Line Compensation Settings - AT&T MERLIN LEGEND System Reference Manual

Functional Description
Line Compensation
Clock Synchronization
Line compensation adjusts for the amount of cable loss in decibels (dBs), based
on the length of cable between the 100D module and the CSU or other far-end
connection point. The factory setting is a value of 1, which allows a maximum
loss of 0.6 dB. The other possible settings are shown in Table 4-3.
Table 4-3

Line Compensation Settings

Clock synchronization is an arrangement where digital facilities operate from a
common clock. Whenever 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.
The system synchronizes itself to the network by extracting the timing signal
from the incoming digital stream. If the system has more than one 100D module,
the module that provides the primary synchronization for the other 100D
modules and for the TDM bus must be identified during system programming.
The factory setting is the first 100D module in the carrier. This can be changed
to the second or third module.
Backup synchronization in the event of a maintenance failure can be provided
by programming the second and third installed modules as secondary and
tertiary synchronization.
In addition, the source of synchronization can be factory set to "loop clock
reference source" (the clock is synchronized to the external endpoint—the
factory setting) or set to "local clock reference source" (the clock is free
running). This setting must be made for the primary, secondary, and tertiary
synchronization modules.
DS1 Facilities 4-31