ZyXEL nbg-334w Guia Do Utilizador

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 Chapter 5 Wireless LAN
NBG334W User’s Guide
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It is recommended that wireless networks use WPA-PSKWPA, or stronger 
encryption. IEEE 802.1x and WEP encryption are better than none at all, but it 
is still possible for unauthorized devices to figure out the original information 
pretty quickly.
It is not possible to use WPA-PSKWPA or stronger encryption with a local 
user database. In this case, it is better to set up stronger encryption with no 
authentication than to set up weaker encryption with the local user database.
When you select WPA2 or WPA2-PSK in your NBG334W, you can also select an option 
(WPA Compatible) to support WPA as well. In this case, if some wireless clients support 
WPA and some support WPA2, you should set up WPA2-PSK or WPA2 (depending on the 
type of wireless network login) and select the WPA Compatible option in the NBG334W.
Many types of encryption use a key to protect the information in the wireless network. The 
longer the key, the stronger the encryption. Every wireless client in the wireless network must 
have the same key. 
5.3  Roaming
A wireless station is a device with an IEEE 802.11a/b/g compliant wireless interface. An 
access point (AP) acts as a bridge between the wireless and wired networks. An AP creates its 
own wireless coverage area. A wireless station can associate with a particular access point 
only if it is within the access point’s coverage area.
In a network environment with multiple access points, wireless stations are able to switch from 
one access point to another as they move between the coverage areas. This is known as 
roaming. As the wireless station moves from place to place, it is responsible for choosing the 
most appropriate access point depending on the signal strength, network utilization or other 
factors.
The roaming feature on the access points allows the access points to relay information about 
the wireless stations to each other. When a wireless station moves from a coverage area to 
another, it scans and uses the channel of a new access point, which then informs the other 
access points on the LAN about the change. An example is shown in 
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With roaming, a wireless LAN mobile user enjoys a continuous connection to the wired 
network through an access point while moving around the wireless LAN.
Enable roaming to exchange the latest bridge information of all wireless stations between APs 
when a wireless station moves between coverage areas. Wireless stations can still associate 
with other APs even if you disable roaming. Enabling roaming ensures correct traffic 
forwarding (bridge tables are updated) and maximum AP efficiency. The AP deletes records 
of wireless stations that associate with other APs (Non-ZyXEL APs may not be able to 
perform this). 802.1x authentication information is not exchanged (at the time of writing).