CAT5 wall socket - AAARRRGH!

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Yes, the wiring *is* that sensitive. To get the noise rejection of differential signalling down twisted pairs, the pairs need to be both paired, and twisted. Even half an inch of untwistedness, Hextraspeshally for the pair which goes across pins 3-6 (widest separation), can cause much worse performance. Your network will still "work", as the link-layer and upwards will detect garbles and cause retransmits; but your performance will be in the Saniflo and margin for errors decreased.
You may well get away with poor wiring practice: the standards are there so that properly-installed stuff will work over the advertised 100m length at advertised speeds, with the advertised number of plugs and sockets along the way (patch panels, etc.) But as you're d-i-y'ing, do yourself a favour and do the job right. The proper punchdown tool, rather than the plastic toy; keeping the twists in place; not pulling hard on the cable or putting excessively sharp bends in the route (a 1 inch/3cm min radius is good, 2in/5cm better); no nasty staples (they push the wires too close together), rather nice loose cable ties - that's the way to go. Do it right once, and forget about it for the next 10 years.
HTH, Stefek
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On 11 Nov 2003 23:46:53 GMT, snipped-for-privacy@hp.com wrote:

Hextrawhatally? We seem to be getting away with it OK RX packets:117723153 errors:0 dropped:0 overruns:0 frame:0 TX packets:131344062 errors:7 dropped:0 overruns:7 carrier:7
The cable lengths are much shorter than 100m, maybe 20-30m for the longer runs. Another office with a similar setup, but with longer cables (4 storey building) also works fine, although that is only running at 10Mbps. That office has an even worse setup, as it still has the 25 pin wall sockets left in place, with RJ45 adaptors plugged in with around 2 inch of floating wire in the adaptor. Dunno if the overall screening on the serial cable would make a difference.

If we ever do rewire it will be done, right, but our bodge has been forgotten about for the last 8 years.
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Yes it is. Also untwisting the pairs too much can make it harder, rather than easier to wire things up.
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you could try there. My 'proper' push down tool cost around 6 at Denmans.
--
Chris Green ( snipped-for-privacy@x-1.net)

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That old Screwfix magic bites again.
I think I'll just have.....because it saves on the postage :-)
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Maplin used to do a similar tool (I don't have an up to date catalogue) but that was about 15 three years ago - so the Screwfix one is cheaper even if you have to pay postage!
Roger
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On Tue, 11 Nov 2003 17:11:32 -0000, "Roger Mills"

It's even better when you can 'borrow' one off a cabling monkey :) -- cheers,
witchy/binarydinosaurs
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On Tue, 11 Nov 2003 14:38:59 -0000, "David W.E. Roberts"

Ick - that's the nastiest looking socket I've seen! The Krone ones I used here look like this:
http://vorbis.demon.co.uk/DSCF5229.JPG
The stickers are for following different wiring regs.
This is my punchdown tool:
http://vorbis.demon.co.uk/DSCF5230.JPG
The layout of the stickers show which wire goes where, and you're right in that the pairs are fed down the centre of the pins then split and fed to each position. The punchdown tool both inserts and clips the wire so it's really worth getting a real one if you can.
Stefek is also right about the sensitivity - up here in the control tower the connection speeds are spot on, but downstairs in the living room it's noticeable slower so I've obviously b0rked something when I was running the cables. Not sure what though - no excessive bends, no cable ties etc.
-- cheers,
witchy/binarydinosaurs
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This helps quite a bit.
The pairs would go
blue    green brown    orange
The tricky bit with this kind of indication is working out which way around the individual wires of a pair go.
If these are the only sockets you are using it dosn't matter if you are consistent. It does become a problem if you are using different sockets/patch panels.

Whatever. Just don't pull the cable tie too tight.
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Usually the socket is marked according to the pair colours.

Get a proper tool, the disposable plastic things arn't much good.

That's how they want to go.

Don't untwist the pairs any more than you have to.

Reasonably easily. Even more so using the proper tool, which has a hook for that purpose.

Sockets, unlike plugs, don't get "used up". The plastic tools, however...
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