Cat5e RJ-45 Keystone Jack
Background and Identification
Ethernet cables are cables which carry data within a network. If your computer has an Ethernet jack (modern slim computers often don’t, but you can buy an adapter) you can connect the device directly to your home or office network using an Ethernet cable. One end of the cable goes into your computer; the other end plugs into a matching socket usually located on the wall. Since a huge number of devices can now connect to a network using fancy Wi-Fi, you might wonder why anyone would use Ethernet cables anymore. There’s a few upsides at the cost of an annoying downside:
- Pro: Ethernet cables are more reliable than Wi-Fi. Ethernet cables just work.
- Pro: Ethernet has lower latency than Wi-Fi. Using Ethernet cables will usually grant you lower ping in online games.
- Con: You can’t move around because your computer is attached to the wall. Drat!
The other limiting factor of Ethernet is that you need to have access to an Ethernet outlet. Most routers have a few Ethernet ports which you can use directly, but you might need a pretty long cable if you want to connect your computer to a router located on the other side of the building. If you have the time and patience, an alternative solution is to install Ethernet cables through your walls. This is the method used in many offices and newer homes which have the installation done during construction. This video on YouTube provides a good overview of the process of installing Ethernet cable in pre-existing walls.
Another important consideration with regard to Ethernet cables is the type of cable you use during installation or to connect your computer directly. You see, the phrase “Ethernet cable” is technically a misnomer. Ethernet itself is a generic method of communication; the data that is transferred via Ethernet can move along a number of different cables such as fiber-optic cables or coaxial cables (the same type used for antennas or radios). The oldest Ethernet setups used coaxial cables, while the newest high-speed applications use fiber-optic cables. In a standard environment, however, Ethernet is transferred over a cable containing pairs of twisted wires.
While this distinction is fairly pedantic, knowing the difference might save you from an attack by the IT gods.
Twisted-pair cables used for Ethernet are usually called Category 3, Category 5, Category 6, etc. with higher category cables made to support faster transfer speeds. The downside, of course, is that they cost more. Grrr! See the specifications section below or this nice ElectronicsNotes article for more information on each category cable. If you’re looking at a cable you already have, you can identify the category by looking for small text printed on the outside of the cable. As shown in this trueCable article, the side of the cable will have information such as the category included in this small text.
- Category 3: 10 Mbit/s
- Category 5: 1000 Mbit/s
- or 1000BASE-T
- Category 5e: 2.5 Gbit/s
- or 2.5GBASE-T
- Category 6: 10 Gbit/s (up to 55 meters)
- or 10GBASE-T
- Category 6a: 10 Gbit/s (up to 100 meters)
- or 10GBASE-T
- Category 8: 40 Gbit/s
- or 40GBASE-T
- Category 3: 16 Mhz
- Category 5: 100 MHz
- Category 5e: 100 Mhz
- Category 6: 250 Mhz
- Category 6a: 500 MHz
- Category 8: 2000 MHz
- Category 3: unshielded
- Category 5: unshielded
- Category 5e: unshielded or shielded
- Category 6: unshielded or shielded
- Category 6a: unshielded or shielded
- Category 8: shielded