What is T1 Line ?

T-carrier is a generic designator for any of several digitally multiplexed telecommunications carrier systems. T1 seems to mean any data circuit that runs at the original 1.544 Mbit/s line rate. T1 carries 24 pulse-code modulated(PCM), time-division multiplexed(TDM) speech signals each encoded in 64 kbit/s streams, leaving 8 kbit/s of framing information which facilitates the synchronization and demultiplexing at the receiver.T1 is used in North America and Japan.