The override works on my UCx system. In my SIP trunk configuration, I have an 11 digit NA number (1xxxxxxxxxx). To test the override outbound cid feature, I changed one extension's Outbound CID to a 10 digit number (just xxxxxxxxxx). When I call from the changed extension, the called destination gets the 10 digit caller ID - when I call from any other extension, the destination gets 11 digits.
You can check what Caller ID number is being sent by UCx very easily in the logs. Just make the call, display the last 200 or so lines in the full log and search for the string CDR(outbound_cnum
From my two test calls, I got the following - extension with the override to 10 digits:
Executing [s@macro-outbound-callerid:18] Set("UCX/221@221-0", "CDR(outbound_cnum)=4xxxxxxxxx") in new stack
extension without the override:
Executing [s@macro-outbound-callerid:18] Set("UCX/222@222-0", "CDR(outbound_cnum)=14xxxxxxxxx") in new stack
Also, as you use a SIP trunk, you could enable SIP debugging and look at the SIP INVITE messages. The remote party line for my first call starts with
Remote-Party-ID: "4xxxxxxxxx"
while for the second call it starts with
Remote-Party-ID: "14xxxxxxxxx"
Anyway, from the logs, it's quite obvious that the system uses the override value properly. If you have your system configured correctly, you should see the proper values in the logs. In that case, your SIP trunk provider could be ignoring the Remote-Party-ID value (always uses your trunk's DID or something) - check the provider side configuration or contact your SIP trunk provider support.
