Nokia 4A0-265 Practice Exam Questions & Answers

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.Reference:Nokia Optical Diagnostics and Troubleshooting Course,OAM and Diagnostics Guide

The available output optical power range is the difference between the maximum gain and the minimum gain range of the ingress amplifier. According to the EPT Power Management Report, the maximum gain is 25.7 dB and the minimum gain range is 14 dB. Therefore, the available output optical power range is 25.7 - 14 = 11.7 dB. To convert this to a logarithmic scale, we use the formula 10^(x/10), where x is the value in dB. Therefore, the available output optical power range in logarithmic scale is 10^(11.7/10) - 10^(14/10) = 14.68 - 25.12 = -0.6 to 1.72 dB.Reference:Nokia Optical Diagnostics and Troubleshooting Course | Nokia,EPT Power Management Report | Nokia

The recommended order for the troubleshooting steps is A, as follows:

Retrieve the channel power trace.This step is useful to identify the affected channel and its power level, as well as to check if there are any fluctuations or anomalies in the power trace that could indicate a clock source issue1.

Determine the active clock reference source. This step is necessary to verify which clock source is currently used by the node, and if it matches the expected configuration.The clock source can be either a local oscillator (LO) or a phase-locked loop (PLL) that synchronizes with an external reference2.The active clock source can be determined by using the commandshow interface ot 1/1/lineout detail3.

Switch to alternate clock source (PF). This step is helpful to isolate the problem and confirm if the suspect PF is indeed causing the channel-related alarm.By switching to an alternate clock source, such as another PF or an external reference, the node can recover from the alarm if the original clock source was faulty4.

Replace the suspect PF. This step is the final solution to resolve the issue and restore the normal operation of the node.The suspect PF should be replaced with a new one that has the same specifications and configuration as the original one5.Reference:Nokia Optical Diagnostics and Troubleshooting Course | Nokia,Optical User Guide - Nokia,Alcatel-Lucent 1830 PSS-8 and PSS-16 Photonic Service Switch

A ''Power Adjustment Required'' alarm is raised when the optical power levels of an amplifier are out of the expected range and need to be adjusted. To manually adjust the related amplifier optical power levels, the commandconfig powermgmt ingress 1/10 adjustshould be entered. This command will initiate a power adjustment process for the ingress amplifier in slot 1/10, which is the input port for the optical line signal. The command will also display the status and results of the power adjustment, such as success, failure, or conditional success. The other commands are incorrect because they either do not initiate a power adjustment process or have invalid syntax.Reference:Nokia Optical Diagnostics and Troubleshooting Course,OAM and Diagnostics Guide

The commandshow interface 1/8/UNEIN detailis used to retrieve the total optical power detected at the ingress interface of a Raman amplifier. This command displays detailed information about the UNEIN interface, which is the unidirectional east input interface of the Raman amplifier.The total optical power detected at the UNEIN interface is shown asInput Power (dBm)in the output of this command1.Reference:Nokia Optical Diagnostics and Troubleshooting Course | Nokia

The alarm masking mechanism is a feature of the 1830 PSS that prevents unnecessary alarms from being displayed on the GUI or forwarded to an external NMS when they are caused by a known fault or maintenance activity. For example, if an optical link is down due to a fiber cut, there is no need to show alarms for all the downstream interfaces that are affected by the link failure. The alarm masking mechanism hides these alarms until the root cause is resolved, and then shows them again if they persist. The alarm masking mechanism preserves the events' original time stamps when it masks/shows alarms, so that when an alarm is not masked anymore, the user can see the original date and time associated with the issue. This helps to identify and troubleshoot problems more accurately and efficiently.Reference:Optical User Guide - Nokia,Alcatel-Lucent 1830 PSS-8 and PSS-16 Photonic Service Switch

The commandshow wavekey wtmonitor 1/6/LINE summarydisplays a list of all channels detected against the selected interface (in and out); it shows if a Wave Keys pair is expected, if a Wave Keys pair is received, and if the received Wave Keys pair is unexpected. A Wave Keys pair is a pair of unique identifiers that are transmitted along with an optical channel to provide channel identification and monitoring functions. The command can be used to verify the presence and correctness of the Wave Keys pairs on an interface and to detect any mismatch or misconfiguration. The other options are incorrect because they either describe a different command or provide incorrect information.Reference:Nokia Optical Diagnostics and Troubleshooting Course,OAM and Diagnostics Guide