Identifying T568A and T568B
2. Spotting the Difference
Okay, so how can you tell if a cable is wired to T568A or T568B? It's all in the color code! The easiest way to identify the standard is to look at the order of the wires when viewed from the front of the RJ45 connector (with the clip facing away from you). This is when looking at the pins 1 through 8. The best way to keep these clear is to remember the difference is which order the Green and Orange pairs are. For T568A Green will come before Orange, and T568B, Orange will come before green!
T568A: The wire order is white/green, green, white/orange, blue, white/blue, orange, white/brown, brown. Notice the green pair comes before the orange pair.
T568B: The wire order is white/orange, orange, white/green, blue, white/blue, green, white/brown, brown. Here, the orange pair takes the lead.
If you are looking at a cable that you already have, and need to determine the type, grab a magnifying glass, and your glasses. Make sure you can see the wires clearly. It also helps to compare to a wiring diagram side by side. Remember to view the cable from the end of the connector, with the pins facing up.
