568A or B?

Mar 27, 2010 26 Replies

I'm running an Ethernet cable in the walls from the wireless router to the church office. (everything else is wireless, but one computer needs a wired connection.) I'll be terminating the cable with 8P8C modular keystone jacks. Am I supposed to use 568A or 568B color codes?



The more I read about it, the confuseder I get; I know for a straight-through cable the colors don't really matter electrically (as long as I pair them correctly) but I don't want to make a mess for the next guy that wants to add on, or has to replace the cable.



It kind of looks like male-to-male cables are traditionally wired A and female-to-female are wired B. ???



Thanks, Bob


zxcvbob wrote in news: snipped-for-privacy@mid.individual.net:

You want answers from home repair for computer things? OK, throw some dry wall over the wires add some cement. That'll do it.

I figured it was better than asking on the cooking group (or rec.gardening, or rec.guns)

Bob

They have femaie ethernet cables? !!

Ethernet with work in any combination 568A or B but just in case you end up using those cables for something else in the future, stick with one particular pinout for all cable ends for the whole facility. Which exact one will depend on what you MAY use those cables in the future. 568A may be more convenient if you may use those cables for phones, 568B - for data applications.

Patch cords can be wired either A or B as long as they have the same pinout on both ends.

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It's one of the things I do for money. All of the network cabling I install and all of that installed by the other guys I know is 568B. Patch cables will often follow the 568A pattern but it doesn't matter because they're the same on both ends unless you run across a critter known as a "crossover cable". The difference between 568A and 568B wiring is that the green and orange pair positions are reversed.

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You can use either but they must be the same on both ends. Also depends on local telecommunication codes. Both are 8 wire UTP so it doesn't really matter if 586A starts out with W/green and 586B starts with W/orange as long as it's punched down the same way on each end. And same with cables. Just make sure both ends are either 586A or

586B. Digital signals could care less about what color they ride inside of.

Most common in institutional and business use in North America is B

Wire EVERYTHING as B. Switching between the two just complicates things - particularly if you go to Giga ethernet. (which uses all 4 pairs)

It doesn't matter which code you use, as long as you use the same one on both ends of any given run. I personally use the "b" for everything. It is the way the store bought patch cables are.

You can do it either way, just be consistent. You can even make up your own standard if you're so incline.

Swtich to B for a crossover, but I don't think that applies, given what you've described.

It is true but the (anecdotal) reason for that is so archaic it's not even funny: it was instilled by AT&T back in the early 80s so people would not take digital phones from work (B) and plug them into home phone outlets (A or, more likely, RJ). A ring signal from an analog phone line would kill a digital phone. None of that matters anymore, so the OP would be fine with either A or B.

Well, again, if he ever to re-purpose the cables for phones (you never know, cables survive for so long that there may be a need 10 year later),

568A would make it a bit easier to use one cable for two or more parallel lines.

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For the first ethernet cables I made, I didn't pay attention to pairing. They worked OK for 10mbps, but when I when to 100mbps the connect lights came on but there was no data connection.

Be sure to wire both ends of the cable the same.

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I have a couple of double-female adapters.

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If you are just making a jack to jack, it doesn't matter. If the church has a hub with a punch down block, the punch down block will be labeled.

The church has a 66 punchdown block for the phones (I put that in last week) but not for the Ethernet.

The jacks have 110 punchdown terminals, and they are labeled for both A & B but the labels don't make any sense. I'm gonna have to use a continuity tester and figure out the pin-out (I think it's

1234 down one side and 8765 on the other, where the outermost terminals are 4 and 5) I may do that tonight.

I've about decided to use B. If the jack is wired the way I think it is, the orange pair (for B) goes on the inner left and the brown pair on the right, then the green pair gets separated left and right in the next terminals, then blue in the outermost terminals. To wire it "A", just swap the orange and green.

If I was evil, I would put a crossover cable in the walls. ;-)

Bob

Oh, I get it. the thing snipped from two posts ago. Thanks.

You are correct - and as I said before, go with the "B". Doesn't matter if it's the plug end or the Keystone jack -

BTW strip the insulation at least an inch. The trick is getting the wires as flat as you can before snipping them to the correct length.

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