A fractional T1 or T3 line is a T1 or T3 digital phone line in the North American T-carrier system that is leased to a customer at a fraction of its data-carrying capacity and at a correspondingly lower cost. A T1 line contains 24 channels, each with a data transfer capacity of 64 Kbps. The customer can rent some number of the 24 channels. The transmission method and speed of transfer remain the same. Overhead bits and framing are still used, but the unrented channels simply contain no data.
T3 lines (which offer 672 64 Kbps channels) are also sometimes offered as a fractional service. T1 and fractional T1 service are sometimes advertised as "point-to-point" service (from the customer to the service provider).Content Continues Below