Alcatel-Lucent 1643 AMS Operation Manual page 49

Alarm messages
2 Mbit/s Frame slip/skip count threshold crossing 15-min
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Alarm identifier
Information
Alarm category
ASAP
Alarm severity
(default setting)
Reporting state
(default setting)
Local indications
Cause
Actions
Note(s)
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365-312-803R7.2
Issue 4, May 2007
FSCcTHR15
The configurable 15-minuteframe slip/skip count (FSC) threshold has been
exceeded, indicating that too many frame-slip buffer overflow or underflow
events occurred during a 15-minutemonitoring period.
Quality of service (performance monitoring)
pdhPath
Information
Not Reported
–
A frame slip/skip event indicates a synchronisation difference between the SDH
clock of the netwerk element that performs the re-timing and the network
element that generated the E1 (2 Mbit/s) signal, usually a voice switch or 64-
kbit/s level cross-connect.
Check the synchronisation trails to both the 1643 AM and 1643 AMS and the
network element that generated the E1 (2 Mbit/s) signal.
These two network elements should have their respective clocks traced back to
the same synchronization source when the 1643 AM and 1643 AMS system is
operated in the re-timed mode.
•
The default frame slip/skip count (FSC) thresholds for 15-minutemonitoring
periods are 2 (TR threshold) and 1 (RTR threshold), respectively.
•
Slipping or skipping of 2 Mbit/s frames is only possible when the E1 port
is configured to operate in the re-timing mode.
In this case a slip/skip event indicates a synchronization difference between
the SDH clock of the 1643 AM and 1643 AMS network element that
performs the re-timing and the network element that generated the E1 signal.
Re-timing should only be applied when these two network elements have
their respective clocks traced back to the same synchronization source,
otherwise a continuous stream of slips or skips will occur at the re-timing
point.
Alcatel-Lucent - Proprietary
See notice on first page
1-29