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Cisco ONS 15454 DWDM Reference Manual, R8.5
78-18343-02
Chapter 16 Alarm and TCA Monitoring and Management
16.9 Threshold Crossing Alert Suppression
16.8.2.1 Ethernet Communication Alarms
The Ethernet interface card (MS-ISC) that is required for multishelf configurations does not raise
traditional Ethernet alarms, such as CARLOSS, that apply to transponder (TXP) or muxponder (MXP)
client ports. Instead, MS-ISC card alarms are raised on the shelf as EQPT alarms. These alarms include
Duplicate Shelf ID (DUP-SHELF-ID) and Shelf Communication Failure (SHELF-COMM-FAIL).
16.8.2.2 Multishelf Correlated Alarms
ITU-T G.798-based alarm correlation simplifies alarm reporting for DWDM channels. Communication
failures including Loss of Signal (LOS), Loss of Signal Payload (LOS-P), and Optical Power Receive
Fail-Loss of Light (OPWR-LFAIL) generate multiple conditions at each affected node and channel.
Correlation simplifies troubleshooting because a single alarm is reported for each root cause. (The
original alarms retain their severity in the Conditions window.)
The Payload Missing Indication (PMI) condition is raised at the far end to correlate optical multiplex
section (OMS) and optical transmission section (OTS) communication failures. A single PMI condition
is sent when every channel on the aggregated port is lost, that is, when there are no pass-through channels
or active added channels in service. If there are added channels on the node, the Forward Defect
Indication (FDI) condition is raised at the near end to indicate there are no pass-through optical channels
(OCH) in service.
16.9 Threshold Crossing Alert Suppression
This section describes threshold crosssing alert (TCA) suppression on TXP and MXP cards when they
are installed in a DWDM node.
16.9.1 Overview
Threshold default settings define the default cumulative values (thresholds) beyond which a TCA will
be raised. TCAs make it possible to monitor the network and detect errors early.
The following thresholds are monitored for TXP and MXP cards:
• Optical Thresholds
• ITU-T G.709 Thresholds
• SONET and SDH Thresholds
• FEC Thresholds
Threshold defaults are defined for near end and/or far end and at 15-minute or one-day intervals.
When LOS-P, LOS, or LOF alarms occur on the TXP./MXP cards, different TCAs are suppressed. Which
TCAs are suppressed by an alarm depends on how the trunk is configured (ITU-T G.709, SONET, or
SDH). The reason for suppressing the TCAs after the alarm occurs is to prevent a flood of TCAs after a
system failure.
TCA suppression does not extend to optical thresholds such as OPR (optical power received). Optical
threshold TCAs can effectively be suppressed by setting their thresholds to the maximum value.TCA
suppression also does not extend to client ports; it only applies to TXP and MXP trunk ports when they
are configured as ITU-T G.709, SONET, or SDH. TCA suppression does not extend to 10GE payloads.
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