I was not given all the facts. The customer is using SIP. So when they called from land line (internal phone I found out) back into their site, It worked.
SIP recognized calling party ID and allowed call. When they called in via Cell phone of course the Caller ID stayed when forwarded and SIP blocked call.
I went into the ISDN port serial 0/1/1:23 and put in isdn caller-id of the main site DID and now it works fine. Sorry to bother the Community. I will get my facts straight next time. Thanks for your help and documents.
Configure Multicast Paging on the Cisco IP Phone 7800 Series or 8800 Series Multiplatform Phone
The Cisco IP Phone 7800 and 8800 Series Multiplatform Phones provide voice communication over an Internet Protocol (IP) network...
Add Call Park on a Cisco 7800 or 8800 Series Multiplatform Phone Key Expansion Module
Call park allows the user of the phone to put an incoming call on hold so that the call can be retrieved on another phone. A call is park...