Controller Settings - Cisco 8821 Manual

On the RF Profile tab, select the desired 802.11a or 802.11b RF Profile, then select Apply.
If changes are made after access points have joined the AP Group, then those access points will reboot once those changes are
made.
On the APs tab, select the desired access points then select Add APs.
Those access points will then reboot.

Controller Settings

Ensure the Cisco Wireless LAN Controller hostname is configured correctly.
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
60