Selecting The Proper Voice Compression - MCK EXTender PBXgateway System Administrator Manual

Selecting the Proper Voice Compression

The best voice quality is achieved by using the ADPCM 32 compression. The maximum quality comes at
the expense of the highest utilized bandwidth. The largest voice compression is achieved by using
G.729A. If you are using this algorithm, you will save on bandwidth and still achieve voice quality that is
regarded as near toll. If absolute conversation quality is your focus and bandwidth is no object, you
probably want to select ADPCM 32. If bandwidth is a priority you will employ G.729A.
If you are using different compression algorithms for each individual user (port), use the following formula
to establish your aggregate data bandwidth needs.
A B C D
x 16 + x 32 + x 40 =
A: number of G.729A
B: number of ADPCM 24
C: number of ADPCM 32
D: Total Bandwidth
Divide this bandwidth by either 64 or 56, in order to establish the correct number of DS0 channels to be
used.
Example: If your DS0s on your CSU/DSUs are set up for 56Kbps, use 56 and if they are set up for
64Kbps DS0s, use 64.
PBXgateway System Administrator's Guide 219