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Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
Chapter 2 Alarm Troubleshooting
2.5.4 Alarm Hierarchy
Near-end failures and far-end failures follow different hierarchies. Near-end failures stand according to
whether they are for the entire signal (LOS, loss of frame alignment [LOF]), facility (AIS-L), path
(AIS-P, etc.) or VT (AIS-V, etc.). The full hierarchy for near-end failures is shown in Table 2-11. This
table is taken from Telcordia GR-253-CORE.
The far-end failure alarm hierarchy is shown in Table 2-12, as given in Telcordia GR-253-CORE.
—SD-P
— UNEQ-P
—TIM-P
Lowest PLM-P
Table 2-10 Facility Alarm Hierarchy (continued)
Priority Condition Type
Table 2-11 Near-End Alarm Hierarchy
Priority Condition Type
Highest LOS
—LOF
—AIS-L
—AIS-P
1
1. Although it is not defined as a defect or failure, all-ones STS pointer relay is also
higher priority than LOP-P. Similarly, all-ones VT pointer relay is higher priority
than LOP-V.
—LOP-P
2
2. LOP-P is also higher priority than the far-end failure RFI-P, which does not affect
the detection of any near-end failures. Similarly, LOP-V is higher priority than
RFI-V.
— UNEQ-P
—TIM-P
—PLM-P
—AIS-V
1
—LOP-V
2
— UNEQ-V
—PLM-V
Lowest DS-N AIS (if reported for
outgoing DS-N signals)
Table 2-12 Far-End Alarm Hierarchy
Priority Condition Type
Highest RFI-L
—RFI-P
Lowest RFI-V