AT&T MERLIN LEGEND Release 3.1 System Planning Manual page 97

Selecting Line/Trunk Options
9. If assigning backup synchronization:
a. In the box that describes the 100D module providing secondary
synchronization, check Secondary.
b. In the box that describes the 100D module providing tertiary back up,
check Tertiary.
10. Under the Source subheading in each box, do one of the following:
To retain the factory setting, check Loop (that is, the system uses the
clock of the far-end connection).
To change the setting, check Local (that is, the clock is free-running).
NOTE:
The MERLIN LEGEND system must be set to Loop if the clock Source is
coming from the network. The Local setting is generated from the
MERLIN LEGEND system and must be used whenever connecting two
MERLIN LEGEND systems or a MERLIN LEGEND system and a
DEFINITY system (Tie trunk). In a Tie trunk configuration, one system
MUST have the clock Source set to Local and the other MUST be set to
Loop.
11. Under the Activation subheading in each box, do one of the following:
If loop clock synchronization is taking place, check Active (factory
setting).
If the clock is free-running, check Not Active.
NOTE:
Normally, the primary synchronization source is set to Active and other
modules are set to "Not Active."
12. If incoming ground-start or loop-start trunks are to be emulated, then
record the CSU setting under the Channel Service Unit heading by doing
one of the following :
To retain the factory setting, check Foreign Exchange.
To change the factory setting, check Special Access.
To set up T1 channels for T1 Switched 56 service, continue with the next
section. To set up T1 Switched 56 service on T1-Tie trunks, proceed to the
section entitled "Tie Trunks." To set up a 100D module for PRI service, proceed
to the section entitled "PRI Service."
3–25
Lines/Trunks