A time-division multiplexed bus which provides 1024 time-slots for transmission of data (almost always voice). The physical connection is a small ribbon cable with multiple edge connectors (usually four). Voice processing cards are connected together on this bus. Software is used to tell each card which timeslots to transmit and receive on.

Using SCbus, voice processing cards can be connected to interface cards such as Voicebridge cards or T1 or ISDN Dialogic interface cards.