So... here's the sp. I've bought a house and all the rooms have Cat 5
cable already in place. The wall sockets are labelled 568B on the
inside and, in order, the wire pairs are BLUE/ORANGE/GREEN/BROWN. All
the cable runs go back to the attic but the previous owner has removed
the patch panel and so all the cables are now unterminated. I believe
that ethernet uses the 2nd and 3rd wire pairs so, for 568B, pins 1,2,3
and 6 should be w/o,o,w/g and g. Pins 4,5,7 and 8 should be
bl,w/bl,w/br and br.

I'm cheap and I don't want to pay for a new patch panel.

What I want to do is simply attach RJ45 plugs to the unterminated ends
and plug them into a cheap switch but... if I wire the plug to either
the 568B or 568A pattern it fails. I know that the switch is sound as
I've tested it working using cables I made up - which also suggests I'm
using the crimps correctly - so what am I doing wrong?

On 22 Oct 2005 16:27:29 -0700, "dale"
wrote:

So... here's the sp. I've bought a house and all the rooms have Cat 5
cable already in place. The wall sockets are labelled 568B on the
inside and, in order, the wire pairs are BLUE/ORANGE/GREEN/BROWN. All
the cable runs go back to the attic but the previous owner has removed
the patch panel and so all the cables are now unterminated. I believe
that ethernet uses the 2nd and 3rd wire pairs so, for 568B, pins 1,2,3
and 6 should be w/o,o,w/g and g. Pins 4,5,7 and 8 should be
bl,w/bl,w/br and br.

I'm cheap and I don't want to pay for a new patch panel.

What I want to do is simply attach RJ45 plugs to the unterminated ends
and plug them into a cheap switch but... if I wire the plug to either
the 568B or 568A pattern it fails. I know that the switch is sound as
I've tested it working using cables I made up - which also suggests I'm
using the crimps correctly - so what am I doing wrong?


Being cheap, mainly.

For my own installation I've used only Krone or Molex stuff (using
transitions and patch panels and know what I've got.

However, I have seen cheap wrongly manufactured outlets and patch
panels where the connector labelling is simply wrong - being neither
T568-A nor T568-B. Where wiring was done using patch panels and
outlets from the same manufacturer, all was well - it was consistently
wrong.

This is one possiblility.

A second is that the previous owner has wired incorrectly.

Thirdly, when you crimped the connectors did you do them the right way
round? This is a common mistake.

Looking at the RJ-45 with the clip facing away from you, Brown is
always on the right, and pin 1 is on the left.
Again you can get this consistently wrong and a cable with both
connectors wrong, still works.

Fourth possibility is that the one or more of the wires at the outlet
socket is not punched down properly or that there is a break in the
cable. Any of the four wires being broken or shorted will cause the
cable not to work.


To check these latter points, you need to do a continuity and correct
connection test.

You can either do this quickly and quite cheaply by using a simple LAN
tester like Maplin N75CC £12.99, N59BY £19.99, or A35CJ £19.99 or any
one of a number of others.

These work by having one box which puts a DC voltage on each pair in
sequence and has a second box with 4 or 8 LEDs which will flash in
sequence if all is correct; or flash out of order, red rather than
green or with missing or more than one LED in the sequence according
to the problem. You attach one box at one end and the other at the
opposite end and cable problems become quick to find.

You can, of course, make one:

http://www.atomiccomputers.com/projects/cat5t/

but I suspect that by the time you had bought the bits, the component
cost would be not far short of the £12.99 to buy one.


Alternatively, if you can get a helper willing to spend a lot of time
on this, you could run a single wire from your location to where they
are at the other end and have them connect it to each wire in turn
while you use a continuity tester, one wire at a time. That would
give you continuity and position confirmation, but not shorts without
testing every combination.


Having said all of this, since a 24way patch panel can be obtained for
as little as £25, the exercise of titting around making up cables
seems a huge waste of time. You don't have to buy the £100 Krone
ones.

Either way, I think that a LAN tester would save a lot of frustration.







--

..andy

To email, substitute .nospam with .gl

dale wrote:


I'm cheap and I don't want to pay for a new patch panel.

And so was I.

I found plugs that specifically said they were suitable for use on solid
core cable (some are designed for stranded only, and will potentially
cut the conductor on solid core). I then used a short length of
heatshrink (handy place to write where the cable runs to) and a snag
boot to give some strain/radius relief to the cable/plug arrangement.
Careful arrangement of the conductors, a sharp pair of scissors and a
crimper borrowed from work (I got all the other bits from CPC) made it a
remarkably quick task.

What I want to do is simply attach RJ45 plugs to the unterminated ends
and plug them into a cheap switch but... if I wire the plug to either
the 568B or 568A pattern it fails. I know that the switch is sound as
I've tested it working using cables I made up - which also suggests I'm
using the crimps correctly - so what am I doing wrong?

Well I'd check that the cables have basic contunuity (see below) and
that the sockets are correctly wired to one standard or the other, or
some other arbitary fashion. Whatever it is you 'just' need to bring
the wiring out in the same way at the plug, which can be a bit mind
turning unless you actually stare into the socket bit rather than
looking at the back plate.

To help me make sure things were going well as I went I made a little
gadget consisting of a plug with solid core crimped in and then each
pair (orange, blue,, etc) twisted together (which I think remains valid
even if a non-standard scheme has been used at the sockets). I plugged
this into each socket as I crimped the other end up, and immediately
after crimping it put a spare socket onto the plug. I then used the IDC
terminals on the back of the socket and a multimeter to ensure each pair
was connected to itself, and not to any other pair.

I was pleasantly surprised to get absolutely no problems as I did this
except for one wire which I'd punched down badly at the far end in the
kitchen, so was actually able to address 'other end' problems too.
Everyhing has been working fine for 4 years, and I recently finally
switched from 10Mbs to 100Mbs (which I though might show up any latent
issues).

Subsequent to doing the above I've inherited an unused genuine Krone
24-way patch panel, but its quite a cumbersome beastie. One advantage
of the above is the compact arrangement of things under the stairs. The
Krone would take up a lot more space. If ever anything broke I'd
probably strip one of the 3 eight way sub-units in it to make things
more compact, or simply buy something suitable from eBay.
Lesser-/no-name items are darned cheap, albeit at the risk of not being
very good quality.

HTH
IanC

On 22 Oct 2005 16:27:29 -0700, "dale"
scrawled:

So... here's the sp. I've bought a house and all the rooms have Cat 5
cable already in place. The wall sockets are labelled 568B on the
inside and, in order, the wire pairs are BLUE/ORANGE/GREEN/BROWN.

That's wrong, the wires go;

1 - OR\WHT
2 - OR
3 - GRN\WHT
4 - BLUE
5 - BLUE\WHT
6 - GREEN
7 - BRN\WHT
8 - BRN

Wiring them in sequential 'pairs' is neither TIA568A or 'B so that's
why neither work.

All
the cable runs go back to the attic but the previous owner has removed
the patch panel and so all the cables are now unterminated. I believe
that ethernet uses the 2nd and 3rd wire pairs so, for 568B, pins 1,2,3
and 6 should be w/o,o,w/g and g. Pins 4,5,7 and 8 should be
bl,w/bl,w/br and br.

You've lost me on that bit, TIA568B ethernet cabling uses pairs 1 and
2, which is ORANGE amd GREEN.

I'm cheap and I don't want to pay for a new patch panel.

Your problem, not mine. My patch panel works superbly, along with
the voice panel, rack and switch.

What I want to do is simply attach RJ45 plugs to the unterminated ends
and plug them into a cheap switch but... if I wire the plug to either
the 568B or 568A pattern it fails. I know that the switch is sound as
I've tested it working using cables I made up - which also suggests I'm
using the crimps correctly - so what am I doing wrong?

Ask Geoff, apparently it's so simple anyone can do it without needing
to know what they're doing. Either his theory is wrong or you're
really really thick. Chances are, it's not as easy as everyone seems
to think.
--
Stuart @ SJW Electrical

Please Reply to group

Andy Hall wrote:

Being cheap, mainly.

;-) yup, buy a cheap patch panel and use pre made patch leads - life is
to short otherwise!

However, I have seen cheap wrongly manufactured outlets and patch
panels where the connector labelling is simply wrong - being neither
T568-A nor T568-B. Where wiring was done using patch panels and
outlets from the same manufacturer, all was well - it was consistently
wrong.

Even consistently wrong can be dodgy since you can end up with all the
right connections made but not using the matching halves of the twisted
pairs. So you end up with wiring that may run fine at 10mbps and fail at
100 etc.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
Ian Clowes wrote:
Well I'd check that the cables have basic contunuity (see below) and
that the sockets are correctly wired to one standard or the other, or
some other arbitary fashion. Whatever it is you 'just' need to bring
the wiring out in the same way at the plug, which can be a bit mind
turning unless you actually stare into the socket bit rather than
looking at the back plate.

You don't want some 'arbitrary fashion' just to maintain continuity. They
need, at least, to be wired in pairs. So it's just as easy to use the
recommended ones.

--
*You can't teach an old mouse new clicks *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sun, 23 Oct 2005 12:11:41 +0100, Lurch
wrote:

On 22 Oct 2005 16:27:29 -0700, "dale"
scrawled:

So... here's the sp. I've bought a house and all the rooms have Cat 5
cable already in place. The wall sockets are labelled 568B on the
inside and, in order, the wire pairs are BLUE/ORANGE/GREEN/BROWN.

That's wrong, the wires go;

1 - OR\WHT
2 - OR
3 - GRN\WHT
4 - BLUE
5 - BLUE\WHT
6 - GREEN
7 - BRN\WHT
8 - BRN

Wiring them in sequential 'pairs' is neither TIA568A or 'B so that's
why neither work.


That's in an RJ45 plug, Lurch.

http://www.incentre.net/incentre/frame/ethernet.html

has illustrations.

I think he means that's how the pairs are shown on the punch down of
the wall outlet. These can often be organised in a different way
depending how the PCB tracks run (if a PCB is used) for convenience of
connecting. However, I have seen some that were wrongly coded.

He went on to say:

"for 568B, pins 1,2,3
and 6 should be w/o,o,w/g and g. Pins 4,5,7 and 8 should be
bl,w/bl,w/br and br."

--

..andy

To email, substitute .nospam with .gl

"Dave Plowman (News)" wrote:

In article ,
You don't want some 'arbitrary fashion' just to maintain continuity. They
need, at least, to be wired in pairs. So it's just as easy to use the
recommended ones.

No, the original words did get a bit confused. I was making the
possibly rash assumption that even if someone had gone off piste
regarding using a true standard they would have at least kept each
pair's integrity.

Assuming pairs have been used in this way I was suggesting it may be as
well to leave them as they are at the soecket end. Personally I'd
re-punch them to be standard if there was enough slack to pull them and
trim them.

IanC

On or around Sun, 23 Oct 2005 12:54:51 +0100, Andy Hall
mused:

That's in an RJ45 plug, Lurch.

http://www.incentre.net/incentre/frame/ethernet.html

has illustrations.

Thankyou, but I am fully aware of what an RJ45 plug is and how it all
goes together. The pin order is the same for plugs and sockets though.
I won't insult you by posting pictures. :P

I think he means that's how the pairs are shown on the punch down of
the wall outlet. These can often be organised in a different way
depending how the PCB tracks run (if a PCB is used) for convenience of
connecting.

Completely irrelevant then as the outlets could be any make and be in
any order.

I know see what the OP was trying to get at and I obviously
misread\interpreted part of the post.

The summary is still the same though,the wiring is wrong somewhere,
it's not exactly difficult to make sure the wires are in the correct
terminals at each end.
--
| Stuart @ SJW Electrical. Please Reply to group. |

On 22 Oct 2005 16:27:29 -0700, "dale"
wrote:

if I wire the plug to either
the 568B or 568A pattern it fails. I know that the switch is sound as
I've tested it working using cables I made up - which also suggests I'm
using the crimps correctly - so what am I doing wrong?

Probably using plugs designed (as most are) only for stranded cable.
These cut (or miss) the solid cored on fixed cable and if they don't
fail immediately often do some time later. Far better to invest in a
patch panel. At a bit over a pound a socket it isn't as if they are
expensive :-).

--
Peter Parry.
http://www.wpp.ltd.uk/

dale wrote:

I'm cheap and I don't want to pay for a new patch panel.

What I want to do is simply attach RJ45 plugs to the unterminated
ends and plug them into a cheap switch but... if I wire the plug
to either the 568B or 568A pattern it fails. I know that the
switch is sound as I've tested it working using cables I made up
- which also suggests I'm using the crimps correctly - so what am
I doing wrong?

Either you've got the colours mixed up, or else the previous installer has.
You'll have to pull off a few wallplates and find their allocation, and then
simply copy it in the attic.

Re wiring solid cable straight to crimp plugs, it's poor practice but it
generally works ok. I've done it in our small home network (1 server, 4
desktops, 1 laptop, 1 WAP, 1 router, 2 switches) and we've had no problems
after 2yrs. At some time in the future I'll probably wire it up properly
through a patch panel, probably when we move to gigabit speed.