Instruction manual

Glossary
Centrex
channel
channel service
unit
checksum
circuit-switched
data call
class of
restriction
clock
synchronization
CMS
coaxial cable
codec
common
channel
signaling
communications
system
control unit
A set of communications system features to which a user
can subscribe on telephone trunks from the local telephone
company.
A telecommunications transmission path for voice and/or
data.
See CSU.
The sum of ones in a sequence of ones and zeroes to
detect or correct errors in data transmission.
A data call made via a connection exclusively established
and maintained between data stations for the duration of
the data call.
See COR.
The operation of digital facilities from a common clock.
(Call Management System) A DOS-based application that
simulates the actions of a system operator by answering
and distributing calls. CMS also produces management
reports for call analysis.
A cable consisting of one conductor, usually a small copper
tube or wire, within and insulated from another conductor of
large diameter, usually copper tubing or copper braid.
(Coder-decoder) A device used to convert analog signals
such as speech, music, or television to digital form for
transmission over a digital medium and back to the original
analog form.
See CCS.
The software-controlled processor complex that interprets
dialing pulses, tones, and or keyboard characters and
makes the proper interconnections both inside and outside
the system. The communications system consists of a
digital computer, software, a storage device, and carriers
with special hardware to perform the actual connections. A
communications system provides voice and/or data
communications services, including access to public and
private networks, for telephones and data terminals on a
customer’s premises.
The processor, power supply, modules, carriers, and
housing of the communications system.
GL-6 Glossary