Monday, February 27, 2012

How to correctly assemble a CAT-5 cable to RJ45 connectors

How to correctly assemble a CAT-5 cable to RJ45 connectors for regular network cables as well as crossover cables.

The
CAT-5  is a standard cable which has four twisted pairs of colours. It is easy to crimp a RJ45 coonector to CAT-5 cable and make it into a straight cable or cross the cable as required. To make a straight cable, the ends must be crimped in the same way at each end. When making a crossover cable, some wires of certain colours have to be reversed.


CAT-5 cable is usually divided into 4 twisted pairs of colours:

Orange / orange-white
Green / green-white
Blue / white and blue
Brown / brown-white


Straight Cable Colour Code


To make a straight cable, the tips must be crimped typically the same way at each end by respecting the twisted pair size.

In general, the colour code used is:

1) orange-white
2) orange
3) green-white
4) Blue
5) blue-white
6) Green
7) brown-white
8) brown

Crossover Cable Colour Code


For a crossover cable, swap 1 with 3, and 2 with 6, in the list above. This gives:

1) green-white
2) green
3) orange and white
4) Blue
5) blue-white
6) orange
7) brown-white
8) brown

Standard EIA / TIA 568 (A & B) Colour Code


Straight cable

1) white-green / white-green
2) green / green
3) white-orange / white-orange
4) Blue / blue
5) white-blue / white-blue
6) Orange / orange
7) white-brown / white-brown
8) brown / brown

Crossover cable 10/100baseT Colour Code


1) white-green / white-orange
2) Green / orange
3) white-orange / white-green
4) Blue / blue
5) white-blue / white-blue
6) Orange / green
7) white-brown / white-brown
8) brown / brown

Complete crossover cable or cross gigabit Colour Code

On Gbic 1000BaseT eg

1) white-green / white-orange
2) Green / orange
3) white-orange / white-green
4) Blue / white-brown
5) white-blue / brown
6) Orange / green
7) white-brown / blue
8) Brown / white-blue

Note:

Many Gigabits (10/100/1000 multi speed) are auto MDI / MDIX and automatically adapt to the type of cable connected.