Polycom RealPresence 1500 Administrator's Manual page 254

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Siren22, G.719 and SirenLPR Mono vs Bitrate
Audio Algorithm
Siren22 64k
Siren22 48K
Siren22_32k
G.719_64k
G.719_48k
G.719_32k
G.728 16K
G.719_64k
SirenLPR_48k
Siren22_48K
G.719_48k
G.7221C_48k
Siren14_48k
SirenLPR_32k
Siren22_32k
G.719_32k
G.7221C_32k
Siren14_32k
SirenLPR
SirenLPR
SirenLPR
Stereo
The Siren 22Stereo, G.719Stereo and SirenLPR audio algorithms are supported at the following bit rates.
Siren22Stereo, G.719Stereo and SirenLPR vs Bitrate
Audio Algorithm
Siren22Stereo_128k
SirenLPRStereo_128k
G.719Stereo_128k
Polycom®, Inc.
Additional Conferencing Information
Minimum Bitrate (kbps)
384
384
256
128
64
48
32
Minimum Bitrate (kbps)
1024
224