Ethernet Standards – CompTIA Network+ N10-007 – 2.1

| April 3, 2018


The IEEE maintains Ethernet standards that apply to many different speeds and media. In this video, you’ll learn about 100BASE-TX, 1000BASE-T, 1000BASE-SX, 1000BASE-LX, and 10GBASE-T standards.

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By far, Ethernet is the most popular network topology in the world. Somebody has a network, and they have some flavor of Ethernet that they’re using in their environment. And there are many different types of Ethernet running different speeds, different types of cabling, different types of connector and different types of network switches.

In the past, we may have run ethernet over coaxial cables, but these days most modern Ethernet networks will be using twisted pair cabling or fiber optic. If you’re running 100 megabit Ethernet over twisted pair cables, then you are using 100BASE-TX. You’ll sometimes hear this referred to as fast Ethernet, which is what we called 100 megabit when it was released after using 10 megabit Ethernet for so long.

100BASE-TX uses category 5 or better twisted pair copper cabling, and it uses two of the pair that are inside of that cable. It does not use all four pair to communicate. And the maximum length of a cable run for the 100BASE-TX standard is 100 meters in length.

Moving up from 100 megabit Ethernet, we move into gigabit Ethernet or 1000 megabit. The standard for gigabit Ethernet that most people are using is 1000BASE-T. 1000BASE-T gigabit Ethernet runs over category 5 twisted pair cable or better. If you look at the EIA TIA standard, you’ll see that category three, four, and five cable is deprecated. So usually the minimum cable that you’ll find available to run for 1000BASE-T is category 5e.

And instead of using the two pairs that we used for 100 megabit Ethernet, our 1000BASE-T gig Ethernet requires that we use all four pairs inside of that twisted pair of cabling. If you need to run Ethernet pass that 100 meter limitation for copper cabling, then you’ll probably want to connect equipment using fiber. And of course, there are gigabit Ethernet standards for fiber optics.

One of these standards is 1000BASE-SX. This is gigabit Ethernet running at 1000 megabits per second using what’s called NIR or near infrared light bandwidth. The standard commonly uses multi-mode fiber as it’s physical medium, so we can extend this Ethernet connection generally 220 to about 500 meters in length depending on the type of fiber that we’re using.

For much longer ethernet connections, you may want to use 1000BASE-LX, which is gig Ethernet using a long wave length laser. You could run 1000BASE-LX over multi-mode fiber, and you get about 550 meters in length. But if you really need to extend the length up to five kilometers, you can use 1000BASE-LX over single mode fiber.

If you’re really looking to push the throughput of copper cabling, you can run 10 gig Ethernet over copper or the 10GBASE-T standard. This uses frequencies up to 500 megahertz inside of this cable, which is well above what we use for our gig Ethernet connections of 125 megahertz. Because of that, we will need cable that’s specifically designed to support these higher frequencies.

So for 10GBASE-T, you’ll be able to get 55 meters in length. If you’re using cat 6 cable, you can upgrade to category 6, which stands for augmented, if you need to go to 100 meters. And if you need additional shielding from interference, you can choose a category 7 cable that is shielding not only the entire cable itself, but each individual pairs of wire.

Category: CompTIA Network+ N10-007

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