----- Original message -----
> On 10/10/2010 04:07 PM, Stefan Sayer wrote:
> 
> > 3. At 120 sec in, SEMS sends a reinvite to PBX and gets 200 OK back
> > that contains Session-Expires: 240;refresher=uas.
> > This seems fishy (or I misunderstood the rfc when this was
> > implemented): apparently the pbx tells sems that it now wants the
> > roles swapped, that it wants to be refresher (pbx is uas in this
> > reinvite!)
> 
> I had thought that the 'uas' and 'uac' roles are computed relative to 
> the origin and destination of the original INVITE transaction that 
> opened the dialog/session, irrespectively of who is sending a given 
> reinvite?
If you read 7.4 sixth paragraph in rfc4028 again, you'll see that it is always 
relative to the current request. In fact it is RECOMMENDED that sems adds 
refresher=uac in order to not swap roles (but then it should also add Require: 
timer). Actually, for sst b2b it may be desirable to try to swap roles to have 
the refresh going e2e instead of originated from the middle.
 
> 
> 
> > no; on the pstngw side, it decided to be the refresher and it did the
> > refresh properly (refresh at 126/246).
> > 
> > In fact this looks to me like an issue in the pbx. A workaround might
> > be to add "refresher=uac" to the reinvite sent to the pbx, in which
> > case our beloved pbx might want to not take over the refresher role.
> > Have a look at SessionTimer.cpp, i guess you can spot the function
> > where to add that easily in order to try.
> 
> Hmm.   I see your point.   I will take your suggestion to experiment.
> 
> -- 
> Alex Balashov - Principal
> Evariste Systems LLC
> 1170 Peachtree Street
> 12th Floor, Suite 1200
> Atlanta, GA 30309
> Tel: +1-678-954-0670
> Fax: +1-404-961-1892
> Web: http://www.evaristesys.com/

_______________________________________________
Sems mailing list
[email protected]
http://lists.iptel.org/mailman/listinfo/sems

Reply via email to