I have further queries on re-INVITE without SDP, If this is a query mechanism where the UAS returns the session parameters of existing dialog in 200 OK, what should go in the ACK sent for this 200 OK? Is empty ACK valid here or or the UAC MUST return its session parameters in the request?
Again, if this is a query mechanism, can I assume the "o" line does not change in the SDP of 200 OK or do I need to be prepared for re-negotiation? In my opinion, re-negotiation does not makes sense here as the UAC sends the offer and does not instructs UAS to initiate offer-answer. Thanks in advance, ~Vikram On 9/12/07, Vikram Chhibber <[EMAIL PROTECTED]> wrote: > Thanks everyone. I missed out section "8 Modifying the Session" of RFC 3264 > > On 9/12/07, Retesh <[EMAIL PROTECTED]> wrote: > > Comments inline > > > > On 9/12/07, Vikram Chhibber <[EMAIL PROTECTED]> wrote: > > > Hi, > > > > > > i have few queries on SIP offer/answer for which I couldn't find a > > > straightforward answers: > > > > > > 1. We all are aware that we should be prepared to receive initial > > > INVITE with no offer. In this case, the UAS is supposed to send its > > > offer in the 200 Ok response. > > > Is sending re-INVITE with no SDP valid case? I know sending UPDATE > > > with no SDP is valid. > > > > > Yes, it is a valid case. > > > > > 2. Once a unicast session is established, can any of the party send a > > > new offer with entirely new "o" line?. The motivation for asking this > > > question is that suppose I have a B2BUA who doesn't do much on SDP > > > part and simply copies SDP from incoming messages to the outgoing > > > messages. Now if this B2BUA wants to send re-INVITE (for hold or > > > inactive media) to either party, does it needs to remember previous > > > SDP negiotiation and modifies that SDP to send re-INVITE or can it > > > create a SDP without considering anything form previous offer/answer. > > The session id in the o line cannot be changed within a session. > > > > > > > > Thanks, > > > ~Vikram > > > _______________________________________________ > > > Sip-implementors mailing list > > > [email protected] > > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > > > > > > > -- > > With Regards > > Retesh Chadha > > > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
