Nortel Networks NN43001-301 manual Free run non-tracking mode

NT5D12 Dual-port DTI/PRI 71

As shown in Figure 30 "Clock Controller primary and secondary tracking" (page 71), a system with dual CPUs can have two clock controllers (CC-0 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:

•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.

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.)

Nortel Communication Server 1000

ISDN Primary Rate Interface Installation and Commissioning

NN43001-301 02.03 Standard

Release 5.5 7 December 2007

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