AC Alternating Current
ACD Automatic Call Distribution
ADM Add/Drop Multiplexer
ADMCP Adaptive Differential Pulse Code Modulator
AMI Alternate Mark Inversion
ARS Automatic Route Selection
BH Busy Hour
BOC Bell Operating Company
bps Bits Per Second
BRI Basic Rate Interface
CO Central Office
Codec Coder/Decoder
CPE Customer Premises Equipment
CRC Cyclic Redundancy Checking
CSU Channel Service Unit