Not all Ethernet cables are created equal. What's the difference, and how do you know which you should use? Let's look at the technical and physical differences in Ethernet cable categories to help us decide.

Ethernet cables are divided into sequentially numbered categories ("cats") according to different specifications; sometimes the category is updated with further instructions or testing standards (eg 5e, 6a). These categories allow us to easily understand which type of cable is required for a particular application. Manufacturers are required to adhere to these standards, which makes our lives easier.

What is the difference between these categories? How do you know when to use unshielded, shielded, stranded or solid cable?

technical difference

Differences in cable specifications are not as easy to see as physical variations; so let's see what each category does and doesn't support. Below is a reference chart when selecting a cable for your application based on the category's criteria.

As the category number increases, so does the speed and Mhz of the wire. This is no coincidence, as each category brings with it more stringent testing to eliminate crosstalk (XT) and increase isolation between wires.

That doesn't mean your experience is the same. You can physically achieve 1 Gb speeds with Cat-5 cable, and I've personally used cables longer than 100 meters, but since the standard hasn't been tested for it, you may get different results. Just because you have Cat-6 cable, doesn't mean you also have 1 Gb internet speeds. Every connection in the network needs to support 1 Gb speed, and in some cases the connection needs to be told in software to use the available speed.

Category 5 cables have been revised and largely replaced by Category 5 Enhanced (Cat-5e) cables, which do not change any of the physical characteristics of the cable, but instead adopt stricter crosstalk testing standards.

Category 6 was amended by the expanded Category 6 (Cat-6a) to provide a 500 Mhz communications test (compared to Cat-6's 250 Mhz). Higher communication frequency eliminates alien crosstalk (AXT), allowing longer range of 10 Gb/s