What type of gateways do you have.
If their H.323 then telnet to the router, run a debug ISDN q931 and look at the incoming call info. You don't need to understand all of it, just the part immediately after the setup message, which should have the caller name.
If you have MGCP then it's a bit more tricky and you'll have to look through the traces in the CCM but essentially you are looking for the same info.
It may be best to do this out of hours, and set your traces to short, say 60 minutes max.
If the name appears on the gateway or in the traces then there's no reason why it shouldn't appear on the phones, but you need to make sure it's there first. What version of CCM?
Paul
