If your broadband connection only came with a single-output modem, or even a USB modem, then you’re probably wondering how you can extend it, maybe to connect to a laptop, a smartphone or a games console.
There are a few ways to share your broadband with other devices, starting with the Ethernet cable coming out of your modem. If you’ve got a basic USB modem then you’ll need to upgrade it to something with an Ethernet cable coming out, unless you’re happy for everyone to connect through your PC.
Routing over Ethernet cables
If you’ve only got a single Ethernet cable coming out of your broadband modem, then the first thing you’ll need is a Router. This will have at least four more Ethernet ports, and assigns the IP addresses to equipment on your home network so that they can talk to each other, usually using a system called DHCP (dynamic host control protocol) which does it automatically.
Most Ethernet routers run at up to 100Mbps, which is more than enough unless you have a 100Mbps fibre-optic or cable internet connection, or you’re going to have a lot of data going to and fro to something like a networked hard disc for music and video files. In that case, you should get a router that supports Gigabit Ethernet (1,000Mbps). Most new PCs and Macs are also equipped with Gigabit Ethernet ports - look out for “10/1000” or “1000BASE-T”.
Everything connected to these cables is part of your Local Area Network, or LAN.
Ethernet cables are also known as CAT5, CAT5e and CAT6, and are usually terminated in a rectangular RJ45 connector. CAT 6 is a higher-performance cable, but there’s little practical difference between these and you shouldn’t generally run cables longer than 100m. These Ethernet cables are also unshielded, so they will pick up radio interference from fluorescent lights and home entertainment devices, which will reduce the performance of your home network. You can buy shielded Ethernet cable (FTP or higher-quality STP) for use in ‘noisy’ areas such as around home entertainment equipment.
If you need more Ethernet ports without buying a new router, then an Ethernet switch can give you more connections. There’s no setup required and your router will see the switch as though it just has more Ethernet ports.
Ethernet is fine for desktop computers and games consoles, but you’ll want a more mobile connection for a laptop, and there’s usually nowhere to connect an Ethernet cable on a smartphone or tablet PC.
Wireless networking uses the same Internet Protocols as wired networks, but using radio instead of Ethernet cables. Most broadband services come with a wireless router that does both, and if your modem or router doesn’t have wireless, the best way to add it is to buy a new router (either from a retailer or your broadband provider). This is sometimes known as a WLAN or Wireless Area Network.
There are two main wireless networking standards in use today: 802.11b/g (also known as WiFi B/G), and 802.11n (WiFi N). Almost all kit supports WiFi b/g, and newer equipment will have WiFi n as well. Both have a range of about 100m outdoors, or 30m indoors depending on the building materials (steel-frame buildings, metal window shutters and so-on can make a big difference).
WiFi B/G can deliver a top speed of 54Mbps in good conditions, but this is over all of the devices you’ve got connected. It’s also in a very busy part of the airwaves where you’ll often be sharing with other WiFi users and with interference from wireless baby monitors, Bluetooth headsets, and leaky microwave ovens to name a few.
WiFi N can give you up to 300Mbps to share across your devices, it shares better with other users and it can use a much less busy slice of radio frequencies. On the other hand, it’s got slightly less range.
In most cases, WiFi is easy to set up because there’s an access code printed on your router (or on some of the paperwork it arrived with) and your PC or smartphone will ask for this the first time you try to connect.
In large buildings, you can combine WiFi with Ethernet using a WiFi extender or Access Point.
Wireless networks should always be secured, if only to stop dishonest neighbours getting free internet access via your connection. Fortunately, most wireless routers come with security switched on as standard.
There are three common wireless security standards: WEP, WPA and WPA2. WEP is very weak protection, while WPA is an upgrade that shares some of its flaws, so neither should be used if possible. WPA2 is the recommended standard for wireless security on home networks.
You’ll probably also come across WPA-PSK (or WPA2-PSK) and WiFi Protected Setup (or WPS).
WPA2 is designed for home and small office networks and is reasonably secure, provided you don’t use a weak password like a common name or dictionary word - mix upper-case and lower-case letters with numbers, or use a random password generator. The longer your password (from eight to 63 characters), the stronger it will be. A 10-digit random code is practical and strong enough for most, or a 20-character memorable phrase, especially if it contains numbers and mixed-case letters.
WPS is designed to make wireless security easier and you can find it on most recent WiFi equipment, with a simple PIN printed on most WPS routers that’s easy to enter into other devices. Unfortunately WPS has a major security flaw that makes it very vulnerable to attack. You’re now recommended to contact the supplier of any equipment with WPS and ask them how to turn it off permanently, if possible.
Powerline - no new wires
Powerline uses the one set of cables you can guarantee to find running into every room of any building - mains power.
A powerline adapter plus into your mains socket and piggy-backs the data from an Ethernet cable over your mains wiring to other adapters around the house, where it can be accessed via an Ethernet connection or through a built-in WiFi extender. If you don’t want to lose the use of a mains socket, then powerline adapters are available with a ‘pass-though’ electrical socket that you can use in the normal.
The dominant standard is HomePlug AV, which gives practical speeds of around 80Mbps, but the more recent HomePlug AV2 can boost this to about 350Mbps, and you can have up to 16 HomePlug devices connected together.
As usual, these speeds are shared across all the devices you’ve got connected on your powerline network, and if you’re connected to a 100Mbps Ethernet router then your traffic won’t go any faster than that. It’s possible to give certain types of traffic a higher priority, such as video or games, and it’s a useful system for connecting digital TV devices to your router.
HomePlug AV encrypts all signals so they can’t be intercepted and no-one can hijack your broadband by plugging an adapter into the mains. Powerline network signals are usually blocked by your home’s connection to the mains power grid, so your neighbours can’t join your network.
MoCA - turning TV coax into home networks
Lots of homes have coaxial TV cable connecting different rooms, and it’s a cheap variety of high bandwidth cable, so it’s not surprising that you can use it to stretch your home network.
Multimedia over Coax (MoCA for short) is in its early days, but it’s built into a lot of new digital TV kit, ready to be used as connected TV creeps into our homes over the next few years.