ZyXEL Communications G-570S User Manual

ZyXEL G-570S User’s Guide

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Appendix C Wireless LANs

• Authentication 

Determines the identity of the users.

• Authorization

Determines the network services available to authenticated users once they are connected 
to the network.

• Accounting

Keeps track of the client’s network activity. 

RADIUS is a simple package exchange in which your AP acts as a message relay between the 
wireless station and the network RADIUS server. 

The following types of RADIUS messages are exchanged between the access point and the 
RADIUS server for user authentication:

• Access-Request

Sent by an access point requesting authentication.

• Access-Reject

Sent by a RADIUS server rejecting access.

• Access-Accept

Sent by a RADIUS server allowing access. 

• Access-Challenge

Sent by a RADIUS server requesting more information in order to allow access. The 
access point sends a proper response from the user and then sends another Access-
Request message. 

The following types of RADIUS messages are exchanged between the access point and the 
RADIUS server for user accounting:

• Accounting-Request

Sent by the access point requesting accounting.

• Accounting-Response

Sent by the RADIUS server to indicate that it has started or stopped accounting. 

In order to ensure network security, the access point and the RADIUS server use a shared 
secret key, which is a password, they both know. The key is not sent over the network. In 
addition to the shared key, password information exchanged is also encrypted to protect the 
network from unauthorized access.