medhavi Bhatia" <[EMAIL PROTECTED]>; "Baniel Uri-CUB001" > > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > > Sent: Thursday, July 25, 2002 12:48 AM > > Subject: Re: [Sip-implementors] record-route in 183? > > > > > > > > > > Will the UAC override the route Set made with 183 > > > (provisionals) Record Routes with one from 200 OK? > > > > > > If multiple provisionals come will a new route set be > > > made for each provisional at UAC ? > > > > > > -AD > > > > > > --- Medhavi Bhatia <[EMAIL PROTECTED]> wrote: > > > > If the INVITE had the record route, the 183 MUST > > > > have it. > > > > Consider a scenario, where the 183 reaches the UAC, > > > > and > > > > it had a contact in it. If the UAC now wants to send > > > > a BYE, > > > > and there was no record-route in the 183, the BYE > > > > may > > > > bypass any proxies originally intended to be in the > > > > call path. > > > > > > > > ----- Original Message ----- > > > > From: "Baniel Uri-CUB001" <[EMAIL PROTECTED]> > > > > To: <[EMAIL PROTECTED]> > > > > Sent: Wednesday, July 24, 2002 7:48 PM > > > > Subject: [Sip-implementors] record-route in 183? > > > > > > > > > > > > > Is record-route returned in 183? (or only in the > > > > final response that > > > > follows > > > > > such as 200)? > > > > > > > > > > > > > > > > > > ============================================================== > ========= > > > > > Uri Baniel - Distinguished Member of Technical > > > > Staff - Motorola > > > > > Tel: (847) 632 4616; Fax: (847) 632 3963; > > > > > "Learning that does not daily increase will daily > > > > decrease. - EWC > > > > > > > > > > > > > ============================================================== > ========= [...] _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
