Your manager requires that users who call PSTN phones from Cisco IP Phones in a Cisco Unified Communications Manager cluster have the single caller ID of 13125551000 for the entire company.
Which approach achieves this goal?
A. Change the external phone number mask on all phones to 13125551000.
B. Create a route pattern in Cisco Unified Communications Manager of 13125551000.
C. Create a VoIP dial peer to Cisco Unified Communications Manager with the destination pattern of 13125551000.
D. Configure the gatekeeper to change the caller number to 13125551000.
