[Users] Sometime t_really() func seem to be endless

[Bodin Bruno]

I found a part of problem.
it's a call to a IPBX
When there is an unavailability of number then I get this from IPBX :
503 Service Unavailable

That seem to work correctly. But when I recall a number to this IPBX 
(same or another number ), openser don't try to call IPBX and only send 
it to user :
473 Filtered destination (473/TM)

thank for your light