Making Ethernet Cables And other cable related wisdom. Ethernet is based on Cat5 cable. This consists of 4 pairs, for a total of 8 lines. Each pair is twisted together in the cable, and each pair has a different twist structure. Hence why it is often called shielded / unshielded twisted pair (STP / UTP). Its vital not to disturb the twists on the cable to much - when working with cat5 only un-strip as much of the cable as you need.There are two patterns for cat5, A and B. Because of the twisting you must use one of these. For a normal cable wire both ends in the same way, for a crossover cable wire one end a A, and one end as B. These are: ...