Table 3-5. Line Compensation Settings; Clock Synchronization - AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual

Lines and Trunks
premises and is used to connect the system to DS1 network facilities. The CSU
has three functions:
It terminates an outside DS1 facility on the 100D module.
It ensures that the signals entering the public network comply with the
requirements of the DS1 facility as specified by the FCC.
It includes maintenance, diagnostic, and testing capabilities.
Line Compensation
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 3-5.

Table 3-5. Line Compensation Settings

NOTE:
Cable length in Table 3-5 is the distance between the 100D module and the
CSU. If no CSU is used, the distance between 100D modules is twice these
numbers.

Clock Synchronization

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 time-division multiplexing (TDM) bus must be
identified during system programming.
DS1 Facilities
3-20
dB Loss
Setting
1 0.6
1.2
2
3 1.8
4 2.4
5 3.0
Cable Length
(22-Gauge Wire)
0—133
133—266
266—399
399—533
533—655