What You Should Know About the Wireless Network
by Michael Landry, Quinnipiac Network Support

Quinnipiac University has installed a large wireless network on campus to provide easy access to network-based and Internet-based resources. Coverage includes most classrooms and some of the residence halls and common areas. Following is a discussion of basic guidelines users should understand to get the most benefit from the wireless network.

The wireless network meets specific technical standards set by a network-industry group. Quinnipiac University has chosen the most compatible hardware for our network, and included that hardware in the Dell laptops purchased through the Dell Laptop Purchase Program. Quinnipiac University officially supports only the Dell laptops and their included wireless cards, and does not support other brands of hardware.

Wireless coverage is prevalent around the Quad areas, and most classrooms have coverage. In the summer of 2005, QU added wireless to Perlroth, Larson, and Troup halls as the primary connection method for students in those halls.

It’s important to understand some basics on how wireless works. When you connect to the wireless network, your laptop initiates a connection to a wireless “access point” (AP) somewhere within range. This is similar to the way you might call out vocally (wirelessly, through the air) to a professor when you respond to a question. Using this same model, multiple laptops can connect to a single AP, in the same way that a whole class of students communicates with a teacher.

Now think about this: If everyone in your class spoke to the teacher at once, would your professor be able to pick out each person’s conversation, and understand everyone? Wireless access points work the same way. If multiple laptops transmit data at the same time, the AP can’t distinguish between the signals from each laptop.

The important point here is that wireless APs provide a “shared medium.” That is, only one laptop can use any given AP at a time. Normal “wired” connections don’t have this problem; wired networks can handle many computers communicating at once. The result is that the wireless access point, like your professor, can only speak so fast. Access points are slower than wired connections, so that any capacity is shared by everyone using the AP. By comparison, the wired connections on campus run at least twice as fast, and you don’t have to share that speed with anyone! For this reason, the wired network usually provides a faster, more reliable connection to network resources.

As mentioned above, other factors contribute to the speed and reliability of a wireless network connection. The wireless network operates in the “2.4 Gigahertz” range; this may sound familiar since most cordless phones operate in this same range. To return to our parallel about the classroom, imagine now that while everyone is trying to talk to the teacher, one of your fellow students is sitting outside the classroom with his car’s audio system cranked up loud enough to be heard clearly in the classroom. Even if you and the teacher are talking one on one, you may still have to repeat yourself for the teacher to hear you.

Another important point here: other devices that operate in the same 2.4-gigahertz range will interfere with the wireless network and cause a slowdown (sometimes even an interruption) in your wireless connection.

Guess what? Microwaves operate in the 2.4-gigahertz range, so your roommate making popcorn can kill your wireless signal. Does your cell phone have Bluetooth? You guessed it, 2.4 gigahertz. Did your roommate bring his or her own wireless access point to campus and set it up? Not only is it going to hurt your connection, but also it will negatively affect those people around you, including users on the official Quinnipiac access points. While we can’t eliminate all of these kinds of devices from use, understanding the potential problems here can help keep the situation in hand.

Hopefully you haven’t stopped reading already! There’s some security information that you need to understand, too. Your wireless communications can be heard (and recorded!) by anyone within range of your laptop. If you were in a classroom, would you shout your credit card number to your professor? Of course not. Take it one step further: if a student puts up her own wireless access point in her residence hall room, and you use it to get on the network, that student now has complete access to everything you transmit over the wireless network! This is similar to someone tapping your phone line; you have no secrets anymore.

To combat these problems, Quinnipiac University has taken a number of steps to help secure your information. We require all wireless communications to use an encryption standard known as WEP, or Wired Equivalency Protocol. This encrypts all the traffic between your laptop and the wireless access point. Unfortunately, the WEP standard has been shown to have critical flaws that could allow someone to decrypt your information. (Soon we’re going to change this security method to one that is more secure.) The bottom line is to keep any private information off the wireless network.

The issue of personal wireless access points (known as “rogue” APs) is tougher to address, but that process is under way. The interference caused by these devices negatively affects the signal of Quinnipiac’s wireless network, even when located in another building. As mentioned above, rogue APs also present a security risk to you and your information. We use network tools that scan the airwaves and provide the location of these rogue APs. Any rogue APs found are turned off. The Student Handbook also explains that this activity is not allowed (see page 86).

There is another layer of protection in place. Quinnipiac has installed a traffic management solution that looks at both the type and the amount of traffic that a laptop transmits to the wireless network. If the traffic from a laptop crosses certain thresholds where it is affecting the quality of other users’ connections, this management device uses technical means to prevent the offender from using the wireless network. Once the malicious activity has ceased for 10 minutes, they are allowed back on the wireless network.

Normal types of network traffic, such as email, web surfing, Blackboard, and instant messenger will not trigger your removal from the network! However, file-sharing and peer-to-peer software over a wireless connection is not allowed. It is normal for file sharing software to open 400 – 600 outgoing connections at once. Imagine if a student in your class decided to stand up and say 600 things to the professor; you would never get a turn to speak! If you wish to use peer-to-peer programs, you can still do so over a normal wired connection.

Check to see if you have file-sharing programs set to start automatically when you boot your laptop. If you turn on your laptop in class and a P2P application starts, you may be removed from the network and unable to access your homework or a quiz. If we don’t remove these problems from the network, your laptop can prevent the other users in the classroom from being able to take their tests, which isn’t fair to them.

Do you use FaceBook.com? Performing a search in FaceBook frequently opens up 200 or more outgoing connections to dozens of FaceBook servers on the Internet. Consequently, we advise you to use Facebook over a standard wired connection in place of the wireless network.

We are constantly testing various applications to see how they affect wireless network connections. Currently, we know that the traffic generated by the following applications will cause you to be removed from the wireless network: BitTorrent, Kazaa/Gnutella/LimeWire/etc., myTunes, and most other peer-to-peer software.

If you have been removed from the network, when you open a web browser, you will see a message displayed informing you that your computer has been temporarily removed from the wireless network. Try shutting down any programs other than the minimums you need for your work, and try again in 10 minutes.

The bottom line is that while wireless is a convenient way to access network-based resources, you should remember that wireless:

  >  is a shared medium subject to interference;
  >  is not suitable for all types of network traffic;
  >  should not be used for critical communications, e.g. online banking and purchasing. 

The Quinnipiac wireless network is going to continue to grow. As the industry continues to advance, reliability and security will continue to improve as well, allowing us to roll out new services over wireless.

I hope you find this article helpful. Please feel free to submit any questions or feedback to us via the Help Desk Request Form at http://helpdesk.quinnipiac.edu/request/.

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