Cat5 cable is rated at 100 MHz, that is the bandwidth or size of the pipe if you will. However, to meet that requirement they only need to be able to make that work on two pairs, since that is what 10Bt and 100BT ethernet use. Cat5e (enhanced) is also rated only at 100 MHz, though you may find Cat5e cable boasting higher bandwidths (250-350Mhz). For Cat5e, they have to make it fly at 100 Mhz on all four pairs. Essentially it is just a bit enhanced for future technologies. Cat6 was recently voted on and ratified (finally) by the standards committee, and pending final approval should be done very soon. Cat6 provides a cable designed to operate up to 200 MHz and tested at 250 Mhz.
Keep in mind that it is not just the wire, but the connectors, terminations, patch cords, and all that contribute to the overall performance. Just to show you how much better the Cat6 stuff is, here are a few stats given by Fluke Networks.
They tested Cat6 wire and hardware at 100 Mhz and compared it with Cat5 wire and hardware at 100 MHz. The NEXT was 337% better on Cat6, PSNEXT was 216% better on Cat6, other required network test parameters were from 58% to 104% better on the Cat6. The end result of all that is that you have more headroom on your network, a better chance of making whatever it is you want to go as fast as you need.
As far as cable construction, twist rate of the wire is one factor in achieving the end result. Depending on the manufacturer, some have chosen to add internal dividers in the wire jacket, melt the pair jackets together, etc.
Hope that helps. Check out
it should be up soon, it is dedicated to this whole category testing thing and is provided by Fluke.
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
