[PDF] Color Codes for RJ-45 Ethernet Plug - ZetaTalk The jack should either come with a wiring diagram or at least designate pin numbers that you can match up to the color code below. There are two wiring standards for these cables, called T-568A and T-568B. as spec'ed by 568, there are two possible pinouts, called T568A and T568B, that differ only in which color coded pairs are connected Ethernet crossover cable - Wikipedia An Ethernet crossover cable is a crossover cable for Ethernet used to connect computing devices together directly. It is most often used to connect two devices of the same type, e.g. two computers (via their network interface controllers) or two switches to each other contrast, straight through patch cables are used to connect devices of different types, such as a computer to a network switch.