The voice compression module must have enough resources available to process VComp bundles. The number of channels and the voice compression features that you enable on a bundle each consume processing resources on the module. Each module has a processing resource of 950 units. Table 1 shows the processing resources used by each compression technique and by each compression option.
For example, suppose you configure a VComp bundle with 16 channels and G.729AB compression, and you enable echo cancellation, silence suppression, fax/modem relay, and tone relay. You calculate voice compression usage as follows:
16 x (30 + 13 + 1 + 7 + 8) = 944
The outcome of 944 can be handled by one voice compression module if there are no other bundles using the module.
Table 1: Compression Options and Voice Compression Module Usage
Compression Technique | Rate/Channel | Compression | Echo Cancellation | Silence Suppression | Fax/Modem Relay | Tone Relay |
---|---|---|---|---|---|---|
PCM | 64 kbps | 3 | 6 | 1 | 5 | 4 |
MELP (Mixed Excitation Linear Prediction) | 2.4 kbps | 55 | 6 | 1 | 5 | 4 |
G.729.AB | 8 kbps | 30 | 10 | 1 | 8 | 7 |
G.728 | 16 kbps | 61 | 13 | 1 | 9 | 11 |
G.726_16K | 16 kbps | 13 | 7 | 1 | 5 | 5 |
G.726_24K | 24 kbps | 13 | 7 | 1 | 5 | 5 |
G,.726_32K | 32 kbps | 13 | 7 | 1 | 5 | 5 |
G.726_40K | 40 kbps | 13 | 7 | 1 | 5 | 6 |