Cisco 8821 Manual page 58

Configure Enable Session Timeout as necessary per your requirements. It is recommended to either disable the session
timeout or extend the timeout (e.g. 24 hours / 86400 seconds) to avoid possible interruptions during audio calls. If disabled it
will avoid any potential interruptions altogether, but enabling session timeout can help to re-validate client credentials
periodically to ensure that the client is using valid credentials.
Enable Aironet Extensions (Aironet IE).
Peer to Peer (P2P) Blocking Action should be disabled.
Configure Client Exclusion as necessary.
The Maximum Allowed Clients Per AP Radio can be configured as necessary.
Off Channel Scanning Defer can be tuned to defer scanning for certain queues as well as the scan defer time.
If using best effort applications frequently (e.g. VPN, etc.) or if DSCP values for priority applications (e.g. voice, video, call
control) are not preserved to the access point, then is recommended to enable the lower priority queues (0-3) along with the
higher priority queues (4-7) to defer off channel scanning as well as potentially increasing the scan defer time.
DHCP Address Assignment Required should be disabled.
Management Frame Protection should be set to Optional or Disabled.
Use a DTIM Period of 2 with a beacon period of 100 ms.
Ensure Client Load Balancing and Client Band Select are disabled.
Media Session Snooping can be enabled to utilize SIP CAC.
It is recommended to set Re-anchor Roamed Voice Clients to disabled as this can cause brief interruptions with wireless LAN
connectivity when a call is terminated after performing an inter-controller roaming.
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
58