Twisted pair cables


1. Straight-Through cable
568A standard
1 green s
2 green
3 orange s
4 blue
5 blue s
6 orange
7 brown s
8 brown

where plug head looks like this (from behind)
 _______________
|1 2 3 4 5 6 7 8|
 ---------------
      |___|


2. Cross-over cable

only wires 1 2 3 6 are used
so cross them over
1 - 3
2 - 6
3 - 1
6 - 2

so one head is  
1 green s
2 green
3 orange s
4 blue 
5 blue s
6 orange
7 brown s
8 brown

and the other is
1 orange s
2 orange
3 green s
4 blue 
5 blue s
6 green
7 brown s
8 brown

the plug head orientation the same as above