O'Reilly logo

Power Over Ethernet Interoperability Guide by Sanjaya Maniktala

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Twist Rate and Wire Diameter
An extremely important characteristic of a twisted pair is related to the basic question: How twisted is it? Cable categories have been defined in the standards, and these eventually relate directly to a certain twist rate, or twists per unit distance (distance is measured in inches or feet, for example). We do not need to go into too much networking detail here, but it is good to keep in mind that the greater the twisting, the better the performance of the cable in general.
For PoE, the twist rate is not of any direct concern, except perhaps in some esoteric system-design matters as discussed later. Because, in PoE, we are essentially concerned only with the DC resistance of the cables, not its reactive parasitic ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required