I have an integration with a PBX using CCM6.1. DID's for the Cisco phones are routed from the PSTN, to the PBX, and across this integration. Calls from PBX phones are also routed across this integration. I want to prefix '21' on the CLID only if the CLID is a 4 digit number from another PBX phone and not from the PSTN. The issue here is I could globally do this for all 'Subscriber' calls and be done but I need to integrate with multiple PBX's and each integration would have to prefix a different 2-digit number to the a PBX call.
Is the only way for me to do this is with a H323 gateway and translation on there?