What Is the Speed of a T1 Line?

One of the first telecommunications backbones the DS-1 or Digital Signal 1 line, often referred to as a T1 line, is a communications carrier used in America and Japan to transmit voice and later data. Devised by Bell Labs in the late 1950s it is one of the oldest telecommunications protocols in use.

Size

The T1 line is made up of twenty-four 8-bit channels capable of 64 kbit/s of bandwidth each giving a total concurrent bandwidth of 1.544 Mbit/s.

Benefits

T1 lines decreased the costs of carrying voice and data over large distances by removing the need for costly modulators and demodulators.

Function

Originally the T1 carrier operated as the backbone of voice communications for all of Bells Labs' customers. Later however, the T1 would become the backbone for data connectivity due to the phone networks already extensive existing network.

Misconceptions

T1 refers to the actual physical line over which the data is transferred, whereas the logical bit pattern used to transmit the data is named DS-1. Though the terms are often used interchangeably they are two different things.

Significance

With the reduced cost accompanied by the advent of the T1 line it became easier for the telephone to make its way into every household in America. It later also aided as a cheap readily available network to serve as the backbone of the Internet.

Resources

• All You Wanted to Know About T1 But Were Afraid to Ask