ZyXEL Communications NWA-3550, User Manual

Page: 337 / 408

Appendix B Wireless LANs
NWA-3500/NWA-3550 User’s Guide
337
IEEE 802.1x
In June 2001, the IEEE 802.1x standard was designed to extend the features of
IEEE 802.11 to support extended authentication as well as providing additional
accounting and control features. It is supported by Windows XP and a number of
network devices. Some advantages of IEEE 802.1x are:
• User based identification that allows for roaming.
• Support for RADIUS (Remote Authentication Dial In User Service, RFC 2138,
2139) for centralized user profile and accounting management on a network
RADIUS server.
• Support for EAP (Extensible Authentication Protocol, RFC 2486) that allows
additional authentication methods to be deployed with no changes to the access
point or the wireless clients.
RADIUS
RADIUS is based on a client-server model that supports authentication,
authorization and accounting. The access point is the client and the server is the
RADIUS server. The RADIUS server handles the following tasks:
• 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 client and the network RADIUS server.
Types of RADIUS Messages
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.