Cat5e Wiring Diagram - Wirral & District ARC

(T-568B Colour Code for RJ-45 Plug)

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

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 colours. 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 colour code below.

 Pin Number Designations

There are pin number designations for each colour in T568B as well. The pin designations are as follows:

Colour Codes for T568B

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

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

Wiring Diagram for Straight Through & Crossover Cables
 

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