I'm currently doing some testing with Asterisk ( 1.8.11.0) on RHEL6 using realtime for sippeers, sipusers and musiconhold I have Avaya definity <-> PRI E1 <-> Asterisk 1 <-> IAX2 <-> Asterisk 2 I have peers (sip) snom 821s on both Asterisk 1 and 2 all calls working between all systems. CallerID from Asterisk to Avaya is working correctly. The problem is a caller from Avaya to Asterisk displays correctly the CID of the Asterisk Extension to the calling party on the Avaya but only if the peer is on Asterisk 1. If the peer is on Asterisk 2 only the CID of the PRI on the avaya side is displayed. I hope this makes sense. I'm not sure where to start looking or whether its even possible. I can of course supply any of the configs that may help. Cheers Stephen Collier