As the title says, I'm curious of the pairs need to be twisted? If so, How does this help? What does it do? If they are not twisted what can happen?

Reason I ask is because I've been working on that little project of my home network, and I am having some trouble getting the cable to validate (With a cable tester). I have 1000FT of untwisted cabling. Is this a problem?

If I remember my years of electrician work, it's a matter of electric noise.
Having the pairs lying flat next to each other will generate magnetic fields that will cause noise and distort signal.
A bit like echo in a canyon, the pair will have their signal that overlap to the next via an electromagnetic effect.

The more they are next to another, the stronger the magnetic field.
By twisting them, we reduce the total length that generate those magnetic fields, and thus that echo.

As cat6 is usually associated with gigabyte networks, I'd say it's rather important to avoid as much as you can interferences.

PS: Looking at documentation about it, I now know this effect is called crosstalk:
http://en.wikipedia.org/wiki/Crossta...electronics%29

AND

The maximum allowed length of a single run of structured wiring in Cat5, Cat5e or cat6 is 92 metres (302 feet), this is to allow for a maximum length of patch lead of 2x4m to bring the total length of cable to 100m ~328ft

Well, From what I understand, you would still be able to get a valid cable (At least electronically) but i'm having a problem with that. I follow pattern A, and crimp it using a RJ-45 crimpper..But I still cant get a signal from any of the connections (8)

Best I have ever manged to run Cat5 cabling is a little over 250m (~750ft) BUT that was with a 24v DC signal source, and the volt drop on that was 5.5v

The output voltage for IEE802.5 is a maximum of 2.8v peak differential (into 100 ohms) and it runs nominally at 2.5v peak.

So while it would possible to get a sound electrical connection at 1000ft the signal source will need to be around 27volts, over 10 times the output from network devices.

The gauge of the cable is a factor in the length as well. And also whether it is solid or stranded, shielded or unshielded. There are many factors to consider when determining cable length.

CAT5, 5e & CAT6 are 24SWG (23AWG) regardless of core construction.

There are not "many factors" determining cable length. Volt drop or I²R loss is basically the ONLY factor that will decide the maximum allowable length for ANY purpose.

Originally Posted by chrishirst

CAT5, 5e & CAT6 are 24SWG (23AWG) regardless of core construction.

There are not "many factors" determining cable length. Volt drop or I²R loss is basically the ONLY factor that will decide the maximum allowable length for ANY purpose.

Never bought cable from Hong Kong then? J/K!

Sorry, but voltage isn't the only factor. Signal loss and interference is also important when considering cable length.

As signal strength is measured in volts (or sub-divisions of) - signal loss is voltage drop.

Interference is NOT related to cable length. The environment the cable is running through and the quality of screening from external influence affects the interference. Six inches of poorly screened or poorly installed cable could suffer more from interference than ten kilometres of correctly laid and screened cable.