How to Terminate Ethernet Cables | RJ-45 Wiring Scheme The jack should have a wiring diagram or designated pin numbers/colors to match up to the color code below. When wiring a jack or an RJ-45 plug, remember to keep the “twist” as close as possible to the (jack or plug) receptacle. This will insure compliance with Ethernet wiring standards. Specification T-568BAuthor: Christina Hansen How to Make a Category 5 / Cat 5E Patch Cable The only difference between 568A and 568B wiring is that pairs 2 and 3 (orange and green) are swapped. If you are unsure which one to use then you should go with the 568B diagram. It is the 568B diagram that we demonstrate in this tutorial and the 568A wiring is shown in the diagrams below mainly for illustration.