All about ethernet
Let’s talk wires.
Normally Wi-Fi gets all the press. Nobody ever mentions the old reliable wired networking anymore, so this month we thought we’d try and rectify that a little and take a look at the backbone of nearly all modern local networks: Ethernet. What is it, how has it changed, and how does it work? Can you make your home Ethernet work better, and do you need to?
A very brief overview of Ethernet
Ethernet is the name of a standardised system for sending data over wired connections. When people talk about “wired” in a local area network context, they pretty much mean Ethernet.
Technically speaking, Ethernet is a layer-2 (data link) protocol that manages how data is sent between devices as well as how contention is managed.
The term layer 2 is somewhat important here. We don’t have the space (nor the desire to send you into a coma) to give a full overview of the OSI model, but layer 2 sits above the physical layer (layer 1) and describes how data is packeted and framed for delivery between devices on the network and how a shared medium is managed.
As such, Ethernet actually binds to different physical mediums. It can work over coaxial cable, twisted pair copper and fibre optic cable. Home users nearly exclusively use twisted pair/RJ45, but optical connections are commonly used in long-range wide area and metropolitan area connections. Coaxial, has largely been assigned to history.
It’s available in a variety of speeds, from 5mbps to 400gbps, though the maximum over twisted pair is 40gbps. There’s a naming nomenclature that describes the speed and gives an indication of the type of physical medium. The most common are 100BASE-T, meaning 100mbps over twisted pair (also known as Fast Ethernet); 1000BASE-T (1000mbps over twisted pair, also known as Gigabit Ethernet); and 10GBASE-T (10gbps over twisted pair).
Advantages over wireless
So is it worth running Ethernet cable around your home, especially now that wireless speeds are so fast? The simple answer is absolutely yes, or at least yes where practicable to fixed devices like smart TVs, consoles and desktop PCs.
The key advantages over wireless can be summarised in four points:
• Lower contention. You’re not competing with your neighbours for space on the airwaves. The wires are all yours.
• Lower latency. Ethernet offers substantially more responsive internet connectivity than wireless, which is better for
gaming and real-time applications.
• Absolute reliability. Ethernet generally doesn’t suffer from sudden dips or stutters; you get rock solid throughput all the time.
• No security requirements.
Because it requires physical access, Ethernet doesn’t have the security overhead needed by Wi-Fi. It’s plug and go, no passwords or SSID required.
Really, the only practical advantage that wireless has is mobility, so where you can wire, you should wire.
Speeds of Ethernet
When it comes to home use, by far the most common type of Ethernet is 1000BASE-T, which is 1gbps over twisted pair cabling. Unlike wireless, you generally get pretty close to the rated speed on Ethernet. Transfers over 1gbps Ethernet, assuming no other devices are competing for the connection, will typically hit in the 600-900mbps range, with lower speeds usually caused by weaker hardware at the end points rather than anything to do with the medium itself.
If you have older devices lying around, some might still use Fast (100mbps) Ethernet. These won’t slow down the network as a whole (Ethernet is cross-gen compatible), but it’s probably a good idea to think about upgrading them since they will struggle with modern broadband and make file copying painful.
Some newer routers and switches, as well as many new network attached storage (NAS) devices also support 10GBASE-T. If you have a NAS device that supports it, we recommend getting a router that supports it as well. The link between the router and NAS is likely to be a high-traffic link, with multiple users competing for access, and having as fast a link as possible will be helpful.
Are there quality differences in cables?
Each speed standard for Ethernet has a minimum cable quality requirement. Twisted pair Ethernet cables are rated for speed, and when you buy them the cables will have a “category” rating, most commonly Cat 5e, Cat 6, Cat 6a. Cat 5e is usually unshielded (UTP), meaning that there’s no electromagnetic shielding around the wires. Cat 6 can either be unshielded or shielded (STP) and Cat 6a is usually shielded.
Technically speaking, for Gigabit Ethernet, you only need Cat 5e but Cat 6 is recommended. For 10gbps you need minimum Cat 6a. The cables can be up to 100M long (technically longer with some Cats, but we wouldn’t go over 100M) and there are limits on bends and folds, so try not to fold or pinch the cables.
If you’re planning on wiring up your house with structured cabling, we recommend going as high as you can afford, but a minimum of Cat 6a to support 10gbps (the shielding is also helpful if it’s running next to power lines). If you wanted to go all out and have the money, you can even go as high as ultra-expensive Cat 8, which is required to support 25gbps and 40gbps Ethernet.
But apart from the category rating, we wouldn’t pay too much attention to other “quality” factors. There are “audiophile” and “videophile” Ethernet cables that get advertised with a massive markup in price, but just as with special HDMI cables, this is mostly a scam, and you won’t get better performance out of them.
Switches and topography
One of the reasons Ethernet ultimately triumphed over other more “elegant” protocols like Token Ring and FDDI is that it is completely flexible when it comes to the arrangement of devices on the network. Just plug anything into any port and it should just work.
That means, for instance, if you have four devices in your loungeroom that you’d like to hook up, you can buy a simple Ethernet switch, typically costing in the $50 range. Connect any LAN port on that switch back to any LAN port on the switch built into your router. Then plug your loungeroom devices into the switch and the switch will relay them back to the router. It’s all very plug and play – as long as there’s a route, Ethernet will find it.
In complex networks you do have to start thinking logically about topography if you want to keep performance levels. In the scenario above, for example, the link between the switch and the router is going to be heavily trafficked, since that one link is going to be supporting four devices. That might affect performance, and you might want to consider higher speed Ethernet for such “backbone” links or about how you arrange your connections and where the heavily trafficked parts of your network are likely to be. But for most home users with gigabit Ethernet it will be good enough to just plug anything into anything, and let the magic of Ethernet sort out the routing.