10/100 BaseT Cables

Description

Ethernet cables are confusing to many people. Not only is the wire order strange, but specifics are hard to come by in user readable form. Often times even people that are knowledgable forget the order if they haven't done it in a while. It is not obvious.

To make a 10/100BaseT cable you need two RJ45 connectors, category 5 networking cable, wire cutters, and a special tool that affixes the RJ45 connector (it looks like a big phone jack plug) on to the wire. This tool is called a crimper.

An important note:
The wires in the network cable are color coded. For instance: green and green stripe form a twisted pair. A twisted pair need to used together, it has to do with the electrical characteristics of magnetic fields, suffice to say, make sure you use the colors as specified in the tables, they are important.

Standard

1 orange stripe------------orange stripe

2 orange-------------------orange

3 green stripe-------------green stripe

4 blue---------------------blue

5 blue stripe--------------blue stripe

6 green--------------------green

7 brown stripe-------------brown stripe

8 brown--------------------brown

Cross-over (hub to hub, PC to PC)

Type 1

1 orange stripe------------green stripe

2 orange-------------------green

3 green stripe-------------orange stripe

4 blue---------------------blue

5 blue stripe--------------blue stripe

6 green--------------------orange

7 brown stripe-------------brown stripe

8 brown--------------------brown

Type 2

1 orange stripe------------green strip

2 orange-------------------green

3 green stripe-------------orange strip

4 blue---------------------brown

5 blue stripe--------------brown strip

6 green--------------------orange

7 brown stripe-------------blue stripe

8 brown--------------------blue

Why type #1 and type #2 cross-over?

Documentation for making a cross-over cable indicate that type #1 is the correct wiring, but, type #2 has been seen in the field as well. So what does this mean? I guess not much because pins 4,5,7, and 8 are documented as carrying signals, but do not seem to make a difference.