Glen Turner (vk5tu) wrote,
Glen Turner

Coloured UTP cables considered harmful

The rainbow hurts my eyes

One colour for links to client computers, another colour for links to servers, another colour for phones. Sounds like a wonderfully organised network.

Don't do it.

The reason is stocking. You want a good stock of UTP cables. Ten or twenty in lengths from 0.5m to 3m in every increment available (typically 0.5m), then 5m, 10m, 15m.

It is much more important to use the correct length cable than it is to have some colour scheme. The more colours you have, the less stock of each colour in all the lengths you will carry.

Why is it important? Cable control. If you stock every length the average slack you need to dispose of in a cabinet is 25cm, the worst case is 49cm. If you are missing just one size the average becomes 75cm and the worst case becomes 149cm, both of which are a significant amount of cable to route out of the way. You do that more than one or twice then your cabinet is a cabling disaster zone. You'll never be able to remove a cable easily, which means you won't, which will snowball over the years.

Consider one exception: cross-over cables. Make these some non-red noticeable colour (red has a special meaning and you shouldn't be using it in patch cabinets). I use pink. You need one length: 0.5m. You need one type: the "gigabit ethernet four-pair crossover". To use the cable plug it into the interface of the equipment, attach a Cat6 through-connector, and then cable using your typical patch leads. Why as long as 0.5m? Because that is enough to clear the equipment and place the through-connector outside of the equipment's own cable control.

Coloured patch leads indicate that you lack sufficient records of your cabling plant and sufficient labelling to audit those records against the plant. If you feel the need for coloured cabling "to prevent error" then I suggest you look to improving your record-keeping.

Tags: rant
  • Post a new comment


    default userpic

    Your reply will be screened

    Your IP address will be recorded 

    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.