Lom; Clear The Lom Alarm; Lop-P; Clear The Lop-P Alarm - Cisco ONS 15310-CL Troubleshooting Manual

1.7.141 LOM

1.7.141 LOM
The Optical Transport Unit (OTU) Loss of Multiframe is a VCAT member alarm. (VCAT member
circuits are independent circuits that are concatenated from different time slots into a higher-rate signal.)
The alarm applies to OCN ports when the Multi Frame Alignment Signal (MFAS) overhead field is
errored for more than five frames and persists for more than 3 milliseconds.
Optical cards do not recognize the LOM. The system redirects the LOM alarm to the incoming side so
Note
that any optical card can display this alarm as a TERM alarm.

Clear the LOM Alarm

To clear the alarm, log into the Technical Support Website at http://www.cisco.com/techsupport for more
information or call Cisco TAC (1 800 553-2447) in order to report a Service-Affecting (SA) problem.

1.7.142 LOP-P

A Loss of Pointer Path alarm indicates that the SONET path pointer in the overhead has been lost. LOP
occurs when valid H1/H2 pointer bytes are missing from the overhead. Receiving equipment monitors
the H1/H2 pointer bytes to locate the SONET payload. An LOP-P alarm occurs when eight, nine, or ten
consecutive frames do not have valid pointer values. The alarm clears when three consecutive valid
pointers are received.
The LOP-P alarm can occur when the received payload does not match the provisioned payload. The
alarm is caused by a circuit type mismatch on the concatenation facility. For example, if an STS-1 is sent
across a circuit provisioned for STS-3c, an LOP-P alarm occurs.

Clear the LOP-P Alarm

Step 1 In node view, click the Circuits tab and view the alarmed circuit.
Step 2 Verify the circuit size listed in the Size column. If the size is different from what is expected, such as an
STS3c instead of an STS1, this raises the alarm.
If you have been monitoring the circuit with optical test equipment, a mismatch between the provisioned
Step 3
circuit size and the size expected by the test set can cause this alarm. Ensure that the test set monitoring
is set up for the same size as the circuit provisioning.
For instructions to use the optical test set, consult the manufacturer.
Always use the supplied electrostatic discharge wristband when working with a powered ONS 15310-CL
Caution
or ONS 15310-MA.
Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
1-92
Default Severity: Critical (CR), Service-Affecting (SA) for STSMON and STSTRM; Major (MJ)
for VT-TERM
SONET Logical Objects: STSMON, STSTRM, VT-TERM
Default Severity: Critical (CR), Service-Affecting (SA)
SONET Logical Objects: STSMON, STSTRM
Chapter 1 Alarm Troubleshooting
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