- A long-distance, point-to-point communications service, providing up to 28 T1 channels.T3 can carry 672 channels of 64Kbps, for a total bandwidth of 44.736Mbps, and is usually available over fiber-optic cable. T3 is used almost exclusively by AT&T and the regional telephone operating companies, although certain large private corporations are using T3 with digital microwave or fiberoptic networks. In Europe, T3 has been superseded by the CCITT DS-3 designation.
Dictionary of networking . 2014.