Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual page 281

18.1.4 Tips and Tricks for Setting Up a
WLAN
These tips can help tweak speed and stability as well as security aspects of your WLAN.
Stability and Speed
The performance and reliability of a wireless network mainly depend on whether the
participating stations receive a clean signal from the other stations. Obstructions like
walls greatly weaken the signal. The more the signal strength sinks, the more the
transmission slows down. During operation, check the signal strength with the iwconfig
utility on the command line (Link Quality field) or with NetworkManager or
KNetworkManager. If you have problems with the signal quality, try to set up the devices
somewhere else or adjust the position of the antennas of your access points. Auxiliary
antennas that substantially improve the reception are available for a number of PCMCIA
WLAN cards. The rate specified by the manufacturer, such as 54 Mbit/s, is a nominal
value that represents the theoretical maximum. In practice, the maximum data
throughout is no more than half this value.
Security
If you want to set up a wireless network, remember that anybody within the transmission
range can easily access it if no security measures are implemented. Therefore, be sure
to activate an encryption method. All WLAN cards and access points support WEP
encryption. Although this is not entirely safe, it does present an obstacle for a potential
attacker. WEP is usually adequate for private use. WPA-PSK would be even better, but
it is not implemented in older access points or routers with WLAN functionality. On
some devices, WPA can be implemented by means of a firmware update. Furthermore,
although Linux supports WPA on most hardware components, some drivers do not offer
WPA support. If WPA is not available, WEP is better than no encryption. In enterprises
with advanced security requirements, wireless networks should only be operated with
WPA.
Wireless Communication 267