Specifications

Cisco Unified Wireless IP Phone 7921G Series Deployment Guide 50
It is recommended to have the Cisco Unified Wireless IP Phone 7921G operate on the 5 GHz band due to have many channels
available and not as many interferers as the 2.4 GHz band has.
In order to utilize CCKM, enable WPA2 policy with AES encryption and 802.1x + CCKM for authenticated key management
type when the Cisco Unified Wireless IP Phone 7921G is running firmware version 1.3(4) or later in order to enable fast secure
roaming.
If the Cisco Unified Wireless IP Phone 7921G is running firmware version 1.3(3) or earlier, then enable WPA policy with TKIP
encryption and 802.1x + CCKM for authenticated key management type in order to enable fast secure roaming.