COMPATIBILITY ISSUES | Home Networking Annoyances: How to Fix the Most Annoying Things about Your Home Network

The only network equipment compatibility issues you're likely to run into are for wireless networks and wireless devices. The first compatibility issue is the operating system. If you're really interested in wireless networking, every computer in your house should be running Windows XP. The earlier versions of Windows just don't offer the support for wireless communications and wireless security that Windows XP offers.

Windows XP also has better (and easier-to-use) features for networking, regardless of the topology you're using to connect your network. Consider upgrading to Windows XP even if wireless networking isn't the motivation.

UPGRADE TO WINDOWS XP

If you're running Windows 98, 98SE, or Me, you can update your computer to Windows XP Professional Edition or Windows XP Home Edition if it meets the hardware requirements. If you're running Windows 2000, you can only update to Windows XP Professional Edition. Here are the minimum hardware requirements for your computer if you want to update to Windows XP:

PC with 300MHz or higher processor clock speed
128MB or more of RAM
1.5GB of available hard-disk space
Super VGA (800 x 600 or higher resolution) video adapter and monitor

Microsoft has a tool called the Upgrade Advisor that checks your system hardware and software to see if you can upgrade your computer to Windows XP. You can download the software, or run it while connected to the web site. The advantage to running the Upgrade Advisor while connected to the Internet is that if your system needs updates that are available on the Windows Update web site, the software finds and installs what you need right away. Go to Microsoft's web site (http://www.microsoft.com/) and search for the Upgrade Advisor.

UPGRADE WINDOWS XP COMPUTERS TO SERVICE PACK 2

Microsoft's release of SP2 for Windows XP introduced a host of new features, many of which are aimed at networking and wireless security. Because you're running a network, and because you might be using wireless components in that network (or might introduce them in the future), considering upgrading your Windows XP computers to SP2 (http://www.microsoft.com/windowsxp/sp2/default.mspx).

Tip: Windows XP SP2 is especially important for security in wireless networks because it natively supports WPA security, discussed later in this section.

WIRELESS ALPHABET SOUP COMPATIBILITY

Most of the wireless equipment you'll find today is 802.11g. If your existing equipment is 802.11b, the 802.11g network devices interoperate with wireless-b devices (this is called backward compatibility, or downward compatibility). Some 802.11g equipment is marked "wireless g-b" to indicate the compatibility, but even if you don't see that designation on the box or on the web site specifications, you can buy 802.11g devices with full confidence that they will work with your existing 802.11b equipment.

Tip: Depending on when you bought this book, you might have even more choices for wireless technology. As of this writing, 802.11i technology is being tested and should be approved and standardized in the near future. This new version of Wi-Fi technology brings wireless networking more speed and distance, as well as greatly enhanced security features.

WIRELESS SECURITY COMPATIBILITY

When you buy new wireless adapters, routers, or access points to expand your network, you're going to find devices that support Wi-Fi Protected Access (WPA) security technologies. WPA is a higher-level security standard than Wired Equivalent Privacy (WEP), the previous security standard. WPA substantially raises the level of data protection and access control for wireless networks. WPA provides several benefits to enhance security, not the least of which is its support of user permissions and passwords for allowing network access. The data encryption level provided by WPA is more robust than that of WEP.

Tip: WPA is forward compatible with the upcoming 802.11i standard, so investing in equipment that supports WPA is worthwhile.

To use WPA security you must have an access point or a wireless router. (All wireless routers have built-in access points.) All of the wireless devices on your network must support WPA. Your existing wireless devices are probably not WPA-enabled, but you don't have to toss them out and buy new ones. Instead, you can download a firmware upgrade from the manufacturer's web site. After you install your WPA access point or router, you can upgrade the network adapters gradually. WPA and WEP can coexist on the same network (the WEP devices just ignore the features available in WPA).

Don't even try to use WPA on any version of Windows other than Windows XP. Although you can probably configure a WPA network on Windows XP without updating to SP2, it isn't easy. The built-in support for WPA in SP2 makes upgrading imperative.

WEP AND WPA ENCRYPTION DIFFERENCES

One of the big differences between WEP and WPA is the method by which the systems encrypt data. WEP uses 64-bit or 128-bit encryption keys, but WPA offers 256-bit encryption keys, which are exponentially harder to decode.

WEP encryption keys are static, but WPA keys are dynamic, and automatically change as often as you specify when you configure the wireless device (most manufacturers default to 50 or 60 minutes, which is quite acceptable). Hackers who try to learn your encryption key by eavesdropping on your network would have a hard time breaking in. Even with powerful encryption-breaking software, by the time they gain the information they need to decode the current key, your network has switched to a new key.