Crossover Cable Wiring: What It Is and How to Wire It

When setting up a direct connection between two computers or networking devices of the same type, you may need a crossover cable instead of a standard Ethernet cable. In this guide, we explain what a crossover cable is, when to use it, and how to wire one correctly using the T568A and T568B standards.

crossover cable wiring

🔌 What Is a Crossover Cable?

A crossover cable is a type of Ethernet cable where the transmit and receive signal pairs are swapped, allowing two similar devices (e.g., two computers) to communicate directly without a hub, switch, or router.

🔄 In a crossover cable, TX (transmit) pins on one end are connected to RX (receive) pins on the other.

🧰 When to Use a Crossover Cable

Crossover cables are typically used for:

• Connecting two PCs directly

• Linking two network switches or hubs without uplink ports

• Networking two routers or modems in peer-to-peer setups

• Transferring files between devices without internet access

Note: Many modern devices support Auto MDI-X, which auto-detects crossover, making dedicated crossover cables less common today—but they’re still useful in older or specific environments.

🧵 Crossover Cable Wiring Diagram (RJ45)

Crossover cables follow different standards on each end:

Other wires (pins 4, 5, 7, 8) are typically unused for 10/100 Mbps Ethernet and are wired straight through.

🛠 Only pins 1, 2, 3, and 6 are swapped to create the crossover.

📷 Visual Wiring Reference:

🧪 Testing a Crossover Cable

To verify your crossover cable:

• Use a cable tester to check continuity

• Ensure pins 1↔3 and 2↔6 are properly swapped

• Confirm the devices establish a connection when plugged in

🌐 Where to Buy Crossover Cables

You can make one yourself or buy pre-terminated Cat5e/Cat6 crossover patch cables. Look for:

• RJ45 UTP/FTP Cat5e or Cat6 cables

• Clearly labeled “crossover” (not straight-through)

• Verified compatibility with the network speed (10/100/1000 Mbps)

🧭 Summary: Crossover vs Straight-Through

📞 Need Bulk Ethernet Cable for Custom Wiring?

At TOT Wire & Cable, we provide:

• Bulk Cat5e/Cat6 UTP & FTP cables

• Custom crossover wiring and pre-terminated patch cables

• OEM services for IT infrastructure and network installers

👉 Contact us for pricing or custom RJ45 wiring needs.