Ethernet Standards – N10-008 CompTIA Network+ : 1.3

There are many ways to implement an Ethernet network. In this video, you’ll learn about the different speeds and connectivity types for popular Ethernet standards.

By far, Ethernet has to be the most popular networking technology in the world. It is used in practically every organization to connect devices and be able to connect us together using the internet. To be able to make all of these Ethernet connections work, we use many different types of cabling, different types of equipment, and different types of connector. These days, our modern Ethernet networks will use fiber and twisted pair copper, but you may run into other types of connectors as well.

One common technology used across many of these different Ethernet standards is baseband technology. This means there is a single frequency that’s using the entire medium. That means across this wired connection or fiber connection, we are using a single type of frequency to be able to transmit these Ethernet signals. This is different than a broadband connection. With broadband connectivity, you have a single wire, but you’re sending many different frequencies across that wire, effectively sharing the medium for all of those different communications channels.

If you have some older 10-megabit Ethernet cable running over twisted pair wire, then you’re probably using the 10BASE-T standard. The 10 would be for 10-megabit, the BASE would be for the baseband technology that’s used on that wire, and generally, you’d see a T or a TX at the end to specify that that is twisted pair. 10BASE-T uses two pairs of wire within that cable, which is different than the four pair that we commonly see with gigabit Ethernet technology, and this only requires Category 3 cable. This goes back a number of years, and Category 3 was perfectly acceptable to run 10-megabit Ethernet. The maximum distance supported with 10BASE-T Ethernet is a 100-meter distance.

We increased the speed of our Ethernet networks 10 times and created 100-megabit Ethernet. This is 100BASE-TX. Sometimes you’ll see this referred to as fast Ethernet, although these days, 100-megabit Ethernet is not the fastest that you will commonly find. This also used two pairs of wires within that cable, and it uses a minimum of Category 5 cable extended over a 100-meter maximum distance.

We improved the Ethernet technologies and introduced 1000BASE-T, or what is known as gigabit Ethernet over Category 5 cabling. This uses all four pairs of wires within that single cable, and although Category 5 cabling is now deprecated, we tend to see Category 5e used in its place. This move to use all four pairs of wires within the cable is very different than the two pair that was used for 10BASE-T or 100BASE-TX.

That’s why you’ll sometimes see some patch cables that only have two pairs of wires run inside of them because they were made for the older standards. And if you try to use those with 1000BASE-T, you won’t be able to get gigabit speeds. As with 10BASE-T and 100BASE-TX, the maximum allowed distance in the 1000BASE-T standard is 100 meters.

Increasing these speeds again by a factor of 10, we can support 10GBASE-T standard, or 10 gig Ethernet over copper with this four pair balanced twisted pair cabling. This uses a higher frequency to communicate across this connection. Normally, 125 megahertz was the frequency of signal that you would see on a gigabit Ethernet cable. For 10GBASE-T, we’re using frequencies of 500 megahertz. That increased frequency rate translates into more data being sent across this connection.

10GBASE-T requires a minimum of Category 6 cabling, and if you’re using unshielded cable, the maximum supported distance for the 10GBASE-T standard is 55 meters. If you’re using shielded cables, you can go up to 100 meters in length. There’s also Category 6A cabling, that A stands for Augmented, and Category 6A can support 10GBASE-T over shielded or unshielded cabling up to 100 meters.

One of our newer Ethernet standards is 40GBASE-T, and as the name implies there, this is 40 gigabit per second Ethernet over twisted pair cabling using all four of the pairs within that cable. This requires a minimum of Category 8 cable, and it only allows communication up to 30 meters based on the 40GBASE-T standard.

When you add fiber as a method of communicating between devices, you can extend the speeds and distances of this Ethernet signal. 100-megabit Ethernet over fiber can be used with the 100BASE-FX standard. This is a pair of multi-mode fiber. In fact, it uses some of the same fiber technologies that we used back in the FDDI networking days, for those of you that remember back to those time frames. Just as there are Ethernet standards for copper cabling, there are also Ethernet standards for fiber.

If you wanted to send 100-megabit Ethernet over fiber, you could use the 100BASE-FX standard. This uses a pair of multi-mode fiber. In fact, it’s the same fiber type that we were using for the older FDDI technologies, so this standard would allow us to move between FDDI to the new 100BASE-FX by using the same fiber that we have already run.

This commonly uses lasers to be able to send that light and can communicate over half-duplex to a maximum distance of 400 meters, and using full-duplex, we can go to 2 kilometers. There’s a less expensive version of this 100-megabit Ethernet over fiber standard with the 100BASE-SX. This allows us to communicate 100-megabit Ethernet using LED optics, which tend to be less expensive. But this also limits our distance to be able to send this signal to 300 meters.

If you’re running gigabit Ethernet over fiber connections, you might be using 1000BASE-SX. This is gigabit Ethernet using a short wavelength laser. And as the name implies, this is a shorter distance than a longer wavelength laser that we’ll look at in a moment. This allows us distances over multi-mode fiber to extend 220 meters to 550 meters depending on the type of fiber that you’re using.

If you wanted to have a longer distance that’s supported, you might want to use the 1000BASE-LX standard. This is also gigabit Ethernet, but it’s using long wavelength laser to send the light. On multi-mode fiber, you can extend this to 550 meters, and for single-mode fiber, you can go to a distance of 5 kilometers.

10-gigabit Ethernet standards are also available for fiber connections. The 10GBASE-SR, or Short Range, uses multi-mode fiber to be able to extend 26 to 400 meters depending on the type of fiber that you’re using. If you want to go very long distances using 10-gigabit Ethernet, you might want to use the 10GBASE-LR standard, the LR is Long Range, and using single-mode fiber, we can extend that to 10 kilometers as its maximum distance.

You’ve seen some examples of using Ethernet signals over fiber, but it would be useful if we could send multiple types of signals over the same strand of fiber. We’re able to do that using a technology called WDM, or Wavelength-Division Multiplexing, where we can have bidirectional communication over a single stranded fiber for multiple types of signals. This uses different wavelengths for each carrier that we happen to be sending across that fiber. You can think of this as sending different colors of a signal over the same strand of fiber.

One common type of WDM is Coarse Wavelength-Division Multiplexing, or CWDM. This is the 10GBASE-LX4 standard using four separate 3.125-gigabit per second carriers at four different wavelengths. If you want to fit more signal over that fiber, you might want to use DWDM, that’s Dense Wavelength-Division Multiplexing, and it is dense. This is multiple carriers on a single fiber. You can have 160 signals and increase the total throughput to approximately 1.6 terabits per second.

Multiplexing is in the name. That’s what’s really happening when we send this traffic through this fiber. Here are three different sources of signal going into the multiplexer being then sent across a single fiber, and on the other side, we’re demultiplexing those signals onto their separate streams.