Registered jack

Uncommon card · No. 160229

A Registered Jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier. After their invention at Bell Labs by 1973, the standard was first defined in the Universal Service Ordering Code (USOC) system of the Bell System in the United States for complying with the registration program for customer-supplied telephone equipment mandated by the Federal Communications Commission (FCC). In 1980, they were codified in title 47 of the Code of Federal Regulations Part 68. The specification includes physical construction, wiring, and signal semantics for numerous connection technologies. Accordingly, registered jacks are primarily named by the letters RJ, followed by two digits that express the type. Additional letter suffixes indicate minor variations. For example, RJ11, RJ14, and RJ25 are the most commonly used interfaces for telephone connections for one-, two-, and three-line...

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