CAT5 wiring A or B? - Networking - Spiceworks - Page 3 Mar 20, 2014Mar 20, 2014 at 12:20 UTC. 568B is standard for data connections. 568A is standard for voice connections. Electrically they are the identical, the pair colors are just different. There's really no functional difference, only thing is, wiring a run or jumper with one end -A and the other -B creates a crossover cable. [SOLVED] RJ45 Type A + Type B? - Networking - Spiceworks Feb 21, 2016T568A and T568B are totally compatible. The only problem arises when one end is wired A and the other end of the same cable is B, you can mix patch cables (e.g. use a T568B patch cable on a T568A network drop) as the only difference is colors. It when each end of the same cable follows a different standard that is when you would have trouble with this. Network Cable Connectors | Cat5, Cat6, RJ45 & Fiber Optics The main similarity between T568A and T568B is that they both provide wiring schemes for terminating twisted-pair copper network cable (CAT cables) to 8-position RJ45 jacks and connectors.