MCK pbxgateway Administrator's Manual page 35

Product Overview
Voice The PBXgateway provides a choice of voice
Compression compression algorithms to allow up to 12 phones to be
Vs. Bandwidth
extended over T1, Fractional T1, or ISDN lines.
The compression algorithm selected determines the
bandwidth required.
T1: A digital transmission link at speeds of 1.544
million bits per second (or Twenty–four DS0s).
DS0: The worldwide standard speed for digitized voice
conversation at 64,000 bits per second.
ISDN: A digital transmission link consisting of two
"B" channels (bearer) for voice and one "D" channel
(data). Each "B" channel transmits voice signals at
64,000 bits per second.
The following are user selectable voice compression
methods supported by the PBXgateway to
accommodate the available bandwidth:
G.729A (8 Kbps)
ADPCM 24 (24 Kbps)
ADPCM 32 (32 Kbps)
G.711 (64 Kbps)
Note: These numbers indicate the bandwidth required
per phone, not including overhead.
References:
"
"
Bandwidth Requirements, see Appendix B
Setting the Voice Compression, see Setting the
Voice Compression Method in Chapter 4.
Issue 2.1 December 1999
1-9