I believe the use of the term "final" in the first sentence of the quoted text is in fact misleading. The document otherwise seems consistent in that UPDATEs must not be sent (nor received) while a offer-answer exchange is pending (as Sanjay alludes to).
A "final" response is one that is >= 200 in SIP. As far as rules for when SDP is not present in an UPDATE, I don't recall any defined use of UPDATE with some other message body. Regards, Bert Sanjay Sinha wrote: > Sean, > > It's because for an INVITE with offer answer in 18x (with Prack) > completes that initial offer/answer exchange and the UAS can process new > offers in UPDATE. > > Sanjay. > > Sean Riley wrote: > >> The Update method specification (draft-ietf-sip-update-02.txt) says the >> following: >> >> "A UAS that receives an UPDATE before it has generated a final >> response to a >> previous UPDATE or INVITE on the same dialog MUST return a 500 >> response to >> the new UPDATE, and MUST include a Retry-After field with a Retry-After >> header field with a randomly chosen value between 0 and 10 seconds." >> >> This suggests to us that a UAC would not be able issue an Update request >> (and have it processed) before a response to a previously issued >> Invite or >> Re-Invite request was received. However, the same specification >> illustrates >> an Update within an initial Invite for the purposes of early media >> establishment. This appears to us as a contradiction. >> >> We suspect this rule requires clarification. We like to know what the >> rules >> are for nesting Updates within Invites and Re-Invites, including >> considerations for when SDP is included, or not included with the Update >> request. >> >> Thanks, >> Sean R. >> >> >> >> _______________________________________________ >> 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
