What Is The Digital Communications Protocol (DCP)?

The Digital Communications Protocol DCP is ATT's standard for digital transmission of voice and data over ordinary telephone wiring. DCP supports two time-multiplexed 64 Kb/s information channels (I-channels) and an 8 Kb/s signalling channel (S-channel). The DCP protocol consists of a 160 Kb/s 4-wire serial data link that operates full-duplex over distances up to 5000 feet (24 AWG). The DCP connects to the CSM via a General Purpose Port (GPP). The GPP connects the S-channel to the module processors and the 2 I-channels to different time slots for switching.