I have been browsing through the posts and found a few that talk about the originating caller ID not being displayed on calls coming in from the PSTN destined to the IP Phone and then forwarded onwards to another PSTN destination like a mobile phone.
Most of them relate back to a restriction imposed by the telco which prevent sending out a CLID outside the DID range registered to that trunk.
However, in this case the customer has migrated to a CUCM solution and claims that it has stopped working ever since. The previous non Cisco solution displayed the caller id on forwarded calls.
H.323 gateways have been deployed and I have checked that in CUCM the Calling Party Selection is configured with "Originating Number".
For testing, I created translation rules on the gateway to mask CLID on all outbound calls with a number outside the DID range.
In this case the q931 debug showed the call being forwarded with the CLID specified in the translation pattern but on the mobile phone the CLID displayed the first number in the DID range. This tells me that it must have happened on the exchange switch but then the question is how did it work before the customer migrated to CUCM.
Is there any special configuration required to get this working or any flag to be enabled so the ANI is recognized as one that is of a forwarded call?
Or is this a CUCM limitation?
I don't believe it ever worked.
Call telco and ask them "can I send ANI of another subscriber" ?
Make sure you customer is present when they answer.