Narrowband Codecs
The following tables contains the MPU values assigned per audio codec for one session. These values include all resources outlined in the audio base resource set. Note that the Spectre/Meltdown mitigations have impacted codec performance in some cases, and thus the ratio with G.711 has changed for certain codecs.
Base Resource Set with Codec |
Base Resource Set with Codec |
Bit Rate (Kbps) |
MPU per Session |
G.711 ulaw |
8000 |
64 |
1.0 |
G.711 alaw |
8000 |
64 |
1.0 |
G.726 @32 |
8000 |
32 |
1.8 |
G.729A |
8000 |
8 |
2.0 |
G.729AB |
8000 |
8 |
2.0 |
OPUS Constrained Narrowband |
8000 |
12 |
4.3 |
OPUS Narrowband |
8000 |
16 |
4.3 |
Base Resource Set with Codec |
Sample Rate |
Bit Rate (Kbps) |
MPU per Session |
G.722 |
16000 |
64 |
1.4 |
G.722.1 @24 (Siren) |
16000 |
24 |
1.5 |
G.722.1 @32 (Siren) |
16000 |
32 |
1.5 |
OPUS Wideband |
16000 |
20 |
6.8 |
If resources outside the audio base resource set are allocated, they will consume additional MPUs which need to be accounted for. Note that the base resource set includes the cost of SRTP/SRTCP encryption and decryption by default. The cost is already accounted for in the codec MPU values above.
