CUCM is setup with Translation Pattern of 2228 which redirects to International Number.
When I call 2228 internal same CUCM cluster, the redirection works. When I call from outside but showing my Calling ID, its works. But when I hide my Calling ID to blocked or private and calling from outside the network, the redirection does not work.
Can you take some SIP debugs "debug ccsip mess" and post up the two Invites - the inbound one received from CUCM, and the outbound one to the ITSP? It might be that a SIP profile is needed instead of, or as well as a voice translation rule.