> That essentially means neither UAC nor UAS supports RFC 4028 but P1 and P2 > run the session expiration timers as a result when the timer times out both > P1 and P2 release their calls/ resources.
This is not expected to occur as per RFC 4028. May be you should just elaborate how you think situation occurs if RFC's guidelines are followed. Regards Pandu On Tue, Nov 24, 2009 at 5:24 PM, Dushyant Dhalia <[email protected]> wrote: > ____ _ ______ _____ _____ > | UAC | ______ | P1 | _______ | P2 | _______ | UAS | > |_____| |______| |_____| |_____| > > Consider the above configuration - > > UAC doesn't insert Session-Expires header in Initial INVITE. > RFC 4028 section 8.1 says that "A proxy MAY insert a Session-Expires header > field in the request before forwarding it if none was present in the > request." > P1 inserts Session-Expires header. > P2 receives INVITE with Session-Expires header and forwards it to UAS. > UAS doesn't support Session-Expires so it doen't insert this header in the > response. > The response arrives at P2. Now RFC 4028 section 8.2 says " > > When the final response to the request arrives, it is examined by the > proxy. > > If the response does not contain a Session-Expires header field but > the proxy remembers that it requested a session timer in the request > (by inserting, modifying, or examining and accepting the > Session-Expires header field in the proxied request), this means that > the UAS did not support the session timer. If the proxy remembers > that the UAC did not support the session timer either, the proxy > forwards the response upstream normally. There is no session > expiration for this session. If, however, the proxy remembers that > the UAC did support the session timer, additional processing is > needed. > > Because there is no Session-Expires or Require header field in the > response, the proxy knows that it is the first session-timer-aware > proxy to receive the response. This proxy MUST insert a > Session-Expires header field into the response with the value it > remembered from the forwarded request. It MUST set the value of the > 'refresher' parameter to 'uac'. > > ". > That essentially means neither UAC nor UAS supports RFC 4028 but P1 and P2 > run the session expiration timers as a result when the timer times out both > P1 and P2 release their calls/ resources. In certain cases this could be > potential revenue loss scenario. > > Is it a bug or some gap in understanding? > > Dushyant P S Dhalia > Rancore Technologies, > Gurgaon, INDIA > > -- > "When work is a pleasure, life is a joy! When work is duty, life is > slavery." > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
