Cat5 wiring

The_KiD · 12 Jul 2007 at 11:05

Can anyone tell me what difference it makes whether using the correct standard for wiring this cable or instead just making sure both sides are the same.

Correct Standard:

In my min it shouldnt make any difference, but then why have a standard?

Phil99 · 12 Jul 2007 at 11:12

The striped ones are twisted with the solid coloured ones (i.e. blue solid & blue striped are twisted together), hence the name 'twisted pair', but I'm not sure if that makes a difference depending on which wires you use. There's a standard because if you want to replace one end of a CAT5 cable you want to know exactly which wires go where, instead of having to find the other end, work out which wires are going where etc etc.

Trifid · 12 Jul 2007 at 11:24

That is the correct way for a straight through. (I remember it by flood plains (muddy), grass and then river. With orange on the left.

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The_KiD · 12 Jul 2007 at 11:35

So not using the "standard" and wiring both ends in the same order is just the same as using the standard?

Trifid · 12 Jul 2007 at 11:38

Well it would work identically. I wouldn't be impressed if I came in and saw it not done to the standard though.

I would go as far as to find out who did the wiring and hunt them down (to teach them the standard.

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Dist · 12 Jul 2007 at 13:49

it doesnt matter what colour you put where, what matters is where the pairs are positioned.

The point of twisted pairs is that you can send a signal along one wire, send the opposite signal along the twisted wire, and when it gets to the end, the signal from the one wire is subtracted from the other wire. Since any interference would be the same on both wire, 1 - 1 = 0, so the interference gets canceld out, while the real signal can get through.

If you dont wire the pairs up in the correct position, the interference may not be canceld out correctly. But as long as the wires are in the same locations on the rj45 connecters on both sides of the cable, then it should still work.

If you wiring cables yourself, there is no excuse not to wire them the correct way, it takes a few seconds to look up on the internet the correct way to wire them, so why not simply wire them that way instead of asking if its ok to wire them the wrong way?

The_KiD · 12 Jul 2007 at 13:56

lol I was simply wanting to know if there is a difference as I was having a discussion with an engineer from a security company who swore blind that because we had a cable that wasnt wired to standard he would not support the problem we were having (never mind that I then replaced it with a correctly wired cable and it still didnt work).

So yeah 99% of the time my cables are done to standard however I simply wanted to know if it made an actual difference.

BenST · 12 Jul 2007 at 13:59

Simple answer is no, it doesn't make any difference whatsoever. Dist's post is an excellent reference to use.

Snapshot · 12 Jul 2007 at 15:01

I once wired up a CAT5 switch unit incorrectly as it wasn't clearly marked. Everything was consistent and it passed the continuity tests but it didn't work with real data and I had to go back the next day to fix it.

milkinc13 · 12 Jul 2007 at 18:45

Trifid said:
That is the correct way for a straight through. (I remember it by flood plains (muddy), grass and then river. With orange on the left. )

I like that way of remembering the way the cables go.