ZyXEL Communications ZyAIR G-3000, User Manual

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ZyAIR G-3000 User’s Guide
71 Chapter 5 Wireless Configuration and Roaming
5.6 Configuring Roaming
A wireless station is a device with an IEEE 802.11b or an IEEE 802.11g compliant wireless
inteface. 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 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 access
points on the LAN about the change. The new information is then propagated to the other
access points on the LAN. An example is shown in
Figure 27 .
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).