Cable Colors

I find this interesting - as lately i've found that keeping a supply of
various lengths of commercially-manufactured leads of appropriate colours,
etc, has been a better long term solution than home-made leads. Perhaps I
just suck at crimping cables, but I prefer to use commercially made (and
tested) leads.

The drawback, of course, is when you run out of the right length and wind
up using longer cables, which in turn makes cable management a bit of a

Maybe we just wire in more tight places, but I find that it's somewhat
difficult to deal with more than about three excess inches when doing
in-frame wiring. I don't want to have to deal with excess.

It is (maybe was? haven't looked in several years) difficult to find
someplace that will manufacture quality Cat6 molded cords in arbitrary
lengths in relatively small quantities. There's a million places that
will be happy to custom-make you Cat6 crimped or crimped+booted cables,
but if I wanted that, I could hire a monkey to make them for us at a
cheaper price. If I'm going manufactured prefab, I want molded.

Given that, and given that the shop (where we could maintain significant
stock) is not always convenient (for ex., equipment in Ashburn, shop in
Milwaukee) the easier solution has typically been to keep a few 1000'
spools and make cables to exact length as needed.

... JG

Perhaps it's because my wiring background, such as it is, runs more to
video than networking...

but doesn't *anyone* put service loops in anything anymore?

-- jra

There's a standard;


Page 23

Informative and what I was looking for..

George Imburgia wrote:

There's a standard;

Here in Australia there's no standard for colours of data communications
patch cables.

But there are some non-data communications standards for fixed
cable colours. In particular, fire system sensors must use red;
the use of cream is reserved for telephony; and fixed electrical
cables must be white.

To minimise error I avoid those colours for patch cables
(ie, non-fixed cables). This is prudent anyway, as under the
Wiring Rules simply tying down a patch lead with a cable tie
is enough to turn it into a fixed cable.

I've found that it's more important to have a ready supply of
cable lengths (say 0.5m increments) and labels than to have
colours. That avoids a mess developing in the first place that
might need colour coding to sort out. We use blue, simply
because it's the most readily available colour.

The only cable which really needs a special colour is one
which doesn't connect all eight pins in sequence.

To avoid stocking many lengths of cross-over cables, we use
a 0.6m crossover cable and a Cat6 joiner. We colour these
pink -- it's noticeable and Real Men sysadmins don't steal them.

A useful tool is a audio cable tracer. When disconnecting
a PC you attach the signal injector. You then use the other
half of the tool to identify the cable (it buzzes when near).
This allows the patch cables to be pulled with certainty
rather than left in the rack just in case it attached to some
other host and you fear causing an unplanned outage.

Also I've found that many cabling messes occur because the
installer had no alternative. There was simply no cableway
that wasn't congested. For high-density routers I've found
that about 1/3rd of the rack is given over to cable patch
panels and ring runs. About two racks in ten (ie, one optical,
one UTP) need to be given over to just inter-rack patching
and I'd encourage a specialist-built patch rack for that purpose.

A rack full of PCs requires about 0.8m of available tray down the
side of the rack to tie down the patch leads and other cables.
Again, that huge amount of tray isn't usually provided, can't
be added afterwards, and the installer has no choice but to do
poor work if there's nothing to tie cables to.

We ban non-fixed cabling between our racks, which means that
patch cables only run within a rack. This simplifies things
considerably. Fortunately, we've got the fiber density to
racks to justify that design. I've noticed a considerable
fall in the price of pre-assembled optical patch panels,
so it's well worth looking at the prices even at low densities
of cables to see if they fallen enough to make a fixed
cabling system worthwhile. It's not like alternative -- those
gutters used to pull optical patch leads between racks -- are
cheap so I've expect the prices to cross at some stage in the
next few years.

Cheers, glen

You whack on one of these things when there's still active gear on the end?

This one is plenty safe to stick on a live cable, plus it works a whole lot
better than the old analog ones: