Category 5 Standard Wiring.
10BaseT and 100BaseT networks use Cat5 twisted pair cable and RJ45 connectors to join computers to hubs or switches. This post details how to wire the connectors.
Straight (standard) Cables
These are the cables linking a computer to a hub.
Hold the RJ45 connector with the pins to the top, and the catch facing away from you. Pin 1 is the left-hand most pin, and pin 8 is the right-hand most pin. The cables are wired straight through Pin1-Pin1 … Pin8-Pin8 with the following colour scheme.
| Pin Number | Wire Colour |
|---|---|
| 1 | White/Orange |
| 2 | Orange |
| 3 | White/Green |
| 4 | Blue |
| 5 | White/Blue |
| 6 | Green |
| 7 | White/Brown |
| 8 | Brown |
Crossover Cables
These cables are used to link two hubs together where an uplink port is not available or two computers directly together. In basic terms they cross over the transmit and receive lines, much like a null-modem cable. Again, hold the RJ45 connector with the pins to the top, and the catch facing away from you. Pin 1 is the left-hand most pin, and pin 8 is the right-hand most pin.
| Connector 1: Pin Number | Wire Colour | Connector 2: Pin Number |
|---|---|---|
| 1 | White/Orange | 3 |
| 2 | Orange | 6 |
| 3 | White/Green | 1 |
| 4 | Blue | 4 |
| 5 | White/Blue | 5 |
| 6 | Green | 2 |
| 7 | White/Brown | 7 |
| 8 | Brown | 8 |