G.722 And Isac Advertisement; Audio Bit Rates - Cisco 8821 Manual

The default DSCP value for SIP communications and phone configuration is set to CS3.
Phone based services are configured to be best effort traffic by default.

G.722 and iSAC Advertisement

Cisco Unified Communications Manager supports the ability to configure whether G.722 and iSAC are to be a supported codec
system wide or not.
G.722 and iSAC codecs can be disabled at the enterprise phone, common phone profile or individual phone level by setting
Advertise G.722 and iSAC Codecs to Disabled.

Audio Bit Rates

The audio and video bit rate can be configured by creating or editing existing Regions in the Cisco Unified Communications
Manager.
It is recommended to select G.722 or G.711 for the audio codec.
By default the video call bit rate is set to 384 Kbps.
For typical deployments, it is recommended to utilize 600p (1100-2000 Kbps) or HD 720p (1000-1599 Kbps) for the video
stream.
For enhanced video quality, set the video call bit rate to 1 Mbps to utilize HD 720p (total 1064 Kbps including G.722 audio).
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
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