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Cisco ONS 15310-MA SDH Troubleshooting Guide, Release 9.0
78-18663-01
Chapter 2 Alarm Troubleshooting
Trouble Notifications
Facility (port) alarms also follow a hierarchy; lower-ranking alarms are closed by higher-ranking alarms.
The facility alarm hierarchy used in the systems is shown in Table 2-10.
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 (MS-AIS), path
(AU-AIS, etc.) or VC (TU-AIS, etc.). The full hierarchy for near-end failures is shown in Table 2-11.
This table is taken from Telcordia GR-253-CORE.
Table 2-10 Facility Alarm Hierarchy
Priority Condition Type
Highest LOS
—LOF
—MS-AIS
—MS-EXC
—SD-L
—MS-RFI
—RS-TIM
—AU-AIS
—AU-LOP
—HP-EXC
—HP-DEG
—HP-UNEQ
—HP-TIM
Lowest LP-PLM
Table 2-11 Near-End Alarm Hierarchy
Priority Condition Type
Highest LOS
—LOF
—MS-AIS
—AU-AIS
1
—AU-LOP
2
—HP-UNEQ
—HP-TIM
— LP-PLM
—TU-AIS
1
—TU-LOP
2
—LP-UNEQ