UTP – Wiring schema

In the past I didn’t really care for the proper color ordering of wires in 8P8C connectors (aka “RJ45”) while making UTP cables for my personal use. I knew that termination is standardized (T568A and T568B) but never took the time to memorize correct color termination – since I always needed “ordinary” UTP cables with straight through wired pins.
Of course, when you want to make a cross-over cable you need to know which pins need to be swapped. I found Wikipedia explanation so good and comprehensive that I decided to post a copy of schema termination picture here, for my future quick reference:


From now on I’ll stick with T568B wiring schema when I’ll need to wire “ordinary” UTP cables. For the cross-over cable we need to use T568A at one end of the cable and T568B at the other. * [Note added: 5th December 2008]I soon realized I made a mistake, what I wrote is true for 10Base-T and 100Base-TX and not for 1000Base-TX cross-over cable.

10Base-T and 100Base-TX cross-over cable follows above schema, at one end of the cable is T568A and at the other end T568B.

Gigabit cross-over cables are different, as I realized only after I read Wikipedia piece. Gigabit cross-over cable follows this schema:



Posted on 04.12.2008, in Other and tagged . Bookmark the permalink. Comments Off on UTP – Wiring schema.

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