To debug ISDN for CLID, you can login via SSH, execute "asterisk -vvvvr" to enter Asterisk, then execute "pri set debug 2 span X" to enable debug on ISDN ( X is the span number, you can execute "pri show spans" to check all spans ).

When you make or receive calls, you can copy the logs out and then research "setup", the CID and DID are in the message of "setup".