Creating a Wi-Fi Network

Understanding the Different Pieces of Hardware

So you want to set up a new wireless network in your home or office. Or, you want to extend an existing wire line network to provide wireless capabilities. In either case, relax! These are pretty easy things to do using Wi-Fi technology. You'll have your wireless network up and running in no time—and be using your computer in your living room, in your garden or on your deck, and from all kinds of unlikely places.

Wireless Networking Kits

A number of companies produce wireless networking kits. These kits are essentially a bundle containing an access point, two wireless PC Cards or wireless USB connectors, software drivers, and instructions.

For example, for around $50 from a discount retailer, you can buy the D-Link DWL-920 kit, which includes an 802.11b access point and two USB 802.11b connectors.

Microsoft's Wireless Desktop Kit MN-610 sells for about $130, and contains "everything you need to set up a wireless 802.11b network" for two desktop computers. Essentially, the contents are the same as the D-Link kit: an access point and two USB wireless connectors. (Yes, the Microsoft USB adapters have a larger form-factor than the D-Link units, and may have a greater range.)

There's nothing particularly wrong with these networking kits, but they don't get you very far. Although the Microsoft kit is a little on the expensive side for what it is, the D-Link bundle might actually save you a little money over buying the pieces separately.

Don't get me wrong—I'm all for anything that will make life simpler for you. But in this case, wireless networking kits don't bring much to the party. You can start with one of them, and expand your network later if you want. Still, it is no more complicated to buy an access point and create your own "kit."

Choosing a Wi-Fi Access Point

A decent 802.11b Wi-Fi access point can be had for between $50 and $100 (in fact, probably for even less than $50). By contrast, an elegant 802.11g unit, the Apple Extreme Base Station, costs about $250 (a little less if you take the model without the external antenna port). Although industrial-strength commercial units can cost a good bit more, the point is that these are not hugely expensive pieces of equipment.

You'll pay more for 802.11g equipment than for 802.11b equipment because 802.11g is newer and faster. This is a choice with obvious trade-offs that you'll have to make.

Likewise, the Apple Extreme Base Station costs a little more than equipment manufactured by a vendor that is not Apple—but then again it is a wonderfully designed piece of equipment with extended range, an elegant form factor, and great ease of use.

Preliminaries

It's good news that usually a standard installation of a Wi-Fi access point is not much harder than plugging it in and turning it on. Typically, you'll be ready to use your wireless network (and shared Internet connection) within minutes.

But, much as I love Wi-Fi technology, I have to be honest. There can be a dark side to setting up a Wi-Fi access point. It's as if you were walking along a mountain path with steep drops on either side. As long as you can keep to the path everything is fine, but if you slip off either side, you can run into trouble.

Trouble tends to come in two forms:2

• If your network is at all complicated, configuring your access point may require a little moxie.

• Access points are tricky pieces of equipment, and a small percentage of them simply ship from the factory with defects.

Plugging in the Hardware

Now that you've collected your current settings, you are ready to rock and roll, er, plug and unplug things.

The first thing to do is to power down the computers on your network, any hubs, switches, or routers, and your cable or DSL modem. You may have to unplug the modem to turn it off because many of these devices don't come with power switches.

Ad-Hoc Networking Ad-hoc networking means that each computer talks to each other directly without the "supervision" of a device such as a router. This arrangement is sometimes called peer-to-peer networking.

Setting Up a Hotspot with a DMZ

Suppose you have a small office with a network, and want to set up a public Wi-Fi hotspot. The single most important requirement is that people who use the Wi-Fi hotspot should not be able to access the office network.

There are many ways to set up a network to do this, depending on the functionality that is required. Also, if you are setting up a commercial hotspot, you should get the advice of the Wi-Fi network provider you will be working with in planning the hotspot (unless you expect to be doing service provisioning yourself). You should also know that there are a number of turn-key "put up a hotspot" kits available, which you can buy and not have to think about further.

In any case, the key concept to protect the private network is the DMZ.DMZ is a term borrowed from the military that is short for demilitarized zone. In networking terms, it means a computer or subnetwork that sits between an internal network that needs to remain secure and an area that allows external access, for example a Web server or a Wi-Fi hotspot.