Span Drift Alarm; Span Phase Transient Event - Symmetricom TimeSource 2700 Manual

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Span Drift Alarm

Span drift event data is processed through a leaky-bucket alarm
manager, to control escalation to an event, or directly to a minor
alarm. Since occasional drift events are typical, the leaky bucket is
set to ignore isolated pointer and network rearrangement events.
The nominal time to escalate to an alarm is 4 minutes, and the
maximum time to retire the alarm is 2.5 minutes.
Maintenance action required - Occasional span drift alarm activity
may occur as a result of network maintenance. Persistent drift
alarm activity is not normal. Check the BTMONitor Alarm Log
screen, and if there are multiple events per day, the span line
input should be considered suspect. Timing on the incoming span
line is not within specification. Troubleshoot the source of the
timing for the incoming span line, or contact the span line service
provider.

Span Phase Transient Event

The phase event category is used to detect "fast" phase transient
events. A fast event is usually related to a timing transient in the
previous network element, as opposed to a slower event played out
through upstream intermediate clocks. In general, all phase
events will produce drift events. A phase event is observed over a
250 ms interval after removing network jitter. The default
threshold for a span phase transient event is greater than 250 ns.
Maintenance action required - None.
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Troubleshooting
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