> Now should UAS send 200 OK response to the UPDATE? Yes.
> If it should, then I feel 200 OK for UPDATE should not > include Session-Expires header as one of the session refresh > request is under process [ though INVITE here is the initial > negotiation message for which it has not received any final > response let me treat it as one of refresh request as it > has requested timer.Any comments on this?] . > > Is 'sending the 200 OK with no session-expires for UPDATE > message' the correct behaviour? Or should it be rejected > with any failure response 4xx-6xx? An outstanding session-expires mechanism should not prevent another from occurring. However there is a potential for race conditions concerning knowing if UPDATE sent/received prior to INVITE 200 response. If following rfc4028's recommendation to keep the same refresher, there is no issue. However if swapping refresher or one deactivating session-expires, there is potential complications related to knowing if the INVITE 200 or UPDATE 200 takes precedence because there can be inconsistency between order sent and received. The race condition is not unique to rfc4028. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
