Wireless networking
Wireless networking provides some freedom while using a laptop or other portable device, but is not without its shortcomings. While it's convenient to not need to plug in a laptop to a wall port, the network connection is a lot slower than a wired connection, and much less secure.
Introduction
There are a few different types of wireless network connections, most referred to by the moniker "WiFi" or "802.11". The two most popular right now are "Wireless B" or "Wireless G", so named for their IEEE working group number 802.11b and 802.11g. A third soon-to-be-released version named 802.11n promises even more coverage and higher speeds than B and G, and a fourth earlier version 802.11a uses a different spectrum for less pollution but was not as widely deployed. You can currently buy many devices which will work on many of these four versions.
| Protocol | Release Date | Op. Frequency | Throughput (Typ) | Data Rate (Max) | Range (Indoor) | Range (Outdoor) |
|---|---|---|---|---|---|---|
| Legacy | 1997 | 2.4-2.5 GHz | 0.7 Mbit/s | 2 Mbit/s | ~Depends on walls | ~75 meters |
| 802.11a | 1999 | 5.15-5.25/5.25-5.35/5.49-5.71/5.745-5.825 GHz | 23 Mbit/s | 54 Mbit/s | ~30 meters | ~100 meters |
| 802.11b | 1999 | 2.4-2.5 GHz | 4 Mbit/s | 11 Mbit/s | ~35 meters | ~110 meters |
| 802.11g | 2003 | 2.4-2.5 GHz | 19 Mbit/s | 54 Mbit/s | ~35 meters | ~110 meters |
| 802.11n | September 2008 (estimated, currently at Draft 2.0) | 2.4 GHz and/or 5 GHz | 74 Mbit/s | 248 Mbit/s = 2x2 ant | ~70 meters | ~160 meters |
Security
Wireless networks are very insecure. While there are encryption protocols that were designed to make them more secure (WPA, WEP) they are flawed and only offer slight security against the unmotivated cracker. With very little effort, traffic can be sniffed and passwords recovered from a wireless network, unless you tunnel your traffic through some other end-to-end secure protocol such as a VPN, SSL or SSH. When using a wireless network, if you're not encrypting your traffic yourself (using only secure websites with SSL, routing traffic through a VPN, or using SSH tunnels) you should assume that anyone can (and is) watching all the traffic. You should never transmit passwords (such as through web forms, email, etc) unless you take the extra steps to tunnel your traffic in a secure manner.
The other side of security is authorization to use the network. While WPA keys provide the illusion of authorization (one must enter the key to be able to access the network), again they can be compromised. Many devices allow for a list of authorized MAC addresses which you can enter, limiting which devices can connect to the network even if the correct key is provided. This does add a little more protection, but even MAC addresses can be somewhat easily spoofed. When adding wireless networking to your home network, the best course of action is to firewall it separately from your wired network; not only do you want to protect the wireless users from the Internet, you want to protect your wired network from the wireless users.
Use in Princeton
Princeton has three wireless networks puwireless and puvisitor, which blanket most of campus (including many outdoor areas), and [eduroam], which isn't everywhere yet (but will be soon). If your device is registered on the network, you can use puwireless anywhere there is service. Visitors with unregistered devices can use puvisitor, but for no more than 7 days in a month or the device will be blocked. If you will be visiting longer, you should either use a wired connection with a NAT router, or if you will be around for quite a while then ask about having your laptop registered on the network. If all you need is wireless access, another option if you plan to be here for more than 7 days is eduroam. We have more details on eduroam on another page.
Also note that just because your device is registered for the wired network, that doesn't mean it will automatically work on wireless. When you submit your host registration, be sure to include both MAC addresses (and note which is which).
Wireless in Peyton
The campus wireless network covers all of Peyton Hall. Make sure to use the puwireless/puvisitor networks and not any others you may see (some people may accidentally turn on network sharing, or there may be a NAT router with wireless capabilities which haven't been turned off). Do remember that because wireless is an insecure connection, it falls outside the Peyton firewall; you will not be able to access printers or any other Peyton-only resources without first logging in via SSH to some wired computer on the network. If you must access some resource from your laptop, you'll have to plug it in first.
