[rescue] Cable testers

Phil Stracchino phils at caerllewys.net
Sat Apr 23 18:18:03 CDT 2016

On 04/23/16 17:38, Mouse wrote:
>>> I'm curious: does happen to anyone know what property testers
>>> capable of detecting split pairs are actually testing for?
>> In the simplest terms, a conductor goes to the wrong pin.  A common
>> example I've seen made by the unaware or inattentive:  Solid-green
>> and solid-blue, or green/white and blue/white, accidentally swapped.
> Then perhaps I misunderstood.  I took "split pairs" to be a cable that
> is correctly wired as far as DC tests go but which, for example, puts
> one pair on green and white/blue and another on blue and white/green.
> That is, pairs for signaling purposes do not match up with which wires
> are twisted together.
> As a simple example of one, a friend of mine wired up some cables
> thinking the pairs were pins 1/2, 3/4, 5/6, and 7/8 on the 8P8C,
> instead of the actual 1/2, 4/5, 3/6, and 7/8.  His runs were fairly
> short, and they worked at 10Mb, but when he switched to 100Mb they
> stopped working, to his great puzzlement until he learnt the pairing.

Yup.  We are in vehement agreement here.  :)  We're just using different
(even though similar) words to describe it.

  Phil Stracchino
  Babylon Communications
  phils at caerllewys.net
  phil at co.ordinate.org
  Landline: 603.293.8485

More information about the rescue mailing list