Issue: The AudioCodes Mediant 1000 (M1K) had PRI circuits terminated on it and was connected to the AudioCodes MP124 (Analog Gateway) via SIP trunk. The Proxy Set and Routing Tables were configured to route inbound DID calls through the M1k and over to the analog gateway.
Resolution: Disable the OPTION messages going to the MP124. What was happening is that the MP wasn't answering the OPTION messages so the M1K didn't think it was alive- which the M1K would use the next rule that matches the number (which in this case was the catch all rule).
After we made the change, calls were getting to the MP124 sucessfully.
You disable the option messages in the Proxy Set configuration page (VoIP, Control Network, Proxy Sets Table, Enable Proxy Keep Alive, Set to Disable).