ZyXEL Communications PLA-450 - V3.60, User Manual

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Chapter 6 Wireless LAN
PLA450 User’s Guide
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6.5.2 How WPS Works
When two WPS-enabled devices connect, each device must assume a specific role. One device
acts as the registrar (the device that supplies network and security settings) and the other
device acts as the enrollee (the device that receives network and security settings. The registrar
creates a secure EAP (Extensible Authentication Protocol) tunnel and sends the network name
(SSID) and the WPA-PSK or WPA2-PSK pre-shared key to the enrollee. Whether WPA-PSK
or WPA2-PSK is used depends on the standards supported by the devices. If the registrar is
already part of a network, it sends the existing information. If not, it generates the SSID and
WPA(2)-PSK randomly.
The following figure shows a WPS-enabled client (installed in a notebook computer)
connecting to a WPS-enabled access point.
Figure 30 How WPS works
The roles of registrar and enrollee last only as long as the WPS setup process is active (two
minutes). The next time you use WPS, a different device can be the registrar if necessary.
The WPS connection process is like a handshake; only two devices participate in each WPS
transaction. If you want to add more devices you should repeat the process with one of the
existing networked devices and the new device.
Note that the access point (AP) is not always the registrar, and the wireless client is not always
the enrollee. All WPS-certified APs can be a registrar, and so can some WPS-enabled wireless
clients.
SECURE TUNNEL
SECURITY INFO
WITHIN 2 MINUTES
COMMUNICATION
ACTIVATE
WPS
ACTIVATE
WPS
WPS HANDSHAKE
REGISTRAR ENROLLEE