AT&T MERLIN LEGEND Installation & Maintenance Manual page 691

Glossary
circuit-switched data call
A data call made via a
connection exclusively
established and maintained
between data stations for the
duration of the data call.
clock synchronization
The operation of digital
facilities from a common
clock.
coaxial cable
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.
codec (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.
CO line/trunk jack
A jack that connects an
outside line/trunk to the
communications system
control unit.
GL-6 Glossary
common-channel signaling
(CCS)
Signaling in which one
channel of a group of
channels carries signaling
information for each of the
remaining channels,
permitting each of the
remaining channels to be
used to nearly full capacity. In
the system's DS1 module,
channel 24 can be
designated as the signaling
channel for channels 1–23 by
selecting "common channel"
for emulated service when
programming the system.
CCS must be used for lSDN-
PRI service.