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 Question by Mar Piola posted 24 Oct 2005

I just confused with the color coding. Im using cat5 but is it really true that T568A is faster than T568B. I have read in the internet that these two color codings will both work equally, T568B is commonly used but one tech in a chat room said, "T568A is faster than T568B with its range in ft..

thank you very much..

 Answer by Joseph Golan posted 25 Oct 2005
Dear Mar,

Someone is either pulling your leg or this chat room has no idea what they are talking about. It won't be the first time that I have seen this.

First the difference between T569A & T568B.
T568A has the Orange/White pair on pins 3 & 5 and the Green/White pair on pins 1 & 2
T568B has the Orange/White pair on pins 1 & 2 and the Green/White pair on pins 3 & 6.

It just so happens that 10BaseT and 100BaseT Ethernet both use the pairs on pins 1-2 & 3-6 for transmission and receiving. As they both use the same pairs, just in reverse order, there cannot be any difference in performance. If you have 1000BaseT, it uses all 4 pairs for transmission and receiving (bi-directional) and again there is no difference in performance between the two wiring schemes.

The standard for both wiring schemes is the same at 90 meters (295') for the link, distance does not come into play.

Joseph Golan, RCDD

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