Definition:
A T-1 is connected between a Class 5 Central Office and Customer Premise Equipment switching system such as a PBX or ACD or data communications system such as a router, Frame Relay Access Device, etc. T-1 is connected or "provisioned" to the customer on 1,544,000 BPS (bits per second) on a twisted-pair four-wire (one pair for sending and the pair for receiving) circuit. T-1 consists is digital transmission of 24 separate full-duplex (simultaneous two-way transmission) channels of 64,000 bits per second each.