Chapter 2 Alarm Troubleshooting

Alarm Procedures

2.6.107 LOF (OC-N)

Critical (CR), Service Affecting (SA)

The OC-N LOF alarm occurs when a port on the reporting OC-N card has an LOF condition. LOF indicates that the receiving ONS 15327 has lost frame delineation in the incoming data. LOF occurs when the SONET overhead loses a valid framing pattern for 3 milliseconds. Receiving two consecutive valid A1/A2 framing patterns clears the alarm.

LOF on an OC-N card is sometimes an indication that the OC-N card reporting the alarm expects a specific line rate and the input line rate source does not match the input line rate of the optical receiver.

Warning Invisible laser radiation might be emitted from the end of the unterminated fiber cable or connector. Do not stare into the beam directly with optical instruments. Viewing the laser output with certain optical instruments (for example, eye loupes, magnifiers, and microscopes) within a distance of 100

mmmight pose an eye hazard. Use of controls or adjustments or performance of procedures other than those specified might result in hazardous radiation exposure.

Caution Always use the supplied electrostatic discharge wristband when working with a powered ONS 15327. Plug the wristband cable into the ESD jack located between the top high-speed and XTC slots.

Procedure: Clear the LOF (OC-N) Alarm

Step 1 Verify cabling continuity to the port reporting the alarm.

Step 2 If cabling continuity is correct, clean the fiber connectors according to site practice. If no site practice exists, complete the procedure in the Cisco ONS 15327 Procedure Guide.

Step 3 If the alarm does not clear, see the “Network Troubleshooting Tests” section on page 1-2to isolate the fault causing the LOF alarm.

Step 4 If the alarm does not clear, or if you need assistance conducting network troubleshooting tests, call TAC to report a service-affecting problem (1-800-553-2447).

2.6.108 LOP-P

Critical (CR), Service Affecting (SA)

A Loss of Pointer Path (LOP-P) 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.

Cisco ONS 15327 Troubleshooting Guide, R3.4

2-80

March 2004

 

 

Page 186
Image 186
Cisco Systems ONS 15327 manual Lof Oc-N, Lop-P, Procedure Clear the LOF OC-N Alarm

ONS 15327 specifications

Cisco Systems ONS 15327 is a high-performance optical networking solution tailored for service providers and enterprises looking to enhance their optical communication infrastructure. This versatile platform is recognized for its robust performance, scalability, and flexibility, making it suitable for a wide array of applications ranging from broadband access to metropolitan area networking.

One of the standout features of the ONS 15327 is its ability to handle multiple data types over a single platform. It supports a rich array of protocols, including Ethernet and SONET/SDH, allowing service providers to deliver a diverse portfolio of services to their customers. This multiservice capability simplifies the network architecture, reducing operational complexity and costs.

The ONS 15327 is designed with a modular architecture, which enables operators to customize and scale their network as demand grows. It supports a variety of card options for different media types, wavelengths, and capacity requirements. This modularity not only facilitates straightforward upgrades but also allows for efficient network management.

In terms of technology, the ONS 15327 leverages dense wavelength division multiplexing (DWDM) capabilities to maximize the utilization of available fiber bandwidth. This allows for an impressive increase in transmission capacity without the need for additional fiber installations, making it a cost-effective solution for expanding networks.

Another significant characteristic of the Cisco ONS 15327 is its advanced performance monitoring and management features. Built-in diagnostic tools provide real-time visibility into network performance, enabling prompt identification and troubleshooting of potential issues. This proactive approach to network management enhances service reliability and customer satisfaction.

Security is also paramount in the ONS 15327. The platform integrates various security features and protocols to protect the data traversing the network, ensuring compliance with industry standards and safeguarding sensitive information.

Furthermore, the equipment is designed for easy integration into existing infrastructures. Its compatibility with Cisco’s broader networking solutions allows for seamless interconnection with routers, switches, and other devices, facilitating comprehensive network solutions.

In conclusion, Cisco Systems ONS 15327 stands out as a powerful optical networking platform that combines versatility, scalability, and advanced management features. Its ability to support various protocols and harness optical technologies makes it an essential tool for organizations aiming to optimize their telecommunications infrastructure while minimizing costs and complexity.