Lucent Technologies MERLIN LEGEND Release 6.1 Maintenance And Troubleshooting Manual page 464

MERLIN LEGEND Communications System Release 6.1
Maintenance and Troubleshooting 555-661-140
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circuit-switched
data call
class of restriction
clear data channel
clock
synchronization
CMS
CO
Sum of ones in a sequence of ones and zeros used to
detect or correct errors in data transmission.
Data call made through an exclusively established and
maintained connection between data stations .
See COR .
Clear data channels (also called unrestricted data
channels) allow the transmission of occurrences of more
than seven contiguous zero bits. If a clear data channel is
requested and only restricted channels are available, the
call will be rejected. See also restricted data channel.
When digital signals are transmitted over a
communications link, the receiving end must be
synchronized with the transmitting end to receive the
digital signals without errors using clock synchronization.
A system synchronizes itself by extracting a timing signal
from an incoming digital stream. All the digital facilities in
a private network operate from a single common clock,
preferably a port connected to a digital PSTN facility on a
hub system or a system that connects two private network
systems. In this case, all digital facilities specify a loop
clock source. One system in a private network may be
specified as a local clock source when no functioning
digital facility in the private network is connected to the
PSTN. All other digital facilities then use this clock and
specify their clock sources as loop. Primary, secondary,
and tertiary clock sources are specified to allow backup
synchronization in the event that the primary source is
out of service.
(Call Management System) DOS-based application that
simulates the actions of a system operator by answering
and distributing calls. Also produces reports for call
analysis.
(central office) Location of telephone switching equipment
that provides local telephone service and access to toll
facilities for long-distance calling.
Issue 1
August 1998
Page GL-8