Difference Between RJ11 and RJ14 and RJ25 and RJ12 in Structured Cabling

RJ11 vs RJ14 vs RJ25 vs RJ12 in Structured Cabling

RJ 11 and RJ12 are two different standards in structured cabling. RJ11 is 6P4C type of wiring and RJ12 is 6P6C wiring standard. RJ is acronym to Registered Jack. RJ family has lots of standards like RJ9, RJ11, RJ12, RJ13, RJ14, RJ45, RJ48, RJ15, RJ61, RJ71 and more. The last 2 digits specify the wiring standards.6P4C connector acronym for 6 Position 4 Conductor. So, RJ 11 falls under 6 positions 4 conductor standard whereas RJ12 falls under 6 positions 6 conductor standards.

RJ11

RJ 11 is a wiring standard mostly used in telephone systems. RJ11 is 6P4C wiring standard where only 4 conductors (wires) connected to the physical connector and 2 slots or positions on the socket is free. That means 2 phones can be connected via this connector. RJ11, RJ14 and RJ25 all use the 6P6C physical connector but the numbers of conductors or wires differ. RJ11 generally connects with 2 wires, RJ14 connects with 4 wires and RJ25 connects with 6 wires respectively allowing 1, 2 or 3 phone lines respectively.

RJ11 cables generally sold as 6P4C with 4 wires (2 pairs) running from central junction box but only one line is being used via single pair and other pair is kept free for future use if necessary.

RJ12

RJ12 is a 6P6C wiring standards means, 6 positions of the socket will be occupied by 6 conductors or wires. Normal home telephones used RJ11 and corporate PBX using key phones or Digital Phone Systems uses generally RJ12. In some phones we can configure 3 phone lines (3 CO lines) for an operator to answer 3 different phone lines. Those types of phones are generally connected via RJ12 or RJ25.

Depends on our needs we can select RJ11, RJ12, RJ14 and RJ25. But in general home connections are RJ11.