CAT 5 ... T568A or T568B

I had flood wired the house with CAT 5e, and now need to terminate all faceplates.

I can use T568A or T568B .......... Googling & searching UK.d-i-y seems to bring up different answers. When we are talking about the faceplates ... for UK would it be best to wire them, to T568B standard? i.e. T586B 1 wh/orange 2 orange 3 wh/green 4 blue 5 /wh/blue 6 green 7 wh/brown 8 brown

However on several times on this group it recommends the article at :

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states .... " All new installations should be carried out using the 568A standard and cables only to be terminated to 568B specification on existing 568B systems."

and

" ISO says, "There is no reason to change existing 568B installations to 568A although all new installations should be implemented with

568A."

This seems to contradict the many posters of this group who say to wire out in T568B

So which should I use ???

Secondly if I use for example T568B at outlets, do I use same colour scheme at patch panel ends ... there were comments made that if you wire to T568B then you only need straight through patch cables not crossover ... but again this is often negated in other comments.

Reply to
Osprey
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I think that the best indicator is product availability. There seem to be a lot more items around for 568B than 568A.

Certainly one should stick to everything of one part of the standard and not mix them.

Also recommended if you don't have one is a CAT5 continuity tester. Unless you are going to go for Fluke TDMs or something like that, these are very cost effective. There is a sequencer unit for one end with a battery and a box with 4 LEDs on the other. Plug them in using patch cables and the LEDs should light in sequence and the same colour. This will detect that all pairs are connected, to the right places and the correct way round. For about £20, it's a great time saver.

Reply to
Andy Hall
[snip]

Personally I have always used 568B, and have never seen 568A in the commercial installs I've needed to look at. It really doesn't matter though - they both do exactly the same thing.

A crossover cable is a patch lead terminated in 568A at one end and

568B at the other. You MUST use the same at both ends of your structured wiring otherwise the structured wiring itself becomes a crossover cable. A lot of the consumer grade networking kit (like Netgear) does auto crossover so you might not notice a problem straight away. But if you try running some other system like a Digital PBX or Video over the Cat5 you will end up confused by the results! If you look at an office patch panel the only crossovers you will find are between the network switches. All the PC to wall plate leads, and the leads from the network switch to the patch panel, will be straight cables.

To get a reliable connection you should untwist the least amount of wire at each end and get a proper spring loaded krone tool to do the job, and if you have a lot of sockets to terminate then it's worth getting one of the cheep (=A320 ish) Cat5 testers too. I've wasted a lot of time in the past cutting off ends and reterminating them when a tester would have shown up the dodgy pair in seconds.

-- Gareth Davis snipped-for-privacy@garethdavis.net

Reply to
newsgroups

Not mixing the two is a good idea, confusion will come by the bucket full if you do.

AFAICT the only difference is which colour pair is connected to which pins. The designation of pins and functions is the same for both. Electrons don't care a fig about insulator colour...

There *might* be an issue with the relationship of pair positions within the cable but I've never seen any reference to that or indeed if there is a laid down position for each pair in a cable.

Reply to
Dave Liquorice

or colour...

Yes there is a relationship. Its covered by the cat5 / cat6 standards which specify things that cable twists, etc. effect.

I used 568b everywhere except crossovers which have 568a at one end. Now I use 568b everywhere and fit a cross over adapter when I need one.

Reply to
dennis

I did some network wiring recently and the connectors (from TLC) came marked with both colour codes. I used 568A because that's what's recommended here:

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Reply to
Andy Wade

It doesn't matter, so long as you do the same at each end. Both use the correct twisted pair arrangment :

Pins 1+2 are a pair, and pins 3+6 are a pair.

Personally, I use the 'B' standard, and just about every installation and patch cable I've looked at has used 'B' also.

Be aware that if you wire one end 'A' and the other end 'B' you have just made a crossover cable!

Reply to
Ron Lowe

For about =A320, it's a great time saver.

Any link for this ? .... sounds like I ought to buy one.

Reply to
Osprey

Typing CAT 5 tester into Google brings up a load - e.g.

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typical of what I had in mind.

Another essential investment is a proper Krone (or equivalent) punch down tool.

Plastic ones and screwdrivers are definitely verboten.

Reply to
Andy Hall

Have you a reference? The only thing I can find is all about the termination not the actual core/pair layout within the cable.

I have found references that say 568A and B are technically identical so presumably the relative pair positions within the cable are not actually important.

Reply to
Dave Liquorice

Its probably on here somewhere

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568a/b standard defines the cable charachteristics but many people only see the pinout parts of the spec. wikipedia has`some info.

The four pairs are wound at different rates to reduce cross talk so there are differences in the pairs. The nominal impedance is the same though.

Reply to
dennis

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