What you will learn
- How to strip a Cat5e or Cat6 cable without nicking the copper wires inside.
- The T568B colour order, and how it differs from T568A.
- Why no more than ½ in (13 mm) of each pair should be untwisted, and which side of the plug is pin 1.
- How to crimp the plug, read a basic cable tester, and spot a crossover cable from its lights.
T568B wiring order (pin 1 to 8)
- White/orange
- Orange
- White/green
- Blue
- White/blue
- Green
- White/brown
- Brown
T568A swaps the orange and green pairs: white/green, green, white/orange, blue, white/blue, orange, white/brown, brown. Both standards work equally well. Use the same one on both ends of every cable, and across the whole install.
Pin 1: hold the plug with the gold contacts facing you and the clip on the far side. Pin 1 is on the left.
What you need
- Cat5e or Cat6 cable.
- RJ45 (8P8C) plugs that match the cable: Cat5e or Cat6, and made for solid or stranded wire.
- A crimping tool for 8P8C plugs.
- A cable stripper, or the stripping blade on the crimper.
- A cable tester that shows the wire map.
Common mistakes
- Different standards on each end. T568A on one end and T568B on the other makes a crossover cable. The tester shows 1 lighting 3 and 2 lighting 6.
- Too much untwisted wire. More than ½ in (13 mm) adds crosstalk, and the jacket ends up outside the plug’s strain relief.
- Wires that stop short. Look through the nose of the plug before crimping: all eight copper ends should touch the front.
- A split pair. If you mix up wires from different pairs, a basic tester can still show every light in order, but the cable will be slow or unreliable. Follow the colour order exactly.