Zhone Technologies, Inc. | IMACS Product Book, Version 4 |
The sum of the compression rates for the engine pair must equal 64Kbps. A 32Kbps circuit can only be paired with a 32Kbps circuit. A 40Kbps circuit can only be paired with a 24Kbps circuit and
Modem support up to 4.8Kbps, and V.32bis to 9.6Kbps is supported in 32Kbps channels. Modem speeds up to 12Kbps, and V.32bis speeds up to 14.4Kbps is supported in 40Kbps channels. Modem data is not supported in 24Kbps channels.
The ADPCM card supports Transition Signaling as defined by ANSI
The ADPCM card can be used in a variety of applications to reduce the number of transmission lines for efficient transport of voice traffic. It can be used in:
•
•Automatic Call Distribution application
•Efficient wireless base station/hub application
PBX-to-PBX Trunk Application
Figure 21a shows the IMACS with an ADPCM server is used to compress two T1 or E1 PBX-to-PBX trunks into a single trunk. The voice from each PBX is connected via a digital T1 or E1 connection to the IMACS. The voice channels are routed to the ADPCM server, where each voice channel is compressed to 32 Kbps. The compressed voice is routed to the outbound T1/E1 link to the other IMACS unit, where it is decompressed and placed back into two T1 or E1 trunks to the remote PBX. PBX-to-PBX trunk lines can be compressed 2:1 to reduce leased line charges. The application is also valid for analog PBXs and key systems.
T1/E1 
IMACS |
PBX
T1/E1 carrier |
|
Network | IMACS |
T1/E1
PBX
Figure 21a - IMACS Using ADPCM for PBX to PBX Application
March 2001 | Page 67 |