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Cat5 568B cable wrong... but right. Huh?

Explain this and I'll send you some Christmas cookies...

I have a OEM cat5 cable. On the side it says "EIA-568B".

You and I know that, at the very least, pins 1,2 and 3,6 should match up. You and I also know what 568B says the wiring order needs to be:

white orange/orange white green/blue white blue/green white brown/brown

But this OEM cable is wired...

white orange/orange white green/white blue green/blue white brown/brown

Here's the kicker: the OEM cable works. From the cable modem to the router it works. From my laptop NIC to the router it also works. But the pins don't match: 1,2 ... 3,5 ... 4,6, ... 7,8

In short, I must have some bad info somewhere. I should be happy it works but I want to understand why this "wrong" cable is working. Cheers, Brian

Reply to
rh128592
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OK. So one pair is split, if you can tell the wh-gr from wh-bl.

Not at all surprising from the modem to the router, since this is short and 10baseT. NIC to router is a bit more surprising because this usually runs at 100baseTX, but it may still work for a short cable.

-- Robert

Reply to
Robert Redelmeier

If I follow you; then this is wrong.

1 w/or 2 or/w 3 w/gn 4 bl/w 5 w/bl 6 gn/w 7 w/bn 8 bn/w

is from the chart...

No mystery. On a short cable, in good circumstances; almost anything works. It's when you have 100 meters, colo with adjacent cables. slightly kinked, etc. that the spec is vital.

Because the Ethernet receiver is able to hear the far end bits even in the face of local interference. In short, you lucked out.

Reply to
David Lesher

It might work for short distance, but not long. It doesn't matter what the colours are, provided proper pairing is maintained. However, good practice dictates using EIA/TIA 568A or B. Chuck that cable and get a good one. Cables are cheap.

Reply to
James Knott

EIA/TIA 568B is a standard not a pin out. T568A and T568B are pin out. That cable is just saying in meets the EIA/TIA standards. The T is important people!

Reply to
t568aort568b

Thanks all. Good to know. I just learned how little I know. And supposedly I'm the family computer "expert".

Cheers, Brian

Reply to
rh128592

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