Core Issue
Topology:
Fax server-----ATA---SCCP---CCM----MGCP---3745----PRI-------
Resolution
Instead of an analog telephone adapter (ATA), it is necessary to use a H323 Cisco IOS gateway with a Foreign Exchange Station (FXS) card in order to pass Direct Inward Dial (DID) information as a dual tone multifrequency (DTMF) across the analog port (FXS) to the fax server.
