The RJ45 cable is a standard cable which has four twisted pairs of colors. It is easy to crimp a RJ45 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 colors have to be reversed. Learning how to crimp a RJ45 cable and making straight and cross cables prove to be useful as different types of wires of varied lengths are required to build a network.

What you need?

A reasonable length FTP cable

Two RJ45 tips

A clip crimp

How to proceed?

Strip the cable to 2 cm at each end and separate the strands.

They are usually divided into 4 twisted pairs of colors:

Orange / orange-white

Green / green-white

Blue / white and blue

Brown / brown-white

Making a straight cable

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 code used is:

1) orange-white

2) orange

3) green-white

4) Blue

5) blue-white

6) Green

7) brown-white

8) brown

Making a crossover cable

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

The standard EIA / TIA 568 (A & B)

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

For crossover cable 10/100baseT

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

To complete crossover cable or cross gigabit

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.

A picture to better understand the coding

Photo: 123RF