Specifications

1-4
Cisco ONS 15454 Troubleshooting and Maintenance Guide
November 2001
Chapter 1 Alarm Troubleshooting
1.3 Alarm Procedures
This section list alarms alphabetically and includes some conditions commonly encountered when
troubleshooting alarms. The severity, description and troubleshooting procedure accompany each alarm
and condition.
1.3.1 AIS
• Not Reported (NR)
The ONS 15454 detects an alarm indication signal (AIS) in the SONET overhead. This alarm is
secondary to another alarm occurring simultaneously in an upstream node. An incomplete circuit path
causes an AIS, for example, when the port on the reporting node is in-service but the OC-N port on a
node upstream on the circuit is not in-service. The upstream node often reports a loss of service or has
an out-of-service port. The AIS clears when you clear the primary alarm on the upstream node. However,
the primary alarm node may not report any alarms that indicate it is at fault.
Procedure: Clear the AIS Condition
Step 1 Check upstream nodes and equipment for alarms, especially for LOS and out-of-service ports.
Step 2 Clear the upstream alarms.
1.3.2 AIS-L
• Not Reported (NR)
The ONS 15454 detects an alarm indication signal (AIS) in the SONET overhead. This alarm is
secondary to another alarm occurring simultaneously in an upstream node. An incomplete circuit path
causes an AIS, for example, when the port on the reporting node is in-service but a node upstream on
the circuit does not have its OC-N port in-service. The upstream node often reports an LOS or has an
out-of-service port. The AIS-L clears when you clear the primary alarm on the upstream node. However,
the primary alarm node may not report any alarms that indicate it is at fault.
An AIS-L occurs at the line layer. The line layer refers to the segment between two SONET devices in
the circuit and is also known as a maintenance span. The line layer deals with SONET payload transport,
and its functions include multiplexing and synchronization.
Procedure: Clear the AIS-L Condition
Step 1 Check upstream nodes and equipment for alarms, especially for LOS and an out-of-service port.
Step 2 Clear the upstream alarms.