You are right on that, no midway record-route changes definitely! --- Vishal Phirke <[EMAIL PROTECTED]> wrote: > > Ooops... I was thinking of route-set and UAC > > Just to add, there are applications where a proxy would like to be involved > in > the signaling path only till the point of call establishment and later on > leave > to the endpoints for further signaling messages. The last I tested with > VOCAL, > it behaved in the same manner. > Does the UAC actually honor mid-dialog Record-route changes and removes the > proxy from the signalling path in this case? In other words, does vocal > expect UAC to update it's route-set based on mid-dialog record-route > headers. > -Vishal > > > > > > "Hearty, John" > > <[EMAIL PROTECTED]> To: > "Vishal Phirke" <[EMAIL PROTECTED]>, > Sent by: > <[EMAIL PROTECTED]> > <[EMAIL PROTECTED] cc: > > lumbia.edu> Subject: RE: > [Sip-implementors] Record-Route and re-INVITE > > > > > 06/06/2003 11:06 AM > > > > > > > > > > Inline. > > > So if UA receives mid-dialog requests with Record-Route headers then it > > should copy the Record-Route headers in to its 2xx response. Correct me > > if > > I am wrong. > > > > [VP] I believe what John was saying is that it shouldn't copy and just > > ignore the record-route headers received in mid-dialog requests and only > > time it might want to use them is when it is trying to recover from a > > crash. > > No, Meena and Chris had it right, the UAS still needs to copy the R-R into > the 200 OK. Otherwise a crashed UA on the other end would not be able to > rebuild the session. > > > And I guess recovery part is implementation dependent. To recover > > from crash you need lot of other state than just record-route and if you > > are saving such states in some persistent way then why not save > > recrod-route as well. > > The idea is all state is recovered from the message without storing > anything. Some relevant text from 3261: > > 12.2.2 UAS Behavior > > <snip> > > If the request has a tag in the To header field, but the dialog > identifier does not match any existing dialogs, the UAS may have > crashed and restarted, or it may have received a request for a > different (possibly failed) UAS (the UASs can construct the To tags > so that a UAS can identify that the tag was for a UAS for which it is > providing recovery). Another possibility is that the incoming > request has been simply misrouted. Based on the To tag, the UAS MAY > either accept or reject the request. Accepting the request for > acceptable To tags provides robustness, so that dialogs can persist > even through crashes. UAs wishing to support this capability must > take into consideration some issues such as choosing monotonically > increasing CSeq sequence numbers even across reboots, reconstructing > the route set, and accepting out-of-range RTP timestamps and sequence > numbers. > > John Hearty > Level3 > > > > > Since the route sets of the UA are unaltered by the new Record-Route > > headers, they will route future requests according to the initial Route > > set. What if a proxy involved in the Record-Route suddenly decides not > > to record-route the future requests of the dialog? > > > > [VP] What makes you think that proxy might want to get out of the > > signalling path? Proxies use record-route for call monitoring and ideally > > would like to stay in the signalling path till the end of the call. > > > > > > rgds, > > Meena > > ----- Original Message ----- > > From: Chris Boulton > > To: Hearty, John ; Nataraju A.B. ; Christer Holmberg (LMF) ; Natesan > > Kannan ; Annamalai Meenatchy ; [EMAIL PROTECTED] > > Sent: Friday, June 06, 2003 12:27 AM > > Subject: RE: [Sip-implementors] Record-Route and re-INVITE > > > > > > > > Sounds good to me John. > > > > > > > > > > > > Chris. > > > > > > > > > > > > > > > > > > -----Original Message----- > > From: Hearty, John [mailto:[EMAIL PROTECTED] > > Sent: 05 June 2003 17:13 > > To: Nataraju A.B.; Christer Holmberg (LMF); Natesan Kannan; Annamalai > > Meenatchy; [EMAIL PROTECTED] > > Subject: RE: [Sip-implementors] Record-Route and re-INVITE > > > > > > > > > > > > This whole thread sounds confusing. At a high level, the way it works > is > > as follows: > > > > > > > > 1. The UAS in the initial transaction uses Record-Route headers and > > Contact in the Invite to set the Route set. > > 2. The UAC in the initial transaction uses Record-Route headers and > > Contact in the 200 OK to set the Route set. > > 3. In subsequent requests within the dialog, either UA uses it's > route > > set stored from the initial transaction to build Route headers. > It > > does not rebuild the Route set from Record-Route headers in > > subsequent requests, though the Contact is updated if it changes. > > 4. Proxies may Record-Route subsequent requests. This is only for > > robustness in the case a UA crashes and restarts, and is willing > to > > rebuild the session from the mid-dialog request, in which case it > > uses the new Record-Routes. If a proxy decides not to include > > Record-Route in mid-dialog requests, it will not receive future > > requests in this case. > > > > > > > > > > > > John Hearty > > > > > > Level3 > > > > > > -----Original Message----- > > From: Nataraju A.B. [mailto:[EMAIL PROTECTED] > > Sent: Thursday, June 05, 2003 6:27 AM > > To: Christer Holmberg (LMF); 'Natesan Kannan'; 'Annamalai > > Meenatchy'; [EMAIL PROTECTED] > > Subject: Re: [Sip-implementors] Record-Route and re-INVITE > > > > > > > > > > > > > > > > > > Regards, > > -Nataraju A.B. > > May you live as long as you wish and love as long as you live. > > --Robert A. Heinlein Time Enough for Love. (He may have gotten it > > elsewhere.) > > ----- Original Message ----- > > > > > > From: Christer Holmberg (LMF) > > > > > > To: 'Natesan Kannan' ; 'Annamalai Meenatchy' ; > > [EMAIL PROTECTED] > > > > > > Sent: Thursday, June 05, 2003 5:09 PM > > > > > > Subject: RE: [Sip-implementors] Record-Route and re-INVITE > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > A little strange text in 12.2, I think... > > > > > > > > > > > > What is the use of including a mid-session Record-Route header if > > you can't change the route set? I am not saying one should be > able > > to change the route set, but I wonder what the Record-Route > header > > shall be used for... > > > > > > > > > > > > [Nataraju A.B.] > > > > > > " The Record-Route process is designed to work for any > SIP > > request that initiates a dialog. INVITE is the only > such > > request in this specification, but extensions to the > > protocol > > MAY define others. > > " > > > > > > - Only the dialog creating requests will insert the RR header, > > while other requests must not add the RR header.. > > > > > > > > > > > > Regards, > > > > > > > > > > > > Christer Holmberg > > > > > > Ericsson Finland > > -----Original Message----- > > From: Natesan Kannan [mailto:[EMAIL PROTECTED] > > Sent: 5. kes�kuuta 2003 14:39 > > To: Christer Holmberg (LMF); 'Annamalai Meenatchy'; > > [EMAIL PROTECTED] > > Subject: Re: [Sip-implementors] Record-Route and re-INVITE > > > > > > Further to that, the route-set in the dialog never changes even > if > > there is a record-route header in the response (UAS just copies > > this from the request to the response) to a mid-dialog request. > > > > > > > > > > > > "Requests within a dialog MAY contain Record-Route and Contact > > header > > fields. However, these requests do not cause the dialog's > > route > > set > > to be modified, although they may modify the remote target > > URI." > > > > > > -Section 12.2, rfc 3261 > > > > > > > > > > > > -Kannan > > > > > > > > ----- Original Message ----- > > > > > > From: Christer Holmberg (LMF) > > > > > > To: 'Annamalai Meenatchy' ; [EMAIL PROTECTED] > > > > > > Sent: Thursday, June 05, 2003 4:58 PM > > > > > > Subject: RE: [Sip-implementors] Record-Route and re-INVITE > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > There has been discussions about if it is allowed to change the > > route set during a session, but in general the re-INVITE is like > > any other mid-session request, ie if you have a route set you > > include the Route headers... > > > > > > > > > > > > Regards, > > > > > > > > > > > > Christer Holmberg > > > > > > Ericsson Finland > > -----Original Message----- > > From: Annamalai Meenatchy [mailto:[EMAIL PROTECTED] > > Sent: 5. kes�kuuta 2003 13:13 > > To: [EMAIL PROTECTED] > > Subject: [Sip-implementors] Record-Route and re-INVITE > > > > > > Hi, > > > > > > > > > > > > When we send out re-INVITE do we need to include the Route > > headers with it? Does the Record-route header in the re-INVITE > > change/modify the route-set? When we respond to the re-INVITE, > > do we need to include the Record-route header in the 2xx > > messsage? > > > > > > > > > > > > Thanks & Regards, > > Meena > > > > > > > > > > > > _______________________________________________ > > Sip-implementors mailing list > > [EMAIL PROTECTED] > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > > > > > > > > > _______________________________________________ > > Sip-implementors mailing list > > [EMAIL PROTECTED] > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > _______________________________________________ > > Sip-implementors mailing list > > [EMAIL PROTECTED] > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > Sip-implementors mailing list > > [EMAIL PROTECTED] > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > > > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
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