RJ11, RJ14, RJ25
RJ11 is a physical interface often used for terminating telephone wires. It is probably the most familiar of the registered jacks, being used for single line POTS telephone jacks in most homes and offices in North America and many other countries.
RJ14 is similar, but for a two line telephone jack, and RJ25 is for a three line jack. RJ61 is a similar registered jack for four lines. The telephone line cord and its plug are more often a true RJ11 with only two conductors.
Contact arrangement
All of these registered jacks are described as containing a number of potential contact "positions" and the actual number of contacts installed within these positions. RJ11, RJ14, and RJ25 all use six-position modular connectors.
RJ11 wiring
An RJ11 is nearly always a 6P4C jack, with four wires (two of them unused) running to a central junction box and uses two of its six possible contact positions to connect tip and ring. It could therefore be wired with a 6P2C (six position, two conductor) variety of modular jack, but this is rarely done.
The extra wires are used for various things such as a ground for selective ringers, low voltage for a dial light, or as an 'anti-tinkle' circuit to prevent a pulse dialing phone from ringing the bell on other extensions. With tone dialing these are not required so the connectors are used to provide flexibility so the jack can be rewired later as RJ14 or to supply additional power for special uses.
Powered version of RJ11
Pinouts
| pin | RJ25 | RJ14 | RJ11 | Pair | T/R | ± | Color | Old |
|---|---|---|---|---|---|---|---|---|
| 1 | X | 3 | T | + |  white/green
|
 orange
| ||
| 2 | X | X | 2 | T | + |  white/orange
|
 black
| |
| 3 | X | X | X | 1 | R | - |  blue/white
|
 red
|
| 4 | X | X | X | 1 | T | + |  white/blue
|
 green
|
| 5 | X | X | 2 | R | - |  orange/white
|
 yellow
| |
| 6 | X | 3 | R | - |  green/white
|
 blue
|
While the old solid color code was well established for pairs 1 and 2, there are several conflicting conventions for pair 3. The colors shown above were taken from a vendor of "silver satin" flat 8-conductor phone cable that claims to be standard. At least one other vendor of flat 8-conductor cable uses the sequence blue, orange, black, red, green, yellow, brown and white/slate.
Holding the connector in your hand tab side down with the cable opening toward you, the pins are numbered 1-6, left to right.
See also
- BS 6312 - British equivalent to RJ25
- 4P4C - Handset jack
- 8P8C - Eight position connector used with Ethernet
- Modified Modular Jack -- A variation used by Digital Equipment Corporation for serial computer connections
- Telephone plug - Includes a table of the countries where RJ-11 and other telephone connectors are used
