In a straight-through cable, wires 1,2,3,4,5,6,7 and 8 at one end of the cable are still wires 1~8 at the other end. In a crossover cable, the wires of 1,2,3,6 are reversed so that wire 1 become 3 at the other end of the cable, 2 becomes 6, and so forth.
To determine which wire is wire 1, hold the RJ-45 cable tip with the spring clip facing towards the ground and the end pointing away from you. The copper wires exposed upwards to your view. The first wire on the far left is wire 1. You can also refer to the illustrations and charts of the internal wiring on the following page.
Straight-Through Cabling
| Figure 3 |
Wire | Becomes |
1 | 1 |
2 | 2 |
3 | 3 |
6 | 6 |
Cross-Over Cabling
| | Figure 4 |
| Wire | Becomes |
| 1 | 3 |
| 2 | 6 |
| 3 | 1 |
| 6 | 2 |
Note: | To prevent loss of signal, make sure that the length of any twisted-pair connection does |
| not exceed 100 metres. | |
42 | NP2500 24-Port 10/100 PoE + 2-Port 10/100/1000 WebSMART Switch User Guide |
| YML842 Rev1 |
