RJ45 Wiring Tips

Many guides go over the top quoting standards, and in fact, I saw a couple that made my head spin, so I decided to make this simple little guide. It is not perfect but it has some useful information based on my extensive networking experience.


It is always good to have standards, and over the years, I managed to boil it down to just two. I have decided to do my visitors a favour and mention them only once!

  • ANSI/TIA/EIA-568-B.2
  • ISO/IEC 11801

Basic Facts

Although sometimes called an RJ45 socket, its proper name is 8-position modular jack.

The letter T in T568A refers to termination, and 568 to the order of termination.

Scotty! Shields!

Frequency (MHz)CategoryClass
1000CAT7AClass 7A
600CAT7Class F
500CAT6aClass EA
250CAT6Class E
100CAT5eClass D

The high frequency transmission in the MHz range is very useful for creating electromagnetic noise therefore shielded cables are vital.

Label Colour Coding

Colour CodePurpose
RedTelephone Systems
YellowAuxiliary Circuits
GreenNetwork Connections
BlueHorizontal Cabling
PurpleCommon Equipment
WhiteBackbone First Level
GrayBackbone Second Level
BrownBackbone Inter-building

It is always a good practice to label your wiring with a colour code scheme so that you can tell at a glance what you are looking at. It can save much time having to trace each wire when diagnosing faults.

New Network

If you are planning to upgrade your network system, then here are some useful tips.

  1. Always choose the best speed and technology that is available today. It might seem overkill or unnecessary but after five years you will be glad, thinking it was a good call.
  2. There are many proprietary solutions on the market, but stick to the proper structured cabling systems. The beaten path is always tried and tested, and works out cheaper in the end.
  3. A single structured cabling system that carries data, voice and telephone is the best.
  4. Quality wiring and fixtures are the best because they last longer and provide a useful service. The cheap stuff usually breaks down after a few years.

This Article Continues...

Network Cables
RJ45 Wiring Diagram T568A Standard
RJ45 Wiring Diagram T568B Standard
RJ45 Wiring Straight-through Cable
Crossover Cable Wiring Pinout and Diagram
RJ45 Wiring Tips
How to use RJ45 CAT 6 Crimp Tool
NS-468 LAN Cable Tester