Nortel Networks NN43001-301 manual Free run non-tracking mode, Reference clock errors

NT8D72 PRI2 29

Figure 6

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 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.)

In tracking mode, at any one time, there is one active clock controller which is tracking on one reference clock. If a clock-controller error is detected, the system switches to the back-up clock controller, without affecting which reference clock is being tracked.

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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