NEC Electra Elite IPK II System User Manual page 323

Electra Elite IPK II
Digital Trunk Clocking Examples:
If multiple PRIs exist, the first one that synchronized with the carrier is chosen. In this example, the PRI
in S1 was the first to synchronize with the carrier; therefore, it is the PLO synchronization source.
If multiple PRIs exist and the one being used for the source goes down, the system begins to count
forward in slot numbers looking for the next available PRI. In this example, the PRI in S1 went down, so
the system now begins looking forward in slot numbers for the next PRI to use as the clock source.
Digital Trunk Clocking
Figure 2-3 Digital Trunk Clocking Example 1
Figure 2-4 Digital Trunk Clocking Example 2
Document Revision 4C
2 - 299