Saturday November 7th, 2009
Wireless Security and Performance - Important Information
Summary: Wireless networking is a shared technology and is inherently insecure. Use the guidelines below to make your connection more secure.
Important Notices
- Telnet service from UCInet Mobile Access is blocked.
An SSH Client will provide the same functionality, securely. - Peer to Peer (P2P) Not Allowed Over the Wireless
Network
Peer to Peer (P2P) applications (examples include BitTorrent, eMule, Kazaa, and Gnutella) are not allowed on the UCInet Mobile Access Network. The wireless network is a shared network, running at slower speeds than most other UCInet connections. If you are taking up large amounts of bandwidth, you are negatively affecting the performance of all other users. Using excessive bandwidth may cause you to lose wireless networking privileges at UCI.
Security
UCInet Mobile Access wireless networks use a wireless technology known as IEEE 802.11. This is a shared network technology. Like all shared networks, these networks should be presumed insecure.
Shared Network
A shared network is like a dinner party - anyone can eavesdrop
on your conversation, if they know how. Sophisticated network
sniffing tools make it possible for others to look at network traffic,
and capture data in-transit.
- Use secure, encrypted sessions (such as SSH in place of telnet, or https/SSL for online transactions) whenever transmitting sensitive information.
- For insecure transactions, use the campus VPN (Virtual Private Network, an encrypted tunnel) or use a switched wired network. Note: The campus VPN only works from the UCInet Mobile Access wireless network.
Authentication for UCI Affiliates
UCInet Mobile Access uses an authentication scheme based
on MAC addresses (see also, What is a MAC Address).
For additional information, please see the web page for (UCInet
Mobile Access Details).
Performance
Shared Bandwidth
UCInet Mobile Access is a shared network, and like all
shared shared networks, users on it share bandwidth. The means that everyone
is drinking from the same straw; if you download large amounts
of data,
you are making the network much slower for everyone else. Please
be sensitive to this issue, and save downloads of more than a
few seconds for a switched, wired network.
Correctly configuring your wireless client is important for best performance. For optimal performance, set the "Distance between Access Points" setting on your wireless interface card to match the geographical location. The table below (Table 1) is provided as a reference.
|
Table 1: Locations and Wireless Client-Manager
Distance Settings. |
|
| Gateway Commons | Small |
| GSM, Floors 1 and 2 | Small |
| GSM, Floors 3 and 4 | Large |
| Main Library | Large |
| Student Center | Large |
| Engineering Gateway - 1st Floor | Large |
Overlap in Wireless Zones
When 802.11 wireless access points are close
together, their radio-frequency
"energy spheres" overlap, and it is possible to have your wireless
laptop "see" two or more of them at the same time. In general,
your laptop will make the best decision and automatically choose the
access point which offers the best connection.
Sometimes, however, it is possible for the software controlling your 802.11 wireless card to become confused, when you are in overlapping zones where the access points are closer together. In these cases, OIT has found that setting the client manager software for the wireless card to a 'small' distance between access points effectively clears this up. Be sure to set it back to 'large' when you are in more open areas.
