NEC UNIVERGE SV8100 Features & Specifications Manual page 392

Issue 5.0
In this example, there are multiple T1 circuits and a BRI circuit. Since the T1 assigned as EXTERNAL
has higher priority than a BRI, the T1 EXTERNAL is the PLO synchronization source.
In this example, there is a PRI, multiple T1s, and a BRI. The PRI was the PLO synchronization source
until it went down. The BRI then becomes the PLO synchronization source because when a PRI is in the
system, T1s cannot be assigned as EXTERNAL, which are not in the PLO Synchronization Source
priority list.
If multiple BRIs exist and no PRI or T-1 EXTERNAL exists, the system chooses the first BRI that
synchronized with the carrier. In this example, the BRI in 04 synchronized with the carrier first and
became the PLO synchronization source.
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Figure 1-7 Digital Trunk Clocking Example 5
Figure 1-8 Digital Trunk Clocking Example 6
Figure 1-9 Digital Trunk Clocking Example 7
UNIVERGE SV8100
Digital Trunk Clocking