Two standards for Ethernet wiring exist: T568A and T568B. Electrically, “A” and “B” are the same and either can be used when terminating Ethernet and making patch cables, just be sure to be consistent. “A” to “A” and “B” to “B”. These patch cables are used to connect end devices to networking equipment, such as a computer to a switch.

T568B is commonly used as the default for patch panels and keystones. Also, numerous switches and networking devices are capable of auto switching Ethernet ports if a crossover cable is used when a straight-through cable should have been used. It is also common to have crossover cables a designated color to avoid confusion.