4A0-265 Practice Exam Questions with Answers Nokia Optical Diagnostics and Troubleshooting Exam Certification

 The available output optical power range is the same as in question 5, since the EPT Power Management Report refers to the same ingress amplifier with the same settings and parameters. Therefore, the answer is also A, -0.6 to 1.72 dB. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, EPT Power Management Report | Nokia

On a bidirectional optical amplifier configuration, the Wavelength Tracker detection points are the LINE and SIG interfaces. The Wavelength Tracker is a feature that monitors the wavelength of each channel on the optical amplifier and provides feedback to the control system. The Wavelength Tracker can detect wavelength drifts, channel failures, or channel additions or removals on both directions of the optical amplifier. The LINE interface is the input/output port for the optical line signal, while the SIG interface is the input/output port for the optical signal from/to the transponder. The other options are incorrect because the LINEOUT and SIGOUT interfaces are not Wavelength Tracker detection points, and an optical amplifier has Wavelength Tracker detection points. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

The exhibit shows a diagram of an OT module with a client port and a DWDM port. The client port is looped back to itself with an OEO (Optical-Electrical-Optical) device. This means that the signal received by the client port is converted to an electrical signal, then back to an optical signal, and then transmitted back to the same port. This type of loopback is called a client portterminal loopback. It is used to test the functionality of the client port without involving the DWDM port or any other network element4. A client port facility loopback would involve looping back the signal from the DWDM port to the client port. A line port facility loopback would involve looping back the signal from another OT module or network element to the DWDM port. A line port terminal loopback would involve looping back the signal from the DWDM port to itself5. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Loopback - Wikipedia

The command show xc 1 displays a list of cross-connections, including A-end, Z-end, frequency, ID number, OCH trail name, and administrative/operational states. A cross-connection is a logical connection between two ports on an optical network element that allows the transmission of an optical signal from one port to another. The command can be used to view the configuration and status of the cross-connections on a node or a network. The other options are incorrect because they either describe a different command or provide incorrect information. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

The statement that best describes the Forward Error Correction (FEC) technique is C. FEC is a technique used in digital communication to improve the accuracy and reliability of data transmission. By adding redundant information to the transmitted data, FEC enables the receiver to detect and correct errors without retransmission or other error correction techniques11. FEC is effective only above a specified OSNR threshold, which is the minimum optical signal-to-noise ratio required for error-free transmission with FEC enabled. If the OSNR falls below this threshold, FEC cannot correct all errors and data quality degrades significantly. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical User Guide - Nokia, Forward Error Correction (FEC) - Online Tutorials Library

The exhibit shows a graph of optical power levels measured at different interfaces throughout the optical path of a single wavelength. The different colored green columns indicate the optical power levels at different points along the optical path, such as the transmitter, the receiver, and the amplifiers. The graph also shows the expected power levels and the allowed deviation range for each point. The graph can be used to monitor the performance and quality of the optical signal and to identify any potential issues or anomalies. The other options are incorrect because they either describe a different type of graph or do not match the exhibit. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

When troubleshooting possible generic fiber cuts, the recommended first step is to review alarms at nodes where power loss occurs. This can help identify the location and extent of the fiber cut and the affected services. The next recommended step is to perform network power traces to attempt to determine the point of power loss. Network power traces are graphical representations of the optical power levels along a span or a path. They can be used to compare the measured power levels with the expected power levels and to pinpoint any significant deviations or drops that indicate a fiber cut. The other options are incorrect because they either do not help locate the fiber cut or are not as effective as network power traces. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide