Choosing an ADSL router

Broadband Equipment

What is an ADSL router?

A router is a free-standing link to the your ISP. It knows your username and password, and maintains the connection so long as it's powered on. As it's a separate box normally left on all the time, that means that your connection is always ready to go — no need to log on each time, even if you turn off the PC when you're not using it.

The router is one device on a LAN (Local Area Network), so to set it up you need to create a LAN. This involves getting a network hub (often called a network switch) and plugging everything into it. (It uses a protocol called Ethernet, so you may see the hub called an Ethernet hub or an Ethernet switch.) Many routers have a hub or switch built in — a router plus four-port hub is common, so you could plug up to four things into it, and they'd all be able to connect to each other, and they'd all share the connection your ISP.

Even a router that doesn't have a hub built in will still have one Ethernet socket, so you plug either a single PC (with a NIC) or a separate hub into that.

To plug a PC into the hub or switch, the PC will need an Ethernet card (often called a Network Interface Card, or NIC). Many PCs already have a NIC fitted, or they can be bought separately (in PCI or PCMCIA shape) and fitted to each PC.

Finally, a router will do Network Address Translation, NAT. This is a useful security benefit — it means that all your PCs have private addresses that are never exposed to the Internet, and the only device visible from the Internet is the router itself. This makes your PCs much less susceptible to Internet-based attacks, but you still need to run anti-virus software to protect against things you collect yourself, like e-mail.

If you use a modem your PC is directly visible from the Internet and all sorts of things will be probing it for weaknesses, so you absolutely must run a firewall on the PC. With a router this is much less necessary, although it might still be a good idea because a personal firewall will protect you against attacks from other PCs on your LAN and will also allow you to check what is speaking /outwards/ from your PC to the Internet.

Should I get an ADSL modem or an ADSL router?

ISPs often provide an ADSL modem as part of the package; generally it's not a good idea to take one of these, they tend to be expensive and of poor quality. If you're going to get an ADSL modem at all, buy it from an equipment supplier, not an ISP — it'll probably be about £30 cheaper.

But I'd recommend that you consider getting a router, not a modem. A router is a little harder to set up (but I can do that for you) and is generally much nicer to use. Here's a detailed comparison:

ADSL Modem	ADSL Router
Typical price about £30	Typical price about £60
Insecure	Secure
Turn off with PC	On all time
Single PC	Multiple PCs, games consoles, etc
No wireless (must have a wire to the PC)	Can have wireless (so PCs don't need a physical connection to it)
Log in and out	Logged in all the time
Plugs in to PC's USB port	Usually needs LAN card in PC (not always, though)
Will use up some processing power on the PC	Entirely self-contained — does its own processing, so no load on the PC.
Recommended by ISP	Better solution
Typical product here.	Typical products here and here.

Which is the best router?

Top of the range for home users are the Vigor range from Draytek and the Prestige range from Zyxel, but there are plenty of cheaper models from Netgear, D-link, Linksys, Belkin, Solwise, Plexus and such like. These generally work well enough, but are maybe of slightly poorer build quality and/or reliability.

Also have a look at www.solwise.co.uk and www.seg.co.uk — both good sites.

I have every reason to believe the Zyxel are excellent routers, and so are many others. People tend to recommend what they know (so long as it's good, of course) and plenty of people know and like the Zyxel range.

It's a bit like asking what is a good word processor, and why. In the end it's hard for anyone to say why they prefer Word or WordPerfect, or vice versa — they are both good, it just depends which one you've got used to,

With routers, people who install a lot of them like them to work reliably, and for the interface to be consistent across the range. If you don't know one end of a router interface from another, you'll possibly not care too much which one you choose, but make sure that most or all of the functions are accessible via the web interface, and that the menus are sensibly laid out. I've always liked the Vigors, but that's because I know them.

Is a router easy to set up?

With a good modern hub+router, basic set up is little more than:

1. find out what its default LAN address is (so that you can point your browser at it),

2. find out what its default admin username and password is, so you can log in to its web interface, and

3. stick in your ADSL logon and password.

All the defaults should already be set to sensible values.

If not, or if you want to tinker, you'll need a basic grasp of networking concepts — you'll need to know what an IP address, subnet address, gateway, and MAC address are, and what DNS, DHCP, CHAP, PAP, and so on do.

You might also need specific "secret knowledge" like knowing that BT ADSL requires a VPI setting of 0 and a VCI setting of 38.

As an example, I've recently set up two different models of cheap and cheerful routers. Out of the box one was configured as 192.168.1.1 and the other was 192.168.0.1, one had admin username DSL and one had admin username ADMIN, and having put ADSL username and password into both one just started working and the other one didn't. Turned out that the one that didn't work was using CHAP authentication by default, and I knew it should be PAP, so 30 seconds later it was working too.

For one of them I wanted to get its DHCP server to always dish out the same (fixed) IP address to a particular MAC address (in a server on the network) — couldn't do that through the Web interface and had to telnet in and fiddle with the command line. Easy once you know.

If your hub+router does wireless as well, do the setup over a cable. When it's all working OK and you can get on the Internet, then (and only then) see if you can get the wireless bits to work.

A router doesn't plug directly into your PC — you need to set up a LAN and plug the PC into that. That means that your PC needs a working LAN card (many PCs have one fitted by the manufacturer; if not one can usually be fitted easily) and to have networking enabled and configured.

Hope that helps to give a flavour of what you're in for. It could be completely painless, or it could need a bit of reading up on all the various terms.

Or get me to do it for you.