Nokia 4A0-265 Dumps

The command show interface am2125a 1/6/lineout detail is used to retrieve the total output power level of the AM2125A amplifier module. This command displays detailed information about the lineout interface, including the current optical power, wavelength, and status. The total output power level is shown as Output Power (dBm) in the output of this command1. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia

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

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

The exhibit shows a conditions list from the 1830 PSS GUI, which displays the alarms and events that occur on the network elements. The total number of alarms reported is equal to the number of rows that have a red or yellow icon in the Severity column, indicating a critical or major alarm. In this case, there are 7 rows with such icons, so the total number of alarms is 7. The number of service affecting alarms is equal to the number of rows that have a “Yes” valuein the Service Affecting column, indicating that the alarm affects the service quality or availability. In this case, there are 5 rows with such values, so the number of service affecting alarms is 5. The number of conditions is equal to the total number of rows in the table, regardless of their severity or service affecting status. In this case, there are 7 rows in the table, so the number of conditions is 7. References : Optical User Guide - Nokia, Security Target Nokia 1830 Photonic Service Switch (PSS)

The command show wavekey wtsource power displays a list of the expected and measured output power for the channels whose admin state is up. This command is useful to monitor the power levels of the channels that are encoded with Wave Keys, which are unique identifiers for wavelength tracking. The command output shows the channel number, wavelength, Wave Key ID, Wave Key Code, expected output power, measured output power, and power difference for each channel1. The command can be used on both OTs and amplifiers that support WT capability2. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Optical User Guide - Nokia

 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

 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

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

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

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

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

The exhibit shows a diagram of a network with two nodes, Node A and Node B, connected by a fiber span. The diagram also shows the power readings at different points of the span. The calculated span loss from Node A to Node B is the difference between the output power at Node A and the input power at Node B. According to the diagram, the output power at Node A is +3.5 dBm and the input power at Node B is -4.5 dBm. Therefore, the span loss from Node A to Node B is 3.5 - (-4.5) = 8.0 dB.