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

What is E1 line?

In telecommunications, E-carrier system, which is revised and improved version of the earlier American T-carrier technology. This has now been adopted by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T). This is now widely used in almost all countries outside the USA, Canada and Japan. . The line data rate for E1 is 2.048 Mbit/s (full duplex, i.e. 2.048 Mbit/s downstream and 2.048 Mbit/s upstream). Physically E1 is transmitted as 32 timeslots, but one is used for framing and typically one allocated for signalling call setup and tear down.

What is a PRI?

A PRI (Primary Rate Interface) is a telecommunication standard used in the Integrated Services Digital Network or ISDN, for carrying multiple DS0 voice and data transmissions between two physical locations. PRI was developed specifically for industrial or large quantity users. PRI is an industrial ISDN line while the Basic Rate Interface, or BRI, is used to cater to home and small enterprises.

Both Primary Rate Interface and Basic Rate Interface are made up of a number of B channels and D channels. B Channel or the Bearer Channel is used for data transmission, including voice, and D channel is meant for signaling and control.