Digital Signal 1
TELEPHONE TRANSMISSION CARRIER SYSTEM IN USA AND CANADA
T1 line; Digital signal 1; T1/E1; T1/PRI; T-span; Yellow alarm; Blue alarm; T1(Networking); DS1C; T1 circuit
Digital Signal 1 (DS1, sometimes DS-1) is a T-carrier signaling scheme devised by Bell Labs. DS1 is the primary digital telephone standard used in the United States, Canada and Japan and is able to transmit up to 24 multiplexed voice and data calls over telephone lines.