T-1

A frame-based communication protocol that delivers a two-way connection at 1.544 Mbps each way. In Europe and other countries outside the U.S., the near-equivalent of T1 is a service called E1—a two way connection at 2.048 Mbps. T1 and E1 define the physical, electrical and framing requirements of the interface. Therefore the actual transmission media is irrelevant and can be different types of lines such as fiber optic or copper wire.