Making Cable Facts

Twisted pair cables remain one of the primary ways that computers connect to a network. The table below illustrates both straight-through and crossover cable configurations.

Cable	Description
Straight-through	Computers connect to the network through a hub or switch with a straight-through cable. There are two standards for creating straight-through cables: T568A--To use this standard, arrange the wires from pins 1 to 8 in each connector in the following order: GW, G, OW, B, BW, O, BrW, Br. T568B--To use this standard, arrange the wires from pins 1 to 8 in each connector in the following order: OW, O, GW, B, BW, G, BrW, Br. It doesn't matter which standard you use, but once you choose a standard, you should do all your cables that way to avoid confusion during troubleshooting.
Cross-over	Computers can connect directly to one another using a crossover cable. The easiest way to create a crossover cable is to arrange the wires in the first connector using the T568A standard and arrange the wires in the second connector using the T568B standard.

Ethernet specifications use the following pins (Tx is a pin used for transmitting and Rx is a pin used for receiving):

Pin 1: Tx+
Pin 2: Tx-
Pin 3: Rx+
Pin 4: Unused
Pin 5: Unused
Pin 6: Rx-
Pin 7: Unused
Pin 8: Unused

Be aware of the following when making cables for Ethernet:

Cat 5/5e/6 cables come with wires that have solid cores or stranded cores. Use solid core cables for longer runs inside walls or the ceiling; use stranded wires for drop cables where flexibility and frequent movement occurs.
There are different connectors rated for solid or stranded core wires; be sure to use the correct connector type.
To reduce crosstalk, keep the pairs twisted as much as possible right up to the connector.
Making Cat 6-compliant cables is difficult; if you do not add the connectors exactly right, the cable will only function as a Cat 5 cable. In most cases it would be easier to buy cables of the correct length than to try and make your own.