Wireless-G: Faster, Cheaper, More Secure

Two years ago, I wrote extensively in Windows & .NET Magazine UPDATE about 802.11b (later marketed as Wi-Fi), the hot wireless technology at the time. Today, 802.11b-based wireless networking products are hugely popular, both in commercial and home settings, and 802.11b-based wireless networking adapters are standard components in notebook computers, PCs, and other network-capable devices. The problems with 802.11b, however, are legion, with performance and security topping the list. This week, I look at the technology that will likely replace 802.11b in the coming months. Later this year, I'll look at some specific products.

Because of the widespread popularity of 802.11b, its immediate successor, imaginatively titled 802.11g, is also marketed under the Wi-Fi umbrella. The 802.11g standard, or Wireless-G as it's sometimes called, runs significantly faster than 802.11b. Whereas 802.11b topped out at 11Mbps, 802.11g speeds can reach 54Mbps. However, these speeds are theoretical. Most 802.11b networks have trouble achieving more than 5Mbps of bandwidth; Wireless-G, in my experience, averages around 22Mbps. However you measure it, Wireless-G is about five times faster than 802.11b. Another competing standard, called 802.11a, also offers speeds up to 54Mbps, but because it's incompatible with 802.11b, you can't access an 802.11a network with an 802.11b card. Wireless-G, meanwhile, is backward-compatible with 802.11b, an important consideration for businesses that have already rolled out wireless technology.

The performance difference between Wireless-G and 802.11b is dramatic. Although 802.11b is fine for email, Web browsing, network printing, and, on an underused network, light file sharing, it's too slow for heavy-duty file sharing, video streaming, or other high-bandwidth tasks. Further complicating matters is the fact that all Wi-Fi networks share bandwidth. Unlike a dedicated wired Ethernet network, in which a router provides the full bandwidth of the underlying network to each attached device, a wireless network shares the total available bandwidth. Thus, more users mean slower speeds. Setting up wireless networks can quickly become complicated because you need to factor in the number of wireless Access Points (APs), based on users, as well as their placement, based on the layout of your office and any obstructions that might hinder performance.

Security is, perhaps, an even bigger concern. Today, most wireless networks are unsecured, which could lead to data theft. The biggest reason for this problem is that although 802.11b devices ship with a security technology called Wired Equivalent Privacy (WEP), this technology generally isn't turned on by default and is easy to circumvent even when it's enabled. For these reasons, enterprises often enable complex and expensive wireless network security infrastructures that bypass the problems with WEP. But today, numerous large and small businesses, not to mention millions of homes, remain unprotected against wireless intruders.

To protect against this problem, Wireless-G ships with a new wireless security technology called Wi-Fi Protected Access (WPA), which some hardware makers are back-porting to their 802.11b products as well. WPA, currently moving through the standardization process, overcomes WEP's limitations and provides what I think is the first generally viable security solution for wireless networks. Here's how it works. WPA automatically changes its rigorously created encryption keys, on the fly, at short intervals. This functionality contrasts sharply with WEP, which generates encryption keys once, allowing network sniffers to examine the wireless traffic and, using widely available tools, break the encryption and break into the network. Also, WPA uses an 8- to 63-character passphrase (what we might call a "password," although it can also include spaces and special characters) to secure the wireless network; this passphrase must be entered in both the wireless AP and in the configuration for any connecting NIC. In contrast, WEP requires inane lengthy keys (26 characters in 128-bit mode) that must be specially constructed.

Although virtually any modern Windows version will work with Wireless-G equipment thanks to vendor-provided drivers, users running Windows XP Service Pack 1 (SP1) will see significant ease-of-use improvements by downloading the WPA Wireless Security Update from Microsoft ( http://support.microsoft.com/?kbid=815485 ). This update lets XP's auto-configuration features work with WPA-equipped wireless networks. The first time you hit a WPA network, you simply supply the required pass phrase and you're good to go. From then on, you'll automatically connect to that network whenever you're in range. You might recall that Microsoft enabled this feature for unprotected 802.11b networks in the initial XP release but removed it in SP1 for security reasons. With WPA, wireless convenience again returns to XP.

Naturally, you'll still want to employ basic security skills for any wireless network, even if you're using WPA. For example, you shouldn't use an overly simple passphrase or increase the encryption rekey interval of your wireless AP (the default is generally 60 to 120 seconds, depending on your wireless AP). Small businesses and home offices should still consider setting up their wireless APs to allow connections only from machines registered with the WAP's media access control (MAC) address filter, which lets you manually identify your own machines. And perhaps most obviously, consider not broadcasting your wireless AP's Service Set Identifier (SSID), a unique name that publicly identifies the device. But if you do hide the SSID, be sure to change its name from the default (i.e., your Linksys wireless AP shouldn't be named "linksys").

I've been testing Wireless-G hardware at my home for a few weeks now and have been impressed with the performance and security of this relatively new technology. I'll be examining these devices in a future issue of Windows & .NET Magazine UPDATE, but if you're interested in my thoughts about the new Microsoft Wireless-G hardware, a review is available on the SuperSite for Windows at the following URL: http://www.winsupersite.com/article/reviews/microsoft-broadband-networking-wireless-g-review.aspx

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