The Registered Jack (RJ) is a connector specifically designed for networking applications. The standard defines only the wiring pattern of the connector, not the geometry or gender. The term ‘Jack’ refers to the female connector even though the standard does not differentiate the gender of the connector. These connectors are also referred to as “modular connectors” as they were helpful in making the telephone network of early days more modular. The RJ standard is primarily defined for the wiring of telephone networks. The connectors following RJ standard wiring pattern are called RJ connector and are available in both male and female types. There is large number of RJ standard connectors available like, RJ11, RJ14, RJ21, RJ45 etc.