Troubleshooting the Physical Layer of DWDM Systems: A Case Study

摘要

This article will discuss troubleshooting methods to isolate those defects by examining optical timedomain reflectometer readings and interpreting the results. Individual circuits have not yielded errors specifically for this activity. Instead, we are preventing instability by proactively identifying DWDM systems' that have the potential to mask circuit issues. Software pumps on the network element are failing to boost the wavelengths into acceptable ranges. While this has not affected traffic at this point, the DWDM is not running at its optimal levcL To isolate and correct defects in the common fiber, the methodology chosen will be installing a new fiber patch system from the DWDM network element to the outside plant fiber. Each fiber patch will be prequalified for optimal use by taking OTDR readings and verifying optimization prior to install Once each segment is installed and capped, a maintenance window will be scheduled for off-peak hours to minimize impact to customer circuits. Traffic will be rolled to the new fiber, and the existing fiber will be investigated using OTDR readings and a video fiberscope. By testing the fiber intrusively, engineers can determine if the span loss is within acceptable limits and is not contributing to possible instability.