ZyXEL Communications G-220 v3 User Manual

ZyXEL G-220 v3 User’s Guide

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Chapter 3 Wireless LAN Network

Figure 22   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.
By default, a WPS devices is “unconfigured”. This means that it is not part of an existing 
network and can act as either enrollee or registrar (if it supports both functions). If the registrar 
is unconfigured, the security settings it transmits to the enrollee are randomly-generated. Once 
a WPS-enabled device has connected to another device using WPS, it becomes “configured”. 
A configured wireless client can still act as enrollee or registrar in subsequent WPS 
connections, but a configured access point can no longer act as enrollee. It will be the registrar 
in all subsequent WPS connections in which it is involved. If you want a configured AP to act 
as an enrollee, you must reset it to its factory defaults.

This section shows how security settings are distributed in an example WPS setup.
The following figure shows an example network. In step 1, both AP1 and Client 1 are 
unconfigured. When WPS is activated on both, they perform the handshake. In this example, 
AP1 is the registrar, and Client 1 is the enrollee. The registrar randomly generates the security 
information to set up the network, since it is unconfigured and has no existing information.