Straight Through Cable – Wiring, Color Codes & When to Use It

A straight through cable is the most common type of Ethernet cable used in networking. It gets its name because the wiring pattern on one end of the cable is exactly the same on the other end — the pins line up in a “straight” order. This simple wiring style makes it the standard choice for connecting different types of devices, such as a computer to a switch, a router, or even a printer.

In this guide, we’ll explain:

• What a straight through cable is (and how it works)
• Wiring standards and color codes you should know
• When to use a straight through cable vs a crossover cable
• Practical examples and FAQs for easy understanding

By the end, you’ll know exactly how straight through cables work, what they’re used for, and how they differ from crossover cables.

What is a Straight Through Cable?

A straight through cable is a type of Ethernet cable where the wiring order on both ends is identical. In simple terms, pin 1 connects to pin 1, pin 2 to pin 2, and so on up to pin 8. Because the wires run “straight through” without swapping positions, this cable ensures a direct one-to-one connection.

Key Features of a Straight Through Cable

• Identical pin layout on both connectors
• Uses either T568A or T568B wiring standard (must match on both ends)
• Typically built with Cat5e, Cat6, or Cat6a Ethernet cable
• Supports speeds from 10 Mbps to 10 Gbps, depending on cable type

What Does It Do?

The straight through cable is mainly used to connect different types of networking devices, such as:

• Computer → Switch
• Switch → Router
• Computer → Printer
• Access Point → Router

This makes it the default choice for most home and office networks.

Straight Through Cable Color Code & Color Coding

A straight through cable follows a standard wiring pattern to ensure that both ends of the cable match exactly. This is where the color code comes in. The color coding helps identify which wire goes into which pin, keeping the connection consistent and error-free.

Wiring Standards: T568A and T568B

Ethernet cables use two main wiring standards:

• T568A – Green pair starts on pins 1 and 2.
• T568B – Orange pair starts on pins 1 and 2.

Both are correct, but the important rule for a straight through cable is that the same standard must be used on both ends. For example:

• If you start with T568B on one side, the other side must also follow T568B.
• If you use T568A on one side, the other side must also follow T568A.

This identical pattern keeps the cable “straight through.”

Straight Through Cable Color Order (T568B Example)

The most widely used standard today is T568B. Here’s the color order from pin 1 to pin 8 on both connectors:

1. White/Orange
2. Orange
3. White/Green
4. Blue
5. White/Blue
6. Green
7. White/Brown
8. Brown

Since both ends are identical, the wiring flows straight through — hence the name.

Why Color Coding Matters

The color coding ensures that each pin carries the correct signal (transmit or receive). If the order is mixed up, the cable won’t work. Following the correct straight through cable color code is essential for stable connections in home and office networks.

When to Use a Straight Through Cable

Use a straight through cable when connecting different types of devices (e.g., computer ↔ switch, router ↔ switch, computer ↔ printer). It is the default Ethernet cable in most networks.

Common Uses of Straight Through Cable

• Computer to Switch – the most common use in offices and homes.
• Computer to Router – to access the internet through your network.
• Router to Switch – to expand network connections.
• Computer to Printer (Network Printer) – for direct Ethernet printing.
• Access Point to Router/Switch – to provide Wi-Fi connectivity.

Why Use Straight Through Instead of Crossover?

• Compatibility: Straight through cables are supported by almost all modern devices.
• Reliability: Less chance of wiring mismatch or errors.
• Default Choice: Unless your setup specifically requires a crossover cable, always start with a straight through cable.

Straight Through Cable vs Crossover Cable

The main difference between straight through and crossover cable lies in the wiring. Straight through cable has the same pin order on both ends and is used for connecting different devices. While crossover cable has swapped wiring on one end and was traditionally used to connect similar devices, though it’s rarely needed today.

1. Wiring Pattern

Straight Through Cable: The wiring sequence is identical on both ends (pin 1 → pin 1, pin 2 → pin 2).

Crossover Cable: The transmit and receive pairs are swapped on one end (pin 1 → pin 3, pin 2 → pin 6).

This wiring swap in a crossover cable allows two similar devices to talk directly.

2. Device Connection Type

Straight Through Cable: Used to connect different types of devices (e.g., computer ↔ switch, router ↔ switch).

Crossover Cable: Used to connect similar devices (e.g., computer ↔ computer, switch ↔ switch).

3. Modern Relevance

Straight Through Cable: Still the default Ethernet cable for most home and office networks.

Crossover Cable: Rarely needed today because modern devices support auto-sensing (auto MDI-X), which automatically adjusts wiring internally.

Straight Through Cable and Crossover Cable – Key Differences

Frequently Answered Questions

1. What is a straight through cable?

A straight through cable is a type of Ethernet cable where the wiring pattern is the same on both ends. It is used to connect different devices, such as a computer to a switch or a router.

2. What is the difference between straight through and crossover cable?

The difference is in the wiring:

• Straight through cable – same wiring order on both ends, used for different devices (e.g., PC ↔ Switch).
• Crossover cable – transmit and receive pairs are swapped on one end, used for similar devices (e.g., PC ↔ PC).

3. When should you use a straight through cable?

Use a straight through cable when connecting different types of devices, such as a computer to a router, a router to a switch, or a computer to a printer. It is the default Ethernet cable for most networks.

4. What is the color code for a straight through cable?

A straight through cable color code follows either the T568A or T568B standard. The most common is T568B, with the pin order:

1. White/Orange
2. Orange
3. White/Green
4. Blue
5. White/Blue
6. Green
7. White/Brown
8. Brown

5. Do you still need crossover cables today?

Not usually. Modern devices support auto-sensing (auto MDI-X), which allows a straight through cable to work even where a crossover cable was once required. As a result, most networks today only use straight through cables.