Client Roaming; Edca Parameters - Cisco 8821 Manual

Client Roaming

The Cisco Wireless IP Phone 8821 and 8821-EX do not utilize the RF parameters in the Client Roaming section of the Cisco
Wireless LAN Controller as scanning and roaming is managed independently by the phone itself.

EDCA Parameters

Set the EDCA profile for Voice Optimized and disable Low Latency MAC for either 5 or 2.4 GHz depending on which
frequency band is to be utilized.
Low Latency MAC (LLM) reduces the number of retransmissions to 2-3 per packet depending on the access point platform, so
it can cause issues if multiple data rates are enabled.
LLM is not supported on the Cisco 802.11n/ac Access Points.
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
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