see comments inline > > Hi All, > > I have few queries about Session Timer mechanism (RFC 4028), please > clarify it. > Thanks in advance. > > 1) If in the initial session establishment (INVITE 200 OK ACK), there > was no session timer info got exchanged and both the end points (User > Agents) supports Session Timer. > > If Session-Expires header is present in Re-INVITE/UPDATE message, what will > be the behaviour of User Agent ?? > A) Allow to negotiate B) Ignore it > > >> Allowing User Agent to negotiate session interval, looks like ok. > Is there is any rela time scenario ?? The last paragraph of section 7.2 of RFC 4028 basically states that any INVITE/UPDATE request received after a dialog has been established AND contains the Session-Expires header must be processed according to the procedures of the RFC. So in that case the session timer mechanism will be negotiated. > > > 2) If support for Session Timer (ST) is not enabled at User Agent (UA) and > User Agent (UA) sends INVITE with Support header with value as 'timer' to > other end point. > And end point responds with 2xx response with Require header with value > 'timer'. > > What User Agent (UA) should do ?? > a) send ACK, followed by BYE request > b) Let application to decide > c) ignore it and establish call > > i) If refresher parameter in Session Header is set to uas > a) Let application to decide > b) send CANCEL request > c) send ACK, followed by BYE request > d) ignore it and establish call > > ii) If refresher parameter is set to uac > a) send ACK, followed by BYE request > b) ignore it and establish call > c) Let application to decide > As Harsha has already said, this is incorrect - a UA which will not make use of Session Timers should not put a "Supported: timer" header in the INVITE in the first place.
However, did you mean what would happen in the scenario where the UA sends in an INVITE with the "Supported: timer" but minus the Session-Expires header? i.e. The UA does support the session timer mechanism but does not wish to initiate it's use itself? Regards, Steve. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
