Chapter 2 Alarm Troubleshooting

2.7.141 LOM

2.7.141 LOM

Default Severity: Critical (CR), Service-Affecting (SA) for STSMON and STSTRM; Major (MJ) for VT-TERM

SONET Logical Objects: STSMON, STSTRM, VT-TERM

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.

Note Optical cards do not recognize the LOM. The system redirects the LOM alarm to the incoming side so 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.

2.7.142 LOP-P

Default Severity: Critical (CR), Service-Affecting (SA)

SONET Logical Objects: STSMON, STSTRM

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.

Step 3 If you have been monitoring the circuit with optical test equipment, a mismatch between the provisioned 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.

Caution Always use the supplied electrostatic discharge wristband when working with a powered ONS 15310-CL or ONS 15310-MA.

Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0

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Cisco Systems ONS 15310-MA, ONS 15310-CL manual 141 LOM, Lop-P, Clear the LOM Alarm, Clear the LOP-P Alarm
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ONS 15310-CL, ONS 15310-MA specifications

Cisco Systems has long been a leader in networking and telecommunications technology, and among its impressive lineup of products, the Cisco ONS 15310 series stands out as an essential solution for optical networking. This series includes models such as the ONS 15310-MA, ONS 15310-CL, and ONS 15310-CA, each designed to meet the diverse needs of service providers and enterprises seeking to enhance their optical transport networks.

The Cisco ONS 15310-MA is an advanced multi-service platform designed for metropolitan area networks. It facilitates the seamless transport of data, voice, and video over optical networks. One of its main features is its ability to support a variety of interfaces, including Ethernet, SONET/SDH, and Wavelength Division Multiplexing (WDM), allowing users to integrate multiple services into a single platform. Additionally, the ONS 15310-MA supports advanced traffic management and Quality of Service (QoS) features to prioritize critical applications and ensure consistent performance.

The ONS 15310-CL variant is tailored for more specific applications, providing enhanced capabilities aimed at delivering carrier-grade services. It features a robust architecture that accommodates high-capacity traffic without compromising reliability. This model emphasizes low power consumption and a compact design, making it suitable for deployment in space-constrained environments. The ONS 15310-CL also supports a wide range of optical interfaces, making it highly flexible for various network configurations.

In terms of technologies, the Cisco ONS 15310 series leverages Optical Transport Network (OTN) capabilities, providing high efficiency and greater bandwidth utilization. OTN technology enables efficient error correction and adds resilience to the network through its built-in protection mechanisms. Furthermore, the series supports seamless integration with existing IP/MPLS networks, creating a cohesive infrastructure as organizations evolve their networking requirements.

One of the defining characteristics of the ONS 15310 series is its focus on scalability. Network operators can start with a modest deployment and gradually expand capacity as demand grows. This adaptability is complemented by Cisco's comprehensive management and monitoring tools, providing operators with real-time insights into network performance and facilitating proactive management.

In conclusion, the Cisco ONS 15310-MA and ONS 15310-CL models represent sophisticated solutions for modern optical networks. With their versatile features, advanced technologies, and robust design, they empower service providers and enterprises to build resilient, high-capacity networks that meet the demands of today’s data-driven world.
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