RJ45 Ethernet Cable (Cat 5e Cat 6) – Pinouts and Colour Guide

A Comprehensive Guide to RJ45 Ethernet Pinouts and Colours. Understanding Straight-Through and Crossover Cables for Ethernet Networks.

The RJ45 connector is a standardized interface used in Ethernet networking. RJ45 connectors are commonly used to terminate twisted-pair cables, such as CAT5e and CAT6, and are essential for creating reliable wired local area networks. Ethernet cable is the typical blue cabling you see connecting different devices to the wall, switch or patch panel. Ethernet Cable has 8 wires or 4 wire pairs. Each wire and pair are identified by Ethernet cable colours. This guide provides detailed information on RJ45 Ethernet pinouts and colours and their correct order to ensure a reliable connection. It covers both straight-through cables and crossover cables on both industry standards.

Understanding RJ45 Connectors

RJ-45 connectors or RJ-45 Plugs have eight pins, which are used to terminate the individual pairs of wires inside an Ethernet cable. These modular connectors are typically crimped onto the end of the cable with a specialised crimping tool, allowing for secure connections and data transmission to network devices like routers, switches, and computers.

Pinout Standards

There are two main wiring standards for RJ-45 connectors: T568A and T568B. These standards define the pinout configuration for the wires within the cable. While both standards are widely used, T568B is more common in the United States whilst in Australia we typically use T568A. You might find many prebuilt cables you get with equipment are wired for T568B, this doesn’t matter though, it doesn’t matter what wiring scheme is used they will all work the same.

T568A Wiring Standard – The preferred Standard for Australia

T568B Wiring Standard

Straight-Through Cables

Straight-through cables are the the most common cables you will create and are the standard for Ethernet connections. Straight-through network cables are the ones used to connect all your peripherals or network devices , such as a computer, printer, modem or router to a centralised switch. These cables are typically referred to as “Patch Cable” or “Patch Cords” as they patch the network devices into a switch or wall plug. In a straight-through cable, both ends of the network cable follow the same wiring standard, either T568A or T568B.

Uses of Straight-Through Cables

• Connecting a computer to a network switch or hub
• Connecting a router to a modem
• Connecting a network switch to a router

Wiring a Straight-Through Cable

To wire a straight-through cable, simply align the wires according to the chosen standard (T568A or T568B) on both ends of the cable. This ensures that pins 1 through 8 on one end match pins 1 through 8 on the other end.

Crossover Ethernet Cable

Crossover cables are used to connect similar devices directly, such as connecting two computers or two network switches. In an Ethernet crossover cable, one end follows the T568A standard, while the other end follows the T568B standard. This configuration allows the transmit and receive signals to be correctly aligned.

Uses of Ethernet Crossover Cables

• Connecting two computers directly without a switch or hub
• Connecting two network switches directly
• Connecting two routers directly

Wiring a Crossover Cable

To wire a crossover cable the only difference is to use the T568A standard on one end and the T568B standard on the other end. This creates the necessary crossover of the transmit and receive pairs.

Pinout Colour Coding Comparison for Crossover Cables

• Pin 1 (T568A: White/Green) connects to Pin 3 (T568B: White/Green)
• Pin 2 (T568A: Green) connects to Pin 6 (T568B: Green)
• Pin 3 (T568A: White/Orange) connects to Pin 1 (T568B: White/Orange)
• Pin 4 (T568A: Blue) connects to Pin 4 (T568B: Blue)
• Pin 5 (T568A: White/Blue) connects to Pin 5 (T568B: White/Blue)
• Pin 6 (T568A: Orange) connects to Pin 2 (T568B: Orange)
• Pin 7 (T568A: White/Brown) connects to Pin 7 (T568B: White/Brown)
• Pin 8 (T568A: Brown) connects to Pin 8 (T568B: Brown)

Conclusion

Understanding RJ45 Ethernet pinouts and colors is essential for anyone working with network cabling. By following the correct wiring standards for straight-through and crossover cables, you can ensure reliable and efficient network connections. Whether you are setting up a home network or managing a large-scale enterprise system, this knowledge will help you create robust and effective networking solutions.