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 The statement that an “Incoming SUPVY LOS” alarm is raised on the local node is NOT a characteristic of an Optical Supervisory Channel Loss of Signal (OSC LOS) issue, in case that no “LD Input LOS” alarms are raised against the involved amplifiers. An “Incoming SUPVY LOS” alarm indicates that the input signal of the Optical Supervisory Channel (OSC) is lost or below the threshold6. The OSC is a bidirectional channel that connects two adjacent nodes in a DWDM network and carries OAM information and other services7. An OSC LOS issue can occur due to a fiber cut, a defective or dirty OSC fiber, or a faulty OSC transmitter or receiver8. However, if there is no “LD Input LOS” alarm raised against the involved amplifiers, it means that there is no loss of signal on the line interface of the amplifier, which carries both service channels and OSC channels9. Therefore, an “Incoming SUPVY LOS” alarm on the local node is not related to an OSC LOS issue, but rather to an OSC configuration issue or a faulty OSC card10. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical User Guide - Nokia, Alcatel-Lucent 1830 PSS-8 and PSS-16 Photonic Service Switch

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 command show 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 replacedwith a new one that has the same specifications and configuration as the original one5. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical User Guide - Nokia, Alcatel-Lucent 1830 PSS-8 and PSS-16 Photonic Service Switch

In bidirectional configurations, where the same fiber is used to transmit signals in both directions, power adjustments can be performed at both ingress and egress amplifiers. The ingress power adjustments are performed against the ingress amplifiers, which boost the incoming signals from the opposite direction. The egress power adjustments are performed against the egress amplifiers, which boost the outgoing signals from the same direction2. Therefore, the statement A is correct. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical amplifiers, explained by RP; optical amplification

The exhibit shows a diagram of a network of nodes and edges, where a single directional fiber cut is occurring between two amplifiers in bidirectional configuration. The node that will report a “LD Input LOS” alarm is node B only. A “LD Input LOS” alarm indicates that the input signal to the laser diode (LD) of an amplifier is lost or below the threshold3. In this case, node B will not receive any signal from node A due to the fiber cut, and will generate this alarm. Node A will not report this alarm, because it can still receive a signal from node C through the other fiber. Node C will not report this alarm either, because it is not directly affected by the fiber cut between node A and node B. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Troubleshooting Guide for Synchronous Digital Hierarchy - Cisco

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

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 payload type setting is an attribute that is recorded within the client payload and can be set automatically or manually. The payload type setting indicates the type of client signal that is carried by the OTN frame, such as Ethernet, Fibre Channel, or SDH/SONET. The payload type setting can be used for service identification and performance monitoring purposes. The payload type setting can be set automatically by the ML-Series card, which can detect the client signal type and encode it in the payload header. Alternatively, the payload type setting can be set manually by the user using the command config interface encmode payloadtype , where  is the client interface name,  is the encapsulation mode, such as GFP-F or BMP, and  is the client signal type, such as 10GE LAN or FC-1200. The other options are incorrect because they either state that the payload type setting is recorded within the OTN overhead, which is not true, or that it must be entered manually, which is not necessary. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

The command config powermgmt egress 1/2 adjust status is used to enable or disable the power adjustment feature on the specified egress amplifier. The power adjustment feature is a function that automatically adjusts the output power of an amplifier to compensate for changes in the input power or the number of channels. This feature can be enabled or disabled on both ingress and egress amplifiers, depending on the network configuration and requirements1. Therefore, the statement C is true. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia

The command show interface 1/8/UNEIN detail is 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 as Input Power (dBm) in the output of this command1. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia

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 command config powermgmt ingress 1/10 adjust should 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. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide