Nevermind all - I found the answer (thanks Jan) in the archives.
http://lists.iptel.org/pipermail/serusers/2005-March/016484.html
Regards, Paul
On Wed, 23 Mar 2005 21:01:04 -0500, Java Rockx javarockx@gmail.com wrote:
Hi All.
Our PSTN gateway supports Session-Expires for re-INVITEs. The session timer is "automagically" enabled when dialing SIP->PSTN.
However, when calling PSTN->SIP re-INVITEs do not happen, however the PSTN GW does support them.
I think the problem is that PSTN->SIP calls need to (for some reason) explicitly request session timers.
How would I request this? I know I can add the "Session-Expires: 120;refresher=??" header, but do I then do this in the 200OK response back to the PSTN GW?
Also, if the PSTN->SIP call is asking the PSTN GW to enable session timers, would the "refresher=" tag be set to UAS or UAC?
Regards, Paul