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Re: Cable Colors - A Standard
George Imburgia wrote:
There's a standard; ANSI/TIA/EIA 606A http://www.flexcomm.com/library/606aguide.pdf
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.
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.