Wi-Fi, some thoughts.


What is Wi-Fi? At its heart, Wi-Fi is a way to allow computers to communicate with each other without the use of a physically wired network. In other words, a computer equipped with wireless technology can talk to other computers (and usually the Internet) without being physically plugged in to any wires.

For all intents and purposes, a Wi-Fi connection uses the same “rules” to talk to other computers as a wired connection does. This is what allows both wired and wireless computers to communicate over different kinds of connections; they’re both speaking the same “language”.  However, the wireless standard is continuously evolving, and so there are several different types of wireless connections currently in use.

Wi-Fi standards and types are defined by IEEE 802.11. Don’t worry too much about all those letters and numbers, the average consumer doesn’t really need to know that information. For the sake of this article, however, I will simply say that the IEEE is the organization that defines all of the standards on how computers communicate with each other (among many other things). Currently there are four different types of the 802.11 standard: A, B, G, and N. Starting at A and moving on through the alphabet, each of these standards represents an improvement in either the range or speed of a Wi-Fi connection. The A and B standards are quite old, and as such you will rarely see them, much less use them in an office environment. The G and N standards are most commonly used today, with N gradually gaining ground on G. However, most Wi-Fi cards and routers are backwards compatible with previous versions, so if you are buying a new laptop/router, then you will want to purchase the most advanced standard possible, which currently is N.


Wireless Security

The very thing that makes Wi-Fi so useful is also the thing that is its greatest drawback, namely, the lack of a physical connection. With a traditional wired network, your data is travelling over a copper wire between computers. This makes it fairly difficult to view the data that is passing back and forth around your practice/office, at least not without an eavesdropper being fairly obvious about tapping into your network. However, with a wireless network, all of your data is going out over the air, where anyone with the right equipment can pick it up and read it, quite often from a concealed location like the parking lot or the next building over. So while a wireless network can be useful, it can also be a huge liability, especially taking HIPAA into account. I’ve lost track of the number of offices I’ve walked into that were passing patient data over a completely unsecured wireless network, free to anybody who cared to listen in.

So what can you do to make Wi-Fi a viable option? The short answer is: Lots! The first thing to be aware of is that every Wi-Fi network has something called an SSID (Service Set Identifier). This is basically just the name of the network. By default this SSID is broadcast to everyone and everything within the range of the wireless router. Think of it as your router continuously yelling: “Here I am, this is me, this is my network, come join me!” Anyone with a wireless card can see your network, and attempt to connect to it. Thankfully, there is an easy way around this. Almost all Wi-Fi routers allow you to conceal the SSID, so that only by manually entering in the SSID on each client/workstation can you connect to the wireless network. It takes special software or hardware to be able to see a concealed SSID, things that most casual eavesdroppers will not have.

So concealing the SSID is the first step to securing your wireless network. The next step is to encrypt all of the data travelling over the network. Encryption is a way of making it so that even if an outsider manages to see the network, he or she will not be able to determine what the data passing over the network actually is. There are several different ways to encrypt your data. Let’s start at the low end of the spectrum.

The lowest form of wireless encryption is WEP, or Wired Equivalent Privacy. As the name implies, it’s simply an attempt to make your wireless traffic as secure as your wired traffic, which is not very. An eavesdropper with the proper tools can break WEP encryption in less than 5 minutes. So WEP is better than nothing, but not by much.  The next step up is WPA (Wi-Fi Protected Access), available in several different “flavors”. WPA was designed to be used as a stopgap measure to counteract the known problems with WEP. Unfortunately, there are now several known methods of breaking WPA, and so it shouldn’t be considered completely secure. Finally we have WPA2, which—assuming you’re using a good password—is considered effective security.  All modern Wi-Fi routers can support WPA2, as well as all modern wireless network cards, so therefore WPA2 is what should be used in order to keep the wireless network as secure as possible.

There is one final element that can be used to secure a wireless network, and this element is called MAC address filtering. Every computer connected to a network has a unique identifier (well, USUALLY unique, but that’s a topic for another time) called a MAC address. Since this identifier is unique, you can use it to control access to your network. Almost all modern Wi-Fi routers can be configured to allow access to only those computers that you identify by MAC address, denying all others.


Should you use it?

Now that we’ve determined that we can make our wireless network relatively secure, should it then be used as a dental office network? The answer here, like so many things, is yes and no, but mostly no. It is definitely technically possible to use only wireless as your office network, but it’s not generally recommended for the following reasons. First, Wi-Fi can be notoriously fickle in how well its signal propagates through a building. Internal walls (especially with a lot of metal in them), furniture, and other wireless signals can all interfere with and degrade a wireless signal. Second, a properly wired network with a gigabit switch is much faster than a wireless network, even without taking into account wireless signal degradation. Finally, and perhaps most important, a Wi-Fi signal can sometimes cut out briefly without warning. If you are just surfing the internet you probably wouldn’t notice, but if your computer is connected to any sort of database (like just about any Practice Management Software) this can lead to data and/or database corruption. To my mind, this is not a risk worth taking simply to be able to move a laptop around the office.

So if I’m not recommending Wi-Fi for office use, what good is it? Well, Wi-Fi may not be good for your office’s medical use, but it can be great for patients to use in the waiting room. My recommendation is to create an open or mildly secured wireless network that is completely separate from your office’s network. Your patients can then connect to this network with their smart phones or laptops as they wish. Most higher-grade internet firewalls (which you should definitely look into using if you aren’t already) support this kind of functionality. Using this method your data is secure, and your patients are happy, it’s a win/win situation!

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