I have 3 voice center contain a AVAYA and 2 Asterisk .
AVAYA is connected to Asterisk by sip trunk , then this Asterisk is
connect to another Asterisk by another sip trunk .
I have the certain
dial pattern on each voice center , and I can call from AVAYA to first
Asterisk and can call from each Asterisk together . this is my Plan :
AVAYA ------------------sip trunk---------------- Asterisk 1 ------------------sip trunk---------------- Asterisk 2
AVAYA to Asterisk 1 work fine and Conversely.

Asterisk 1 to Asterisk 2 work fine and Conversely.

but the problem is :
I can't call from AVAYA to Asterisk 2 .

Best Regards.