Справочник Пользователя для LevelOne 11g PoE Wireless Access Point

Скачать
Страница из 108
Wireless Access Point User Guide 
94 
As Wireless Stations are physically moved through the area covered by an ESS, they will 
automatically change to the Access Point which has the least interference or best 
performance. This capability is called Roaming. (Access Points do not have or require 
Roaming capabilities.) 
Channels 
The Wireless Channel sets the radio frequency used for communication.  
•  Access Points use a fixed Channel. You can select the Channel used. This allows you to 
choose a Channel which provides the least interference and best performance. For 802.11g, 
13 channels are available in the USA and Canada., but 11channels are available in North 
America if using 802.11b. 
•  If using multiple Access Points, it is better if adjacent Access Points use different 
Channels to reduce interference. The recommended Channel spacing between adjacent 
Access Points is 5 Channels (e.g. use Channels 1 and 6, or 6 and 11). 
•  In "Infrastructure" mode, Wireless Stations normally scan all Channels, looking for an 
Access Point. If more than one Access Point can be used, the one with the strongest signal 
is used. (This can only happen within an ESS.) 
•  If using "Ad-hoc" mode (no Access Point), all Wireless stations should be set to use the 
same Channel. However, most Wireless stations will still scan all Channels to see if there 
is an existing "Ad-hoc" group they can join. 
WEP 
WEP (Wired Equivalent Privacy) is a standard for encrypting data before it is transmitted. This 
is desirable because it is impossible to prevent snoopers from receiving any data which is 
transmitted by your Wireless Stations. But if the data is encrypted, then it is meaningless 
unless the receiver can decrypt it. 
If WEP is used, the Wireless Stations and the Wireless Access Point must have the same 
settings. 
WPA-PSK 
Like WEP, data is encrypted before transmission. WPA is more secure than WEP, and should 
be used if possible. The PSK (Pre-shared Key) must be entered on each Wireless station. The 
256Bit encryption key is derived from the PSK, and changes frequently. 
WPA-802.1x 
WPA-802.1x - This version of WPA requires a Radius Server on your LAN to provide the 
client authentication according to the 802.1x standard. Data transmissions are encrypted using 
the WPA standard.  
If this option is used:  
•  The Access Point must have a "client login" on the Radius Server.  
•  Each user must have a "user login" on the Radius Server.  
•  Each user's wireless client must support 802.1x and provide the login data when required.  
•  All data transmission is encrypted using the WPA standard. Keys are automatically 
generated, so no key input is required.