Click for Data cabling Termination, color codes & specs

 

 

 

 

 

 

 

 

 

 

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Category 5 & 5e data wiring color codes

Color codes for RJ-45 Ethernet Plug:

Each eight-conductor data cable (Cat 5) contains 4 pairs of wires. Each pair consists of a solid color wire and a white wire with the same color binder. Each of the pairs are twisted together. To maintain reliability on Ethernet, you should not untwist them any more than 1 centimeter.
The pairs designated for 10/100 BaseT Ethernet are orange and green. The other two pairs, brown and blue, are unused unless running Gigabit Ethernet. The connections shown are specifically for an RJ45 plug, used on a patch cord. Solid core wire should not be used for patch cords as it will break more easily when bent or kinked.

There are two wiring standards for these cables, called T-568A and T-568B. They differ in pin assignments. The illustration above shows both standards. With the T-568A specification the green and orange pairs are located on pins 1, 2 and 3, 6 respectively. The T-568B specification reverses the orange and green connections, so that the blue and orange pairs are on the center 4 pins, which makes it more compatible with the telco voice connections.

T-568A is supposed to be the standard for new installations, and T-568B is the alternative.

Pin Number Designations:

In LANs, as specked by 568, there are two possible pin outs, called T568A and T568B, that differ only in which color coded pairs are connected - pair 2 and 3 are reversed.

T-568A

Jack Pin Color Pair Description

1 white/green 3 RecvData +
2 green 3 RecvData -
3 white/orange 2 TxData +
4 blue 1 Unused
5 white/blue 1 Unused
6 orange 2 TxData -
7 white/brown 4 Unused
8 brown 4 Unused

 

 

 

T-568B

Jack Pin Color Pair Description

1 white/orange 2 TxData +
2 orange 2 TxData -
3 white/green 3 RecvData +
4 blue 1 Unused
5 white/blue 1 Unused
6 green 3 RecvData -
7 white/brown 4 Unused
8 brown 4 Unused

 

 

 

Note: The odd pin numbers are always the striped wires.

Straight-Through vs Cross-Over cables:

In general, the patch cords that you use with your Ethernet connections are "straight-through", which means that pin 1 of the plug on one end is connected to pin 1 of the plug on the other end (for either standard). The only time you cross connections in 10BaseT is when you connect two Ethernet devices directly together without a hub or connect two hubs together. Then you need a "cross-over" patch cable, which crosses the transmit and receive pairs. An easy way remember how to make a cross-over cable is to wire one end with the T-568A standard and the other with the T-568B standard.

Category 5e or Ethernet Termination:

Unshielded twisted pair cables are terminated with standard connectors, jacks and punch downs. The plug is often referred to as a "RJ-45", the male connector on the end of a patch cord is called a "plug" and the receptacle on the wall outlet is a "jack."

The cable pairs are color coded as follows:

Pair 1 is white-blue/blue,
Pair 2 white-orange/orange,
Pair 3 is white-green/green
Pair 4 is white-brown/brown.

 

 

Jacks usually have punch downs on the back or can be terminated without punch downs using special manufacturer's tools or even a cover for the connector. Again, you MUST keep the twists as close to the receptacle as possible to minimize cross talk.

Note that Cat 3 jacks and all plugs are going to use these color codes. However, Cat 5 jacks have internal connections that continue the twists as close to the pins in the jacks as possible. Thus the pin out on the back of the jacks will not usually follow these layouts! Always follow the color codes on the back of the jacks to insure proper connections!

Crossover Cables:

Normal cables that connect a PC/NIC card to a hub are wired straight through. That is pin 1 is connected to pin 1, pin 2 to pin 2, etc. However, if you are simply connecting two PCs together without a hub, you need to use a crossover cable made by reversing pair 2 and 3 in the cable, the two pairs used for transmission by Ethernet. The easy way to make a crossover cable is to make one end to T568A color coding and the other end to T568B. Then the pairs will be reversed.

Punch downs:

Punch downs come in 4 varieties: 110, Bix, 66 and Krone. The most popular termination style for Data cabling is the 110 punch down. For telephone cabling is the Bix block. The 66 Block is the old style bix termination, & the Krone style is rarely used in North America.

 

	110 block
	BIX Block with BIX 1A's
	66 block

 

 

Color Codes For Punch downs:

Punch downs of all types are always made with the pairs in order with the white/stripe wire first, then the colored wire, Pair 1(w/blue-blue), Pair 2 (w/orange-orange), Pair 3 (w/green-green), Pair 4 (w/brown-brown). (This color code is remembered by BLOG - BLueOrangeGreen and brown)

 

 

These are punch down tools:

Datacom Solutions has installed thousands of cable runs in Vancouver and the lower mainland. We would be happy to give you recomendations on your installation.