[SIPForum-discussion] Offer-Answer Model

[Retesh]

  and for the callee:

      o  If the UPDATE is being sent before the completion of the INVITE
         transaction, and the initial INVITE contained an offer, the
         UPDATE cannot be sent with an offer unless the callee has
         generated an answer in a reliable provisional response, has
         received a PRACK for that reliable provisional response, has
         not received any requests (PRACK or UPDATE) with offers that it
         has not answered, and has not sent any UPDATE requests
         containing offers that have not been answered.


On 8/27/07, Retesh <retesh.chadha at gmail.com> wrote:
> Hi
> In your scenario, I am assuming that 183 is non-reliable. In that
> case, UPDATE MUST not be sent with a new offer as offer-answer is not
> complete. UAS needs to send the same sdp as in 200 ok.
> Check the following extract from RFC 3311
>
>       o  If the UPDATE is being sent before completion of the initial
>          INVITE transaction, and the initial INVITE contained an offer,
>          the UPDATE can contain an offer if the callee generated an
>          answer in a reliable provisional response, and the caller has
>          received answers to any other offers it sent in either PRACK or
>          UPDATE, and has generated answers for any offers it received in
>          an UPDATE from the callee.
>
>
> --
> With Regards
> Retesh Chadha
>


-- 
With Regards
Retesh Chadha