Cisco 8821 Manual page 94

First, define the server group to be used for infrastructure authentication.
Is recommended to use local RADIUS for infrastructure authentication.
If not using local RADIUS for infrastructure authentication, then need to ensure that all access points with Wireless Domain
Services enabled are configured in the RADIUS server.
Then, define the server group to be used for client authentication.
Will need to ensure that all access points with Wireless Domain Services enabled are configured in the RADIUS server.
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
94