Based on recent experience, there are few things more irritating than spending time diagnosing network problems to find out that it was a faulty cable. This short post is designed to act as a pinout guide for terminating Cat 5E cables.
The diagrams below show how to crimp an RJ-45 end in 568-A and 586-B configurations. See the notes below for guidelines and tips.
Cat 5E (568-A)
| Pair | Wire | Pin |
| 1-White & Blue | White & Blue | 5 |
| Blue & White | 4 | |
| 2-White & Green | White & Green | 1 |
| Green & White | 2 | |
| 3-White & Orange | White & Orange | 3 |
| Orange & White | 6 | |
| 4-White & Brown | White & Brown | 7 |
| Brown & White | 8 |
Cat 5E (568-B)
| Pair | Wire | Pin |
| 1-White & Blue | White & Blue | 5 |
| Blue & White | 4 | |
| 2-White. & Orange | White & Orange | 1 |
| Orange White | 2 | |
| 3-White & Green | White & Green | 3 |
| Green & White | 6 | |
| 4-White & Brown | White & Brown | 7 |
| Brown & White | 8 | |
Notes:
- 568-B wiring is the most common method for patching
- There is no difference in connectivity between 568B and 568A cables. Either wiring should work fine on any system.
- For a straight through cable, wire both ends identical.
- For a crossover cable, wire one end 568A and the other end 568B.
- Do not confuse pair numbers with pin numbers. A pair number is used for reference only (eg: 10BaseT Ethernet uses pairs 2 & 3). The pin numbers indicate actual physical locations on the plug and jack.
