It looks like Section 9 may have forgotten to indicate the behavior when UAC timer support not indicated. Section 8.1 allows a proxy to increase the Session-Expires; I see no reason why the same cannot be done by the UAS.
> -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of Radha krishna > Sent: Tuesday, February 17, 2009 9:48 PM > To: [email protected] > Subject: [Sip-implementors] Sending 422 > > Hi > > Consider the following topology > UA1 ----- Call-stateful-proxy ------ UA2 > > UA1 does not support session timer, Make a call to UA2. Call- > stateful-proxy adds Session-Expires:100 header and forwards to UA2. UA2 > minimum session expires is 900. But in this case INVITE will not contain > "support: timer". According section 9, UAS can reject with 422 only if > there is a timer tag in supported header > > <Snip from RFC> > > If an incoming request contains a Supported header field with a value > 'timer' and a Session Expires header field, the UAS MAY reject the > INVITE request with a 422 (Session Interval Too Small) response if > the session interval in the Session-Expires header field is smaller > than the minimum interval defined by the UAS' local policy. When > sending the 422 response, the UAS MUST include a Min-SE header field > with the value of its minimum interval. This minimum interval MUST > NOT be lower than 90 seconds. > </Snip from RFC> > > Also UAS cannot increase the session expires duration > <Snip from RFC> > The UAS MUST > NOT increase the value of the Session-Expires header field. > </Snip from RFC> > > What should be the behavior of UAS here? > 1) accept the call with 100 seconds? > 2) Increase the duration to 900 seconds while sending 200 Ok? > Note: Session timer should not be turned-off > > Regards > S.Radha krishna > > > > > _______________________________________________ > 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
