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BOOT CAMP 281 (01/07/03)
Wireless Networking, part 1
For once the hype is true! With wireless networking you can
share your broadband Internet connection with any PC in your home or surf the
net from your laptop in the back garden and ‘hotspots’ in airport departure
lounges and outside coffee shops, so what’s the catch?
There isn’t one, wireless networking works, it’s easy to
install and configure and it is getting cheaper all the time. You could, for
example, network two PCs and a laptop for less than a couple of hundred pounds.
Not only will it allow everyone in your home to access the Internet you’ll also
be able to swap files between computers and share resources, like printers and
scanners. Storing your files on separate computers is also a good way of backing
up and protecting valuable or irreplaceable files such as documents, accounts
and digital photographs.
Over the next few weeks we’ll be looking at how to set up
your own home wireless network or ‘WLAN’ (wireless local area network) and share
your internet connection but before we get down to the nitty-gritty we’ll
quickly run through the technicalities and deal with some more of those pesky
acronyms, a few of which are worth remembering when you go shopping for the
necessary hardware.
There are several wireless networking systems on the market
but I strongly advise you to stick with the most popular one, known generically
as 802.11b or ‘Wi-Fi’ which allows data transfer speeds of up to
11megabits/second over distances of up to 100 metres (though in practice
transfer speeds are typically around half as fast and the range inside a
building may only be around 25 metres). It is the closest to an international
standard and because it is so popular the parts are relatively cheap and readily
available moreover it’s the system you’re most likely to encounter when you are
out and about with your wireless-enabled laptop or organiser. In fact there are
several different versions of Wi-Fi and you may come across 802.11a and 802.11g
types, both are faster (up to 54Mb/sec) and the latter is backwards compatible
with 802.11b but for the moment they can be safely ignored them, assuming that
you want to keep things simple.
So how does it all work? There are various different types of
network configuration but the two commonest methods are ‘Ad Hoc’ and
‘Infrastructure’. In an Ad Hoc setup all wireless devices can communicate with
one another, which is fine for file sharing files but it makes it harder for
individual PCs to connect to common resources, like a printer or the Internet.
In an Infrastructure network one PC is designated a ‘Server’ – usually the one
that is connected to the Internet -- and all of the other PCs on the network
become its ‘Clients’. The Server’s is connected to a device called a Router or
Switcher, which acts like a telephone exchange through which all of the PCs in
the network can communicate with one another. This type of network is most
suitable for a small office or the home and although the setup is a little more
involved it is more flexible and lends itself more easily to expansion.
In a conventional wired infrastructure network all of the PCs
are connected by ‘Ethernet’ cables to the Router. A wireless network is no
different except that instead of cables each PC sends communicates with the
router by radio signals using small transceiver (transmitter/receiver) modules
or Wi-Fi ‘adaptors’. These can either be built into the computer or in the form
of an add-on devices that plug into a USB socket, PC Card slot (common on
laptops) or an expansion socket on the PC’s motherboard.
You may be wondering about security, and how easy it would be
for someone to hijack or hack into your network? It is a concern but all Wi-Fi
products have a powerful encryption system built in called WEP or Wired
Equivalent Privacy. However, whilst the highest level provides a sufficient
degree of protection for most non-sensitive applications it’s worth knowing that
it is disabled by default on virtually all Wi-Fi products and it is up to you
switch it on and use it, but more on that in a later episode.
Another reason to enable encryption is a small but growing
underground cult known as ‘Warchalking’. Individuals with Wi-Fi equipped laptops
roam the streets looking for ‘open’ wireless systems, which they attempt to
access. When they find one they leave coded chalk marks on the pavement or wall
outside the premises as a sign for others. Most of the time Warchalkers are
simply looking for free Internet access and tend not to infiltrate networks, but
the potential for hacking is obvious so it’s a good idea to enable the security
features on your system. For an insight into Warchalking have a look at: http://www.warchalking.org/
As the number of WLANs increases so too does the possibility
of interference though here in the UK
and the rest of Europe 13 radio channels have been allocated to 802.11b Wi-Fi
systems and it shouldn’t be a problem for most home users, but if you live in or
close to a commercial district it’s something else to be aware of.
Next week – Wireless networking, part 2
JARGON FILTER
ETHERNET
Industry standard networking system that allows the transfer
of data over cables at speeds up to 100 megabits per second
HOTSPOT
Public Wi-Fi access point, users are normally required to pay
a fee or subscription before they can log on
ROUTER
Device in a network that transfers data between computers
TIP OF THE WEEK
Your network and every PC connected to it will require a
unique name and identity so now might be a good time to think about it; if you
don’t Windows will assign default names and possibly make it easy for snoopers
to infiltrate your system. Give your network a simple but not too obvious name,
based on your name, the street you live in or a family pet for example. In this
example we’ll call our network ‘Fido’. Every PC now needs a name based on the
network name, i.e. Fido1, Fido2, and so on. Finally, give each PC an identity,
so you know what and where it is or who uses it, e.g. ‘officeibm’, ‘kidsdell’, ‘compaqloft’ etc. It’s a good
idea to jot all this down, either on a sheet of paper or create a simple table
in Word with enough rows for each PC (plus a couple of spares), and keep it in a
safe place.
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