Circuit (telecom)

A telecommunication circuit is any line, conductor, or other conduit by which information is transmitted.

A dedicated circuit, private circuit, or leased line is a line that is dedicated to only one use. Originally, this was analog, and was often used by radio stations as a studio/transmitter link (STL) or remote pickup unit (RPU) for their audio, sometimes as a backup to other means. Later lines were digital, and used for private corporate data networks.

The opposite of a dedicated circuit is a switched circuit, which can be connected to different paths. A POTS or ISDN telephone line is a switched circuit, because it can connect to any other telephone number.

On digital lines, a virtual circuit can be created to serve either purpose, while sharing a single physical circuit.

A telecommunication circuit may be defined as follows:

 This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C" (in support of MIL-STD-188).

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