Although this Tech Tip is by no means an exhaustive resource on configuring a wireless network, it will provide information and pointers that can be applied to most typical installations. Many of these tips are general enough that they may provide some good advice for those utilizing wired networks as well.

For the sake of this article, we will assume that the hardware has been successfully installed physically, and that the user is now prepared to set up and secure the system through software. Wireless devices, especially routers / access points, generally include a web-based configuration utility that allows the user to customize the hardware to meet their needs. The hardware will most likely work with minimal configuration, but to make it work so that the integrity of the network is protected may take a few more steps.

In addition to the configuration interface provided with the wireless networking hardware, Microsoft has integrated a “Wireless Network Setup Wizard” with the release of Windows XP Service Pack 2 that will lead a user of any expertise through the installation of their network. In addition, the “Microsoft Broadband Network Utility” will help them monitor and maintain the network just as easily once it is set up.

First, change the default SSID to a unique name that includes a combination of letters and numbers that doesn’t reveal anything personal about you or your network. Second, disable the broadcast of the SSID once all of your computers are successfully connected, even if your router / access point recommends broadcasting it. I have used a few wireless routers, and all of them have a check box in the control panel for enabling/disabling the broadcast of the SSID, and they have all recommended leaving broadcasting enabled. Broadcasting the SSID allows new computers to easily find your network, and then all they have to do is access it given the proper credentials. Broadcasting your SSID puts it out there for anyone within range to see, and it just allows would-be hackers to get one step closer to compromising your security. In a home environment, there are probably few computers that need to access the network, and if more are ever added, you can temporarily enable the broadcast to get them set up.

One method, and the best as far as security is concerned, is to disable the DHCP server. This will require that all computers that are authorized to connect to the network be configured manually, but it will prevent unauthorized computers from obtaining an IP address. The second method, which doesn’t provide bulletproof security, is better than doing nothing. In general, a DHCP server can support up to 250 computers, and by default leaves a range of addresses readily available for that many to connect. If disabling the DHCP server doesn’t seem convenient for a user, they can limit the DHCP server to only provide as many IP addresses as they know they need. If you know there will never be more than five computers connected, limit the range of available IP addresses to a total of five within the configuration utility.

WEP, or Wireless Equivalency Protocol, was the first format of encryption available on wireless networks. WEP allows the network administrator to assign an encryption string to be shared by all computers authorized to access the wireless network. The encryption through WEP is either 64bit, 128bit, or 256bit, where the higher number represents greater encryption, and the strings can be generated by the administrator as a series of letters and numbers.

WPA, or “Wi-Fi Protected Access,” is an improvement over WEP that starts off with a similar master encryption string and then mathematically derives encryption keys to keep the security dynamic. WPA continually changes the encryption keys used for each packet of data, and due to the extra processing required to support this protocol the overall throughput of the connection may suffer slightly. Despite the potential for decreased speed, WPA is considered to be far more robust than WEP, and should be implemented where possible. In some instances, WEP encryption has actually been defeated, making WPA all that more appealing.

Although most components support both of these encryption formats, and users can select the type they wish to use from within the control software, not all do. All devices on the network must be set to operate at the same level of encryption, which may mean that some devices will force others to be less secure than they are capable of. For example, a wireless network setup around this router could support either WEP or WPA encryption. When two computers are added to this network using one of these network adaptors in one case, and one of these network adaptors in the other case, things change. Note that the second adaptor does not support WPA; therefore the whole network must now be configured to use WEP to accommodate it.

As mentioned, 802.11b and 802.11g networks operate on a 2.4 GHz radio band, which gives a much greater range as compared to 802.11a. One downside to being on the 2.4 GHz band is that many devices share it, and interference is bound to be an issue. Cordless phones and Bluetooth devices are two of many items that operate at this frequency. The range of these two protocols is about 300 feet in free air, and the difference between the two comes down to speed. 802.11b came first, released back in 1999, and offers speeds up to 11 Mbps. 802.11g first appeared in 2002 and it is a backwards compatible improvement over 802.11b and offers speeds up to 54 Mbps.

On top of these protocols, some manufacturers have improved upon the 802.11g standard and can provide speeds of up to 108 Mbps. This doesn’t involve a separate protocol, but just a bit of tweaking in areas like better data compression, more efficient data packet bursting, and by using two radio channels simultaneously. Typically, stock 802.11g equipment is not capable of these speeds, and those interested need to shop for matched components that specify 108 Mbps support. I say “matched components” as this is not a standard protocol and the various manufacturers may take different approaches to achieving these speeds. In order to ensure the best results when trying to achieve these elevated speeds, components from the same manufacturer should be used together. For instance, only Netgear brand network adaptors rated for 108 Mbps data transfer should be used with something like the Netgear WG624 wireless router.

Considering your typical broadband Internet connection is going to offer data transfer rates of 10 Mbps or less, it can be seen that even 802.11b would be more than adequate if you just want to surf the web. Sharing files on your LAN (Local Area Network) is where the faster protocols will really make a difference, and comparing the prices of 802.11b and 802.11g components may show that there is little to no difference in selecting a “g” capable device over a comparable “b” capable device.

Router

Network Adaptor – A network adaptor is required for every computer that you would like to be connected to the wireless network. Many laptops, such as this Sony Centrino 1.5 GHz now include a wireless adaptor built in, so no extra hardware is needed. For those with systems that don’t have wireless capabilities built in, adding them is fairly simple, and can be done using a variety of connections. Desktop computers can go wireless by adding a PCI slot network adaptor such as the 802.11g capable D-Link DWL-G510. Notebook users can easily add wireless connectivity by using a PCMCIA adaptor, such as this 802.11g capable device. And for truly convenient plug-n-play connectivity to wireless networks, USB adaptors such as this 802.11g capable dongle are available.
Antenna/Extender – These items are not essential, but given the specifics of a wireless environment, they may be helpful. Devices such as the Hawking Hi-Gain Antenna or the Super Cantenna serve the purpose of increasing the wireless signal strength, and therefore extend the range of a given wireless network. Not only can a large area of open space be covered, but the signal quality may be improved in structures with walls and floors that obstruct the signal transmission.