Data & Telephone wiring standards

Wiring Standards

Telephone and Data Wire Color Codes

Telephone Cabling with Station Wire

Phone cable generally contains two pairs of wires, for two phone lines. In station wire, the first pair is green (tip) and red (ring); the second is black (tip) and yellow (ring). The way you remember this is that there are two holidays: Christmas and Halloween.

RJ-11 Plug Wiring

This is the wiring for the plug side of an RJ-11 connector. Can you say "BuRGundY"? (Think about cheap red wine; I know I do.) The diagram is shown with the "hook" - the little thing you press on to get the plug out - underneath. RJ-11 sockets always have the colors indicated on the terminals.

Note that the connector on the other end of an RJ-11 connector is wired in reverse order. That is, if you stretch the cable out flat, the black wire stays on the left all the way to the other end, including through the connector with the hook oriented down also. Also note that the RJ-11 connector has six terminals on it. Only the middle 4 are normally used. Line 1 is the center pair: red and green, as in Christmas.

Some premade phone cables only have the center two wires. These cables will be absolutely useless for two line devices.

Telephone Cabling using Cat5 or UTP

Nowadays, Cat5 cable is commonly used instead of station wire for telephony. In which case, start with the blue pairs and use the orange pairs for the second line.

Pair 1	White with Blue	Tip
	Blue	Ring
Pair 2	White with Orange	Tip
	Orange	Ring
Pair 3	White with Green	Tip
	Green	Ring
Pair 4	White with Brown	Tip
	Brown	Ring

Nowadays, Cat5 cable is commonly used instead of station wire for telephony. In which case, start with the blue pairs and use the orange pairs for the second line.

You may find that wires with both color schemes have been used in your installation. Use the table below to translate between the two schemes.

White with Blue	Green	Tip
Blue with White	Red	Ring
White with Orange	Black	Tip
Orange with White	Yellow	Ring

Telephone Cabling with 25-pair to a 66 or 110 Block

The primary color order is blue, orange, green, brown, and slate.
The secondary color order is white, red, black, yellow, and violet.

Tip is the secondary color, with marks of the primary color (i.e., white with blue marks).
Ring is the primary color, with marks of the secondary color (i.e., blue with white marks).

Group 1		Pairs 1-5
Group 2		Pairs 5-10
Group 3		Pairs 11-15
Group 4		Pairs 16-20
Group 5		Pairs 21-25

T-568B Color Code for RJ-45 Plug

Eight-conductor data cable contains 4 pairs of wires. Each pair consists of a solid colored wire and a white wire with a stripe of the same color. The pairs are twisted together. To maintain reliability on Ethernet, you should not untwist them any more than necessary (like about 1 cm).

I strip about 1" of jacket off, then separate the wires in order, pinching firmly between thumb and finger, while bending back and forth and mashing. Then I snip off to a length of 5/8", +/- 1/16" using very sharp scissors. Ensure that the jacket is in the RJ45 plug far enough that the keeper will crimp down on it.

RJ46
There are two wiring standards for these cables, called "T-568A" and T-568B" They differ only in connection sequence, not in use of the various colors. The illustration shown is for T-568B. The pairs designated for 10BaseT Ethernet are Orange and Green. The other two pairs, Brown and Blue, can be used for a second Ethernet line or for phone connections.

Note that the Blue pair is on the center pins and conveniently corresponds to the Red and Green pair in a normal phone line. The connections shown are specifically for an RJ45 plug (the thing on the end of the wire). The wall jack may be wired in a different sequence because the wires are actually crossed inside the jack. The jack should either come with a wiring diagram or at least designate pin numbers that you can match up to the color code below.

Pin Number Designations
There are pin number designations for each color in T568B as well. The pin designations are as follows:

Pin	Color	Pair	Name

1	White with Orange	2	TX+
2	Orange	2	TX-
3	White with Green	3	RX+
4	Blue	1
5	White with Blue	1
6	Green	3	RX-
7	White with Brown	4
8	Brown	4

Note that the odd pin numbers are always the white with stripe color.

Wiring Diagrams for Straight, Crossover & Double LAN Cables

Note: The hook is underneath in all cases and Pin one is always on the Left

Straight Cable	Color Code	Color
Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8	white orange orange white green blue white blue green white brown brown

Crossover Cable	Color Code	Color
Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8	white green green white orange blue white blue orange white brown brown
The other side is a straight through cable see Straight through diagram

Double LAN Cable	Color Code	Color
LAN1 Pin 1 Pin 2 Pin 3 Pin 6 LAN 2 Pin 1 Pin 2 Pin 3 Pin 6	white orange orange white green green blue white blue white brown brown
The other side is a straight through cable see Straight through diagram

Construction Notes from Poge Smit

Ensure that enough outside jacket is trimmed back to wiggle the pairs around for a nice and straight parallel alignment, then trim the extra with enough left to slide the connector onto the pairs without getting hung up on the jacket, but not so long that the jacket can't be snuck right into the strain relief as you sneak the pairs all the way to the front of the connector for the crimp.

Make certain the connector blades all bottom out through the pairs after the crimp.

There are also two _basic_ types of RJ-45's. One is for solid pair, the other is for stranded. The correct connector for solid is a simple notch that pinches through the jacket for contact. The one for stranded is a bayonet type which just slices into the stranded type CAT5, but can bend without proper contact when used with solid strand CAT5.

Use good quality and properly adjusted crimpers.

Ya get what ya pay for.