Planning a Wireless LAN

You might have no problems whatsoever setup, configuring, and maintaining your wireless network. Then again, George Steinbrenner might start voluntarily and cheerfully restricting the payroll of the New York Yankees so they compete more evenly with the Kansas City Royals.

The fact is, wireless connections and the networks that depend on those connections sometimes go awry. You should begin your WLAN adventures by planning for problems.

Connection Planning

The greatest disappointment in setting up a wireless network occurs when it fails to work for the first time. Typically, wireless networks malfunction periodically for any number of reasons.

But it’s dispiriting to use your wireless-enabled laptop in one location one day, with network connections strong and reliable, only to use it in a slightly different location the next day with no connection at all, or a sporadic connection at best. You can’t always stop this from happening, but you can make plans to better the situation.

The following list shows a variety of options for planning for connection difficulties.

  • Misdirected Antenna: Experiment with the antenna on your wireless access point (AP).

One of the common mistakes people make with setup a WLAN is thinking that the antenna doesn’t do much. It does, sometimes in a major way. Even a small adjustment can make the difference between a poor connection and a fair to excellent one.

  • Not Enough Breathing Space: Give your access point some air.

Instead of having it surrounded by books, papers, and other equipment, get it out in the open where it has a chance to broadcast its radio signals. This is a transmitter, remember, and it needs room to transmit.

  • Frequency Interference: Your WLAN isn’t the only thing using your WLAN’s frequency.

In the same way that radio stations can interfere with each other on your car stereo, two wireless devices can interfere with each other in your house or office.

Culprits typically include cordless phones, but microwave ovens, video beaming equipment, and baby monitors can also cut into your reception. Experiment with all your equipment to choose separate channels for each until you can have everything on at the same time with flawless reception.

  • Difficult Architecture: No, not network architecture, but building architecture.

Wireless signals often have trouble getting through walls, floors, and ceilings. They have even more trouble getting through multiple barriers.

Sometimes you can solve the problem by placing the access point at a middle point of the floor or building and running an Ethernet cable from the router to the AP. Other times you have no choice but to add another AP, daisychaining them together to cover a larger area.

  • Malfunctioning Equipment: Networking equipment can and does malfunction.

Sometimes it’s the wireless component of your router/access point. Sometimes it’s the router port itself. Sometimes it’s the network adapter card in your notebook. And sometimes it’s a more complex network problem, such as failure to bridge the wireless network with the wired network.

The best solution is always to have more than one of everything available for use (even if only a few lower-cost spare devices sitting in a cupboard available for emergencies), and if your business depends on your WLAN, you certainly want to establish that level of redundancy.

For home users, the only solution is to track which part is going wrong and make adjustments accordingly. Planning for such problems often means nothing more than installing each component separately, and ensuring that it functions properly before installing the next component.

  • Altered Configurations: Anyone with access to your WLAN’s configuration screens, even legitimate access, can cause problems across the network simply by changing the configuration.

Before attempting to fix anything, in fact, it’s a good idea to open the configuration utility (which is often browser-based) and determine that nothing has been altered.

Changed network names, channel numbers, even network names—all of these can render your wireless device unusable over the network. If you see changes, either change them back or, at the very least, write down the changes and then make precisely the same alterations to your device’s configuration.

Security Planning

Ever heard of a war driver? War drivers are people who drive around cities and towns, their notebook (or PDA) and Wi-Fi access card in tow, looking for wireless networks they can access.

As they pass businesses and houses, they click on a link in their browsers, or try to log on to a Windows network from Network Connections or Network Neighborhood, and see if the connection occurs.

When it does, they stop and use that network as long as they feel like. If that network is yours, and you haven’t taken precautions to secure your PC, you’ve just opened your computer to a total stranger.

This activity, of course, is unique to wireless. The only way to tap into a wired network is to plug a device physically into the network itself, usually into a router or switch.

If you can’t get to the physical linkage, you can’t get onto the network. Tapping into WLANs is completely different because the only thing the hacker needs is a way to receive your radio signals. And many, many people do.

In fact, security lies at the core of most discussions about wireless networks today. Partly by their technological nature, and partly because of the way the components ship, WLANs seem to defy whatever security measures their owners put in place.

It doesn’t have to be that way, as you’ll see elsewhere, but currently it’s a serious issue for everyone from IT professionals to home users. Put those radio waves out there, and somebody will want to steal them.

The following list outlines several ways to plan against security problems.

  • SSID Alert: The SSID of a WLAN acts as the identifier for that WLAN.

By default, most access points are set up to broadcast the SSID, so that anybody with a compatible network adapter can see the network and connect to it automatically. The easiest and perhaps most effective way to stop casual intruders is to configure your AP to stop broadcasting the SSID.

  • Password Protection: Wireless LANs are no different from wired LANs in at least one respect: if you don’t password-protect important data, you’re simply asking to have it stolen.

Set up password protection for folders, disk drives, and any other resource on your network’s PCs, and keep the passwords private.

  • WEP Security: One of the two primary encryption technologies for wireless networking, WEP offers decent security and is readily available.

Setting it up can be trying, especially for network cards that seem to insist on incompatibility, and there’s no question that it can slow down your wireless transfers. But it’s there, and it should be used.

  • WPA Security: Still in its early days, WPA promises much stronger security than WEP.

But incompatibilities with older wireless adapters make it a tough choice to make. You can take advantage of those incompatibilities, though, ensuring that most casual users won’t be able to connect.

  • Turn It Off: If you don’t need 24/7 wireless connectivity, don’t offer it to anyone else either.

Unplug your access point when you have no use for it, and suddenly all other WLAN security issues disappear. Works for homes and small offices alike.

  • VPNs: Virtual Private Networks, even when run over WLANs, can provide much more secure access than WLANs on their own. They’re difficult to set up and administer, but if you’re running a business LAN, you owe it to yourself to give it a try.