Yes Agree, The FAQ creation afford would be appreciated and this will reduce exploration through threads which can be like debate than conclusion and in fact this is quite natural.
Also I would be thankful if we maintain "agreed upon" things which are not cited in RFCs to ascertain the unanimity of all UACs/UASs implementation. Thanks, Bhavik -----Original Message----- From: Paul Kyzivat [mailto:[EMAIL PROTECTED] Sent: Thursday, May 19, 2005 7:10 PM To: Chauhan Bhavik-A20762 Cc: sip@ietf.org; sip-implementors@cs.columbia.edu Subject: Re: [Sip-implementors] UPDATE with ANSWER? We really need to create an FAQ about this. A long time ago, probably in the thread you cite, we debated this extensively. It is true that the RFCs are not entirely clear on this, and reasonable people can differ in interpretation of them. But we finally came to some agreement on it. I am quite sure we agreed that UPDATE could *not* be used to send an answer. We ended up with a quite restrictive list of cases for how INVITE, UPDATE, PRACK, and their responses and ACK can be used to convey offer/answer. I was one who originally argued for fewer restrictions. But there were issues with that, and the restrictive approach won out. In practice I don't think the restrictions impose any great burden. Paul Chauhan Bhavik-A20762 wrote: > Hi all, > > I was exploring the possibility for the UPDATE to send the Answer, As > I haven't found any explicit restriction in RFC 3311. > > I went through the older Thread > http://lists.cs.columbia.edu/pipermail/sip-implementors/2004-January/0 > 06017. > html > <http://lists.cs.columbia.edu/pipermail/sip-implementors/2004-January/006017 > .html> > and came across following Qs which I found not clarified though. > > 1. Can UPDATE be used to send an answer SDP ? > Consider the following scenario: > - INVITE was sent without SDP > - 18x is received with Offer SDP > - There is no PRACK exchange because 18x does not contain a > Require:100rel header > Now can UPDATE be used to send answer SDP?? > > 2. As per RFC 3311, UPDATE method should be used only if dialog is > established. > If INVITE/18x exchange happened without PRACK, can both ends treat > this as early dialog and feel free to use UPDATE ? > > 3. Is 18x send/recv over TCP considered reliable ? > In the following scenario: > - INVITE with offer sdp sent > - 18x over TCP with answer sdp recvd (No PRACK exchange happened) > Now can the caller/calleee use UPDATE ? > > Can any body clarify the same? > > Thanks in advance, > Bhavik Chauhan > > _______________________________________________ > Sip-implementors mailing list Sip-implementors@cs.columbia.edu > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list Sip-implementors@cs.columbia.edu http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
