[Serusers] How Do I Enable Session Timers On PSTN->SIP Calls?

[Java Rockx]

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