have you already gotten into the interoperability of Cisco 7921 phones with the 802.11i secured roaming techniques?
When acting with 3rd party infrastructure the handover delay is quite important. Despite the fact that the Pairwise Master key of a specific device association is distributed within all APs, Cisco 7921 phone repeats the authentication phase (EAP and TLS exchange) once associating to the new AP.
It's probably due to the fact that Cisco 7921 does not include a PMK ID in the RSN Information Element in the Re-Association Request frame.
Thank you for your feedback in advance.
Kind regards ,