Hi, At least in RELIABLE provisinal responses Contact is required, in order to be able to send PRACK.
One of the issues we've been discussing before is whether an UAC is allowed to send a non-CANCEL mid-dialog request once it has received an UNRELIABLE provisional response. I think the conclusion has been that it IS allowed, and in that case a Contact of course would be needed. Whether we want to mandate Contact in unreliable provisional responses or not is one issue, but as part of the new fix-the-bugs-in-3261 work item it would give us an opportunity to clarify the issue. Another, related, question which comes up every now and then: IF I receive a provisonal response with a Contact, is it allowed to "update" that Contact in the 200 OK (or, another reliable resonse)? Whatever the answer is, I think some clarification text would be useful. Regards, Christer > -----Original Message----- > From: Jeroen van Bemmel [mailto:[EMAIL PROTECTED] > Sent: 26. toukokuuta 2007 13:52 > To: [email protected]; [EMAIL PROTECTED] > Subject: Re: [Sip] Contact header in 1xx responses/updates > remote target ornot? > > Dale, > > Not sure if I read your comment right, but RFC3261 12.2.1.2 says > > When a UAC receives a 2xx response to a target refresh request, it > MUST replace the dialog's remote target URI with the URI from the > Contact header field in that response, if present. > It does not say anything about 1xx responses here > though...Regards,Jeroen [EMAIL PROTECTED] wrote: > > From: Nina Garaca <[EMAIL PROTECTED]> > > > > Q1: Should I expect that these responses have a Contact header? > > > > As Paul says, if it didn't have a Contact header, it couldn't > > establish a dialog. > > > > Q2: If they do so, should the remote target of the dialog be > > refreshed by that Contact at the side that has received that 1xx > > response and should the remote target of the dialog be > refreshed by > > the Contact in the INVITE request at the side that has > received that > > INVITE? > > > > Responses are not "target refresh requests", so they don't > change the > > target address at their end of the dialog. But of course, the > > responses to the dialog-initiating request establish the initial > > target address. > > > > Q3: If not, should the remote target of the dialog be refreshed by > > the Contact in the INVITE request > > at the side that has received that INVITE and has sent dialog > > establishing 1xx response? > > > > RFC 3261 section 12.2: > > > > INVITE, the only target refresh request defined is re-INVITE (see > > Section 14). Other extensions may define different target refresh > > requests for dialogs established in other ways. > > > > Dale > > > > > > _______________________________________________ > > 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 > > > _______________________________________________ > 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 > _______________________________________________ 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
