27 Nov 2022 go for Cat 6a or Cat 8 to futureproof an installation. Cat 5e otherwise good enough for most. Avoid Cat 7.

Table of Contents

Standards
- Cat 5
  - Cat 5e
- Cat 6
Cat 6a
- Cat 7
- Cat 8
What is a crossover cable?
Best Brands
Resources
- DIY Smart Home Pre Wire Guide
- How to choose an Ethernet cable

Standards

Cat 5

Any cable with standard below 5e should be dismissed - too old.

Cat 5e

Cat 5e is currently the most commonly used cable, mainly due to its low production cost and support for speeds faster than Cat 5 cables.

The “e” in Cat 5e stands for “enhanced.” There are no physical differences between Cat 5 and Cat 5e cables. However, manufacturers build Cat 5e cables under more stringent testing standards to eliminate unwanted signal transfers between communication channels (crosstalk).

Cat 6

Category 6 cable (Cat 6) is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Cat 6 must meet more stringent specifications for crosstalk and system noise than Cat 5 and Cat 5e. The cable standard specifies performance of up to 250 MHz, compared to 100 MHz for Cat 5 and Cat 5e.[1] Whereas Category 6 cable has a reduced maximum length of 55 metres (180 ft) when used for 10GBASE-T, Category 6A cable is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100-metre (330 ft) maximum distance as previous Ethernet variants.

https://en.wikipedia.org/wiki/Category_6_cable

The “a” in Cat 6a stands for “augmented.”

Cat 6a

The “a” in Cat 6a stands for “augmented.” Cables based on this standard are a step up from Cat 6 versions by supporting twice the maximum bandwidth. They’re also capable of maintaining higher transmission speeds over longer cable lengths. Cat 6a cables come shielded, and the sheathing — which is thick enough to eliminate crosstalk — makes for a much denser, less flexible cable than Cat 6.

Cat 7

Avoid. Better than Cat 6 but uses proprietary connectors with some backward compatibility, but not fully compatible. So hardware compatibility issues might arise.

Cat 8

This standard promises a maximum frequency of 2,000MHz and speeds of up to 40Gbps at 30 meters. That high frequency also requires shielding, meaning you’ll never find unshielded Cat 8 cables. Even more, Cat 8 supports two connectors. Thus it only allows for three connected cables with a combined length of 30 meters.

What is a crossover cable?

A crossover cable is a type of Ethernet cable that is used to connect two devices directly to each other. It is called a crossover cable because it has the transmit and receive wires "crossed over" at one end of the cable. This allows the two devices to communicate with each other directly, without the need for a network switch or router.

Unlike an Ethernet cable, crossover cables have specific wiring designed with a reversed path for signal transmission.

Crossover cables work best for direct networking. The crossover wiring model involves a special wiring system for direct networking. It allows you to conjoin two intermediate devices without a switch or router in between.