Knowing the “ABGs” of Wireless Networking

Wireless networking is starting to become popular in the small-office environment. This article will explain the 3 different versions of wireless networking—A, B, and G—and which one is right for your office. OK, it is really 802.11a, 802.11b, and 802.11g. Since they are all 802.11 (industry standard numbering), this article will refer to them as A, B, and G. Each letter represents a different technology or subset of the industry standard for wireless networking—802.11.


Trying to decide which version is right for your office can be confusing at best. (The decision will be more confusing when a new version is released in the not-so-distant future.) The differences between the 3 versions are enough that you need to understand the variances between them and which one plays well with others. If you already have wireless networking installed, then your choices are limited by your current hardware and your willingness to buy new hardware. If you are looking to install wireless networking for the first time, then version G would be the best choice. This article addresses wireless networks in a small office. The wireless configuration for a large office or multiple buildings will differ greatly.

WHICH ONE IS THE FASTEST?
Versions A and G are rated at the same speed –54 Mbps­–while B is rated at 11 Mbps. Don’t worry if you don’t know what the Mbps stands for. You can see that A and G are almost 5 times faster than B. The 54 Mbps is great, but my broadband or DSL connection is not even close to that speed. So why should I get the A or G? You may not be able to take full advantage of the 54 Mbps, but you should see a difference in speed because of the improved technology in the A or G. The G version is the latest and greatest right now, but something better and faster will be released. That is how the technology cookie crumbles.

WHICH ONE HAS THE BETTER RANGE?
Version A is rated at roughly 25 to 75 ft. Versions B and G are rated at roughly 100 to 150 ft. The higher-end commercial products have a better range; the commercial products are also 3 to 4 times more expensive than the home- or small-office versions.


The location of the router or access point (AP) will greatly affect the range. If you put the router in the corner of your basement and try to access it from the second floor room at the other end of your office, you will probably get a weak signal or not get a signal at all. A weak signal also will translate to a slower connection speed. 

The ideal spot for the router is somewhere in the middle of all of the locations from which you will try to connect to the router. Think of the router as the hub of a bicycle wheel and the tire as being the circle from which you will try to connect to it. A safe bet is to use the middle to lower end of the range as your furthest point for placement of the router. 

Other factors should be considered when deciding to install wireless networking. If your office is close to television or radio towers, these may interfere with your wireless signal. Lead walls will diminish the signal and range, regardless of the version. The versions A and G operate on a 2.4 Ghz band. This is the same band that some cordless telephones use. Also, microwave ovens can cause interference with your wireless networking.

ARE THEY COMPATIBLE WITH EACH OTHER?
This is a major factor for those of you who currently have some wireless networking hardware. The simple answer is that B and G are compatible with each other, but A is not compatible with either B or G. An A wireless card will not connect to a G router, and a B wireless card will connect to a G router, but will be limited to the 11 Mbps connection speed. A G wireless card connecting to a B router also will be limited to the 11 Mbps connection speed. Some manufacturers offer dual-band routers that use both the A and G standards. This means that an A, B, or G wireless card can connect to this router. The connection speed limitation for the B card still comes into play. These dual-band routers are usually 2 to 3 times more expensive, so be sure you need this functionality before spending the extra money.

CAN I MIX AND MATCH HARDWARE FROM DIFFERENT VENDORS?
Maybe. How is that for a definitive answer? Most manufacturers claim that their products are compatible with other brands. This is true most of the time. But if you have a problem connecting your “Acme” wireless card to the “Meac” router, you may be caught in the middle of the finger-pointing game. The Acme support tech may blame the Meac router and the Meac tech may blame the Acme card. You don’t care which one is causing the problem, you just want the configuration to work.


My laptop has an internal wireless networking card that the manufacturer claims is its model. I have a wireless cable/DSL router from the No. 1 selling manufacturer. I cannot disable the broadcasting of my network name. My internal wireless network card loses its connection to the router as soon as broadcasting is disabled. Yes, they work together, but I am not thrilled about the lapse in security because of this issue.

I recommend that you stick to one manufacturer for all of your wireless hardware, if possible. This will make your life easier when a problem arises. Also, the release of new technology and standards may affect how these different brands work together.

WIRELESS SECURITY
If you read computing magazines, then you will see articles claiming that wireless networking is not secure and other articles stating it is secure. So, who is right?


Let me explain it this way. I believe that my car is secure when I lock the doors and leave it unattended in the parking lot. My colleague considers his car secure when he locks the doors, puts the “Club” on his steering wheel, and sets his car alarm. Thankfully, neither one of us has had our car broken into or stolen from the parking lot. Even with all of his security measures, an experienced car thief could steal his car. 

Applying this analogy to wireless networking, I implore you to be like my colleague. You should implement as many security measures as you can to protect your network. Your data is being transmitted through the air, which means it can easily be intercepted.

The degree of security does not come from the version letter. All 3 versions offer the same foundation for security. The degree of security comes from the configuration and settings that you set up for your router or access point. Also, the security options differ depending on the manufacturer and the model that you buy. The security configuration is performed on the wireless router or access point. You need to configure the client software (wireless network software in your PC) to use these configuration settings.

When you install the router onto your network, it is configured to be completely open (no security settings enabled). I know that this news is making a few of you sweat right now. There are more warning labels on a ladder than there are in your router instructions. The following are 5 security settings that you should implement to keep your wireless network secure.

Change the Default SSID
When you first install your wireless router, it is configured with a default network name (SSID). The default SSID is usually the manufacturer’s name. This SSID is basically the name for your wireless network. You should change the SSID to something that most people would not guess. For example, don’t change it to “dental,” “dentist,” “office,” your last name, etc. Using a name that has nothing to do with your practice makes it tougher for someone to know what network they are trying to hack into.

Disable SSID Broadcasts
The default setting is to broadcast the SSID. Even if you change the default SSID, it is not going to matter much if you are broadcasting the new SSID. The internal wireless network card in my laptop is set to connect to 6 different wireless networks. These networks are my network and client networks. When the card cannot connect to one of these networks, it listens for other wireless networks. This configuration is the default setting. I did not change any settings or install special software. If it hears the broadcast of a wireless network, it will tell me the name of the network and ask if I want to connect to this network. You would be amazed at how many wireless networks I find working in many different office buildings. Some of these networks have other security features implemented so I cannot connect, but many of them are wide open. If I can hear your wireless network broadcast, it means that I know I am in range, and know your SSID name.

Change the Default Password on the Administrator Account
The router has an administrator account that you use to log on to the router to make configuration changes. The router is configured with a default password – usually “admin.” If I can log into your router, I have full access to the wireless network settings. I could change the password and then change all of the settings so you cannot connect to the wireless network, but I can. The other bad news is that even if you can connect to the wireless router, I have changed the password so you can’t log in to change everything back. You would have to reset the router back to its factory default settings and then reconfigure it again for your network. Sure sounds easier to me to change the password first thing.

Enable MAC Address Filtering
Every network card (and most networking hardware in general) has a unique MAC address. This MAC address is unique worldwide. The manufacturer encodes this MAC address as part of the manufacturing process. Most of the time you cannot change the MAC address. One way to secure your wireless connection is to configure the router so that it will communicate only with specific MAC addresses. You would get the MAC address from each wireless network card and manually enter it into the router settings. You will need to enter the MAC address for each new wireless network card that you add to your network.

Enable WEP Encryption
Wired equivalent privacy (WEP) encryption means that the data you are sending through the air is all jumbled up. Even if someone were to intercept this data, they should only see garbage and the data would be useless to them. The other security feature with WEP is that you can make it mandatory, and you set the key. The key is set by using a specific number of characters depending on the level of encryption. The higher the level of encryption, the more characters you need and the slower your connection. The higher level creates more overhead when en­crypting and decrypting the data, so it slows down the transmission speed. You may not even notice this slowdown, so try the highest level first.


The router will change your WEP to a hexadecimal set of characters. I won’t bore you with the conversion to hexadecimal details, but you should know that whatever key you type on the router (along with the encryption level) needs to be typed on the client PC or laptop as well. So, if you make it unique, someone trying to hack into your network won’t be able to guess it.

I was at the local offices of a major software company recently for a seminar. When I turned on my laptop, it told me that a wireless network connection was available. I looked at the settings and noted that it was requiring WEP. I guessed the WEP key on the first try. It was the first set of letters in their SSID name. I needed to check e-mail and was grateful for the high-speed Internet connection.

CONCLUSION
If you currently have a version A wireless card or router, your options are limited unless you are willing to spend the extra money to buy all new equipment. The best bet for you may be to buy the dual-band router (both A and G) so you can buy the newer, cheaper version G products going forward.


If you don’t have any wireless equipment or have the version B hardware, purchasing the version G products is your best bet. You can use your current equipment and purchase the version G hardware going forward. Remember that your connection speed is as fast as your slowest link. If you have a version B router and all version G wireless cards, then your version B router limitation of 11 Mbps is limiting the G cards to the 11 Mbps. 

Try to stick with one manufacturer for all of your wireless hardware. Compare the features and security options available with each model when making your decision. The ease of setup and configuration will make your wireless experience a lot more enjoyable. 

You should implement the security settings as part of your initial configuration of the wireless network. If you don’t configure it from the start, you probably won’t go back to do it later. Why make it easy for people to connect to your wireless network? You should not minimize your security settings unless absolutely necessary because of hardware or connection problems.


Mr. Walsh is the owner of NDM Networks in Marlborough, Mass, which provides computer and networking services to dental practices and small businesses in Massachusetts and Rhode Island. He can be contacted at (508) 624-9898 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it .