Ethernet Cables, How They Work and How to Choose the Right One

A look at which Ethernet cables are on wired networks

An Ethernet cable is a common type of network cable used with wired networks. Ethernet cables connect devices such as PCs, routers, and switches within a local area network.

These physical cables are limited by length and durability. If a network cable is too long or of poor quality, it won't carry a good network signal. These limits are one reason there are different types of Ethernet cables that are optimized to perform certain tasks in specific situations.

What an Ethernet Cable Looks Like

An Ethernet cable resembles a traditional phone cable but is larger and has more wires. Both cables share a similar shape and plug, but an Ethernet cable has eight wires, while phone cables have four. Ethernet cable connectors are also larger.

Illustration showing an ethernet cable and a phone cable side-by-side

Ethernet cables come in many different colors, but phone cables are usually grey.

Ethernet cables plug into Ethernet ports, which are larger than phone cable ports. An Ethernet port on a computer is accessible through the Ethernet card on the motherboard. This port is usually on the back of a desktop computer, or on the side of a laptop.


What is an Ethernet Cable?

How to Choose an Ethernet Cable

Ethernet cables support one or more industry standards including Category 5 and Category 6. Most technicians refer to these standards as CAT5 and CAT6, respectively. Because of this, many online stores that sell network cables use this abbreviated language as well.

Types of Ethernet Cables

Ethernet cables are manufactured in two basic forms:

  • Solid Ethernet cables offer slightly better performance and improved protection against electrical interference. They're also commonly used on business networks, wiring inside office walls, or under lab floors to fixed locations.
  • Stranded Ethernet cables are less prone to physical cracks and breaks, making them more suitable for travelers or in-home network setups.

A crossover cable is a type of Ethernet cable that connects two computers to each other. By contrast, most Ethernet cables connect one computer to a router or switch.

Things to Consider When You Buy

A single Ethernet cable has a maximum distance capacity, meaning the cable has an upper limit as to how long it can be before there is a signal loss (called attenuation). This problem results because the electrical resistance of a long cable affects performance.

Both ends of the cable should be close enough to each other to receive signals quickly, and far enough away from outside electrical interference to avoid interruptions. However, this precaution doesn't limit the size of a network, because hardware like routers or hubs can join multiple Ethernet cables together on the same network. This distance between the two devices is called the network diameter.

The maximum length of a CAT5 cable, before attenuation occurs, is 100m (328ft). CAT6 can go up to 700 feet. Ethernet cables can be longer but may suffer from signal loss, especially if they pass near large electrical appliances.

A short cable may suffer from signal reflection. However, some people have reported no problems with cable lengths as low as 4 inches.

Different types of RJ-45 connectors serve different purposes. One type, designed for use with stranded cables, is incompatible with solid cables. Other types of RJ-45 connectors may work with both stranded and solid cables.

Alternatives to Ethernet Cables for Computer Networking

Wireless technologies such as Wi-Fi and Bluetooth have replaced Ethernet in many home and business networks. Most tablets and other mobile devices don't have a network port.

These wireless technologies are advantageous if the cable runs outside or in locations with a heightened risk of wire damage.

  • How do I connect an Ethernet cable?

    Look for an Ethernet port on your device. It has a square build that fits the standard RJ45 connector. Insert one end of the cable into an available port in your computer and connect the other end to a router or another network device.

  • Which type of Ethernet cable do I need?

    If your network supports Gigabit Ethernet, you may want to select Cat5e or Cat6 cables over prior generation Cat5 cables.

  • Can I run Ethernet cables outside?

    Yes, you can wire Ethernet cables outside between buildings or over exterior walls. Choose cables with a protective coating or weatherproof wires explicitly designed to provide more durability against the elements.

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