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The Customer Release Notes (CRNs) document collects documented solved known issues, new issues discovered after the product software has been released, as well as software upgrade procedures and firmware details. This document is useful for troubleshooting because it can help identify if a problem is related to a known issue or a software bug, and if there is a workaround or a solution available. The CRNs also provide information about the software compatibility and interoperability of different Nokia products and platforms. The other options are incorrect because the EPTUG and the UPG do not contain information about known issues, and the CRNs do not provide instructions for automated provisioning, commissioning, and power balancing functions. References: Nokia Optical Diagnostics and Troubleshooting Course, Nokia Optical Diagnostics and Troubleshooting Exam

The command show wavekey wtmonitor 1/6/LINE summary displays 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. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

 A Threshold Crossing Alert (TCA) alarm is a type of alarm that indicates that a monitored parameter has crossed a predefined threshold. For example, a TCA alarm can be triggered when the optical power received at a port is too high or too low. The default severity level for a TCA alarm is warning, which means that it does not affect the service but may require attention. The other severity levels are critical, major, and minor, which indicate different degrees of impact and urgency of the alarms. The severity level of a TCA alarm can be changed by the user using the Nokia 1830 Engineering and Planning Tool (EPT) or the Nokia 1350 Optical Management System (OMS). References: Nokia Optical Diagnostics and Troubleshooting Course, Nokia 1830 PSS-32 and PSS-16 Photonic Service Switch Release 8.0 Alarms and Conditions Reference Guide

A “Loss of Signal” (LOS) alarm is a critical alarm that indicates that there is no or very bad signal at the physical interface. LOS alarm is also raised when the signal level drops below the threshold, at which a high bit error rate (BER) is predicted. LOS alarm can be caused by physical damage, power outage, or misconfiguration of the equipment. LOS alarm can affect the service availability and performance of the optical network. Therefore, it is typically assigned a critical severity level, which means that it requires immediate attention and resolution2. Other severity levels are major, minor, and warning, which indicate different degrees of impact and urgency of the alarms. References: Troubleshooting Guide for Cisco NCS 1002, T1: A Survival Guide, M-series SONET/SDH alarms and troubleshooting tips

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

A power adjustment has succeeded conditionally because of gain settings set to higher levels than expected by design. This means that the optical power levels of the amplifier have been adjusted within the acceptable range, but the gain values are higher than the design values. This can cause a performance degradation or instability of the optical signal. The alarm that will raise in this case is “Amplifier Gain Tilt Adjustments Suspended” (PWRTILTSUSP). This alarm indicates that the gain tilt adjustments, which are used to compensate for the wavelength-dependent loss of the optical signal, have been suspended due to high gain values. The alarm also suggests lowering the gain values manually or using the EPT tool. The other alarms are incorrect because they either indicate a different type of power adjustment issue or do not exist. References: 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 1.72dB. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, EPT Power Management Report | Nokia

The statement that WT uses a unique identifier based on a pair of numbers encoded by Optical Transponders (OTs) into each service wavelength direction is TRUE. WT is a feature of the 1830 PSS that allows for automatic identification and tracking of wavelengths across different network elements and domains. WT uses Wave Keys, which are unique identifiers composed of two numbers: a Wave Key ID and a Wave Key Code. The Wave Key ID identifies the OT that generates the wavelength, while the Wave Key Code identifies the wavelength itself within a given OT6. The Wave Keys are encoded by OTs into each service wavelength direction using phase modulation, and can be decoded by other OTs or amplifiers that have WT capability. WT enables various applications and benefits, such as simplified commissioning, automated wavelength routing, enhanced fault localization, and improved network security. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical User Guide - Nokia, Alcatel-Lucent 1830 PSS-8 and PSS-16 Photonic Service Switch

1-Day PMs are one of the types of PM data that can be retrieved from an optical network element. 1-Day PMs show measurements collected over the preceding 24 hours, with each hour being a bin. Up to 8 bins are available for data storing, which means that only the most recent 8 hours of data can be accessed. The other types of PM data are 15-Minute PMs, which show measurements collected over the preceding 15 minutes, with each minute being a bin, and Total PMs, which show measurements collected since the last reset of the PM counters. References: Nokia Optical Diagnostics and Troubleshooting Course, Nokia 1830 PSS-32 and PSS-16 Photonic Service Switch Release 8.0 Performance Monitoring Reference Guide

A single directional fiber cut is occurring between two amplifiers in unidirectional configuration with Raman pump. Multiple services are crossing the affected span. The node(s) that will report an Incoming Payload LOS alarm are both Node A and Node C. An Incoming Payload LOS alarm indicates that there is no or very low signal at the input port of a node. In the exhibit, Node A will report this alarm because it will not receive any signal from Node B due to the fiber cut. Node C will also report this alarm because it will not receive any signal from Node D due to the fiber cut. The Raman pump in Node A does not prevent this alarm, as it only amplifies the signal in the forward direction, not the backward direction. The other options are incorrect because they either ignore one of the nodes that will report the alarm or assume that the Raman pump has an effect on the backward direction. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide