General Information – In Case You Are Curious

 

What are the Registered Jack [RJ] Connectors and Standards?

 

The Registered Jack [RJ] standard first applied to wiring telephone lines that were used support wall "jacks" to connect telephones to the telephone lines in homes and businesses. Each particular wiring configuration is set forth as RJnn, where "nn" are two digits that identify the specific wiring standard of the connector.

 

The RJ11, RJ12, RJ13, RJ14, RJ18 and RJ25 standards may use the same RJ25 physical six slot plastic connector with six metal contacts and six conductor female receivers with six metal contacts. Some of these standards leave two or four connector slots unused depending on the cables connected to them. Some versions of these plastic connectors only have metal contacts installed to support the minimum configuration [one or two pairs]. The wiring of the connector slots may vary depending on features and/or applications to which they are connected.

 

The RJ11 standard uses the 6P2C standard to establish a connection for one telephone line.

 

The RJ12, RJ18 and RJ25 standards use the 6P6C wiring standard with 6 wires terminated in the connector.

 

The RJ12 and RJ18 standards are used mainly in business applications. Some applications use six conductor flat cables.

 

Both the RJ13 and RJ14 standards use the 6P4C wiring standard. RJ13 is similar in application to RJ12. An RJ14 connector supports two telephone lines. RJ14 cable assemblies can be substituted for an RJ11 application, but only one telephone line may be operative.

 

The RJ25 standard supports three telephone lines.

 

The RJ45 standard has an eight slot connector and most commonly uses eight conductor round twisted pair Cat5e cables or higher speed Cat6 cables connected to them. The RJ45 standard is largely used to support network wiring, including Ethernet. Some applications use eight conductor flat cables.

 

The RJ9, RJ10 and RJ22 [4P4C or 4P2C] codes are reserved for telephone handsets. They have no official ACTA registered jack code. These special handset plugs are used on modular telephones to connect the handset to the telephone base. These plastic connectors only have four slots and four conductor female receivers or two slots and two conductor female receivers.