Cisco 9971 - Flexconnect Groups; Multicast Direct

Cisco Unified IP Phone 9971 Wireless LAN Deployment Guide
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FlexConnect Groups
All access points configured for FlexConnect mode need to be added to a FlexConnect Group.
If utilizing CCKM, then seamless roams can only occur when roaming to access points within the same FlexConnect Group.
Multicast Direct
In the Media Stream settings, Multicast Direct feature should be enabled.