ZyXEL Communications G-570U, User Manual

Page: 142 / 162

ZyXEL G-570U User’s Guide
142 Appendix C Wireless LANs
If the roaming feature is not enabled on the access points, information is not communicated
between the access points when a wireless station moves between coverage areas. The
wireless station may not be able to communicate with other wireless stations on the network
and vice versa.
Figure 110 Roaming Example
The steps below describe the roaming process.
1 As wireless station Y moves from the coverage area of access point P1 to that of access
point
2 P2 , it scans and uses the signal of access point P2 .
3 Access point P2 acknowledges the presence of wireless station Y and relays this
information to access point P1 through the wired LAN.
4 Access point P1 updates the new position of wireless station.
5 Wireless station Y sends a request to access point P2 for re-authentication.
Requirements for Roaming
The following requirements must be met in order for wireless stations to roam between the
coverage areas.
1 All the access points must be on the same subnet and configured with the same ESSID.
2 If IEEE 802.1x user authentication is enabled and to be done locally on the access point,
the new access point must have the user profile for the wireless station.
3 The adjacent access points should use different radio channels when their coverage areas
overlap.
4 All access points must use the same port number to relay roaming information.