Nortel 1000 Installation And Commissioning Manual page 71

As shown in
(page
and CC-1). One clock controller acts as a back-up to the other. Lock the
clock controllers to the reference clock.
Figure 30
Clock Controller primary and secondary tracking
Free run (non-tracking) mode
The clock synchronization of the system can operate in free-run mode if:
•
•
•
Reference clock errors
The system software checks at intervals of 1 to 15 minutes to see if a clock
controller or reference-clock error has occurred. (The interval of this check
can be configured in LD 73.)
Copyright © 2003-2007, Nortel Networks
.
Figure 30 "Clock Controller primary and secondary tracking"
71), a system with dual CPUs can have two clock controllers (CC-0
no loop is defined as the primary or secondary clock reference,
the primary and secondary references are disabled, or
the primary and secondary references are in local (near end) alarm.
Nortel Communication Server 1000
ISDN Primary Rate Interface Installation and Commissioning
NN43001-301 02.03 Standard
Release 5.5 7 December 2007
NT5D12 Dual-port DTI/PRI 71