Wireless Networks: What To Know

Wireless networks are inherently insecure and slow because they are shared networks. They are slower than a switched network, like the Engineering Computer Network (ECN) in the Seamans Center. Nevertheless, there are reasons that people use wireless networks; for example, they exist in many places, more all the time, and are convenient. If you use a wireless network, you should know enough to make your transactions as secure as possible.

Being As Secure as Possible

In early 2005 CSS installed new wireless access points (APs) that support the 802.11a, b, and g standards; the a and g standards are faster (54 megabits per second or Mbps) and more secure (supports Wireless Protected Authentication or WPA) than the b (11 Mbps) standard. The campus uses the 802.11b and g standards.

What To Do at Home

Although a wireless network is not secure in part because anyone with the necessary wireless card can use your wireless network (and so abuse that connection), wireless networks in private homes are not as likely to be used by uninvited users. Nevertheless, wireless networks are not secure, so do the following to afford yourself as much protection as possible.

Set the antenna power to the lowest possible threshold to cover the necessary area, if that is an option.
Enable the WEP key on your access point (AP) and computer(s).
Enter your MAC address when setting the network and filter by MAC address.
Enter your password and other sensitive data only on locked pages (web pages will have a fastened padlock on the page when using a secure connection). Use sftp (secure file transfer protocol) to transfer files.
Email users: Set your email client Thunderbird to use a secure connection as described on the configuration pages for those clients. Webmail is secure.

Shared vs. Switched, and other Technical Details

Wireless networks are shared, meaning that everyone with a wireless card in a computer is using the same channel for all transactions. CB radios, walkie-talkies, telephone party lines (for those who remember), and pagers work the same way. You can hear conversations that other users on the same channel are having. In contrast, cell phone networks are not shared, though some people talk so loudly enough to share their side of the conversation. When you turn on your phone and call, you hear only the connection you make (point to point) with the person you called. The cell phone networks use a different virtual channel for each call.

Because wireless networks are public, everyone (computers) using the network can read all the traffic that passes on the network. In practice most people using computers on a wireless network are doing their own work. But malicious people also use wireless networks to steal the transmitted information.

By way of contrast and fyi, the ECN is a switched, point-to-point network. On the ECN information that flows along the path between your computer and the servers is readable only by the sending and receiving machines. Because the path is not open and shared, as in a wireless network, transmitted information is secure. The ECN is faster than the wireless networks because it runs at 100 megabit full duplex (meaning that both the sender and the receiver can talk at the same time); wireless networks run at 11 megabit half-duplex (meaning that only the sender or the receiver can talk), with actual throughput less than 5 megabit.

The College of Engineering wireless network, like most University wireless networks, runs on the 2.4 GHz band. The University has designated that the 2.4 GHz band gets priority for networking. You cannot operate cordless phones, a web cameras, or any other device that runs in the 2.4GHz spectrum on campus.

Terminology

(Definitions courtesy of Webopedia)

WPA - Wireless Protected Authentication/Access; definition

MAC - Media Access Control; definition

AP - Access Point; definition

Help

If you need help or advice about setting up a wireless network at home, call CSS, 319-335-5751, 1256 SC.

Read about using the wireless network in the Seamans Center.

updated: 27 May 2006