Cisco 8821 Manual page 95

To utilize local RADIUS for infrastructure authentication, enable all authentication protocols.
Create a Network Access Server entry for the local access point.
Define the user account in which access points will be configured for to authenticate to the Wireless Domain Services enabled
access point.
Configure local RADIUS on each access point participating in Wireless Domain Services.
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
95