T568A and T568B Twisted-pair Ethernet Standards

by | Feb 17, 2011 | Network Administrator

I get questions about the standards for network cabling all the time, usually from people wanting to try and do it themselves.

While I have them memorized, others may not. So, this little guide should help those who haven’t worked with the standards enough to have them memorized.

The T568A and T568B Twisted-pair Ethernet Standards utilize a 8P8C (8 position 8 contact or 8 position 8 conductor) modular connector known as an RJ45 Plug. The RJ45 Plug is for use with a RJ45 Registered Jack. The following images should help when reading the tables below.

rj45-8p8c-plug-close-up

rj45 8p8c plug

TIA/EIA-568 T568A termination
Pin Pair Wire Color
1 3 tip wire white green stripe pair 3 wire 1 white/green
2 3 ring wire green pair 3 wire 2 green
3 2 tip wire white orange stripe pair 2 wire 1 white/orange
4 1 ring wire blue pair 1 wire 2 blue
5 1 tip wire white blue stripe pair 1 wire 1 white/blue
6 2 ring wire orange pair 2 wire 2 orange
7 4 tip wire white brown stripe pair 4 wire 1 white/brown
8 4 ring wire brown pair 4 wire 2 brown

The information from the table above, can be used to produce an ethernet cable, where both ends match the following configuration:
rj45 8p8c T568A plug

TIA/EIA-568 T568B termination
Pin Pair Wire Color
1 2 tip wire white orange stripe pair 2 wire 1 white/orange
2 2 ring wire orange pair 2 wire 2 orange
3 3 tip wire white green stripe pair 3 wire 1 white/green
4 1 ring wire blue pair 1 wire 2 blue
5 1 tip wire white blue stripe pair 1 wire 1 white/blue
6 3 ring wire green pair 3 wire 2 green
7 4 tip wire white brown stripe pair 4 wire 1 white/brown
8 4 ring wire brown pair 4 wire 2 brown

The information from the table above, can be used to produce an ethernet cable, where both ends match the following configuration:
rj45 8p8c T568B plug

A Crossover cable is a different story.

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About the Author:

WebDevRobert

Innovative Technology Professional, working on IT/OT Convergence & Security, in the foundry industry.

Website Designer/Developer since the mid 1990’s.

Apple, Linux and Network Administrator since the late 1990’s.

Background includes several years of IT/OT and IIoT Administration, Communications Infrastructure Design and Project Management.

Currently the VP of Technology for Oil City Iron Works, Inc., in Corsicana, TX.

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