Practice Free 4A0-205 Exam Online Questions
Question #1
Where can the user set the long-haul WT decoder parameter, when designing a network with EPT?
- A . In the network parameters
- B . In the optimization parameters
- C . In the NE parameters
- D . In the audit menu
Correct Answer: C
C
Explanation:
The long-haul WT decoder parameter can be set in the NE parameters when designing a network with EPT. This parameter is used to adjust the sensitivity of the decoder and can help to improve the accuracy of the measurements for long-haul WTs. The Network Element (NE) parameters in EPT (Element Planning Tool) are used to configure various settings and options for the network elements in the network. The long-haul WT decoder parameter is one such setting that can be configured in the NE parameters section. The user can access the NE parameters by navigating to the NE Parameters menu within the EPT interface. The user can then select the appropriate network element and modify the settings as needed. This information can be found in the Nokia guide for EPT.
C
Explanation:
The long-haul WT decoder parameter can be set in the NE parameters when designing a network with EPT. This parameter is used to adjust the sensitivity of the decoder and can help to improve the accuracy of the measurements for long-haul WTs. The Network Element (NE) parameters in EPT (Element Planning Tool) are used to configure various settings and options for the network elements in the network. The long-haul WT decoder parameter is one such setting that can be configured in the NE parameters section. The user can access the NE parameters by navigating to the NE Parameters menu within the EPT interface. The user can then select the appropriate network element and modify the settings as needed. This information can be found in the Nokia guide for EPT.
Question #2
What is an optical switch?
- A . A device that selectively transfers an optical signal from one port to another.
- B . A device that groups multiple lambdas in one multiplexed signal.
- C . A device that selectively transfers an optical ODU frame from one port to another.
- D . A device that converts optical signal to electrical to allow switching through the electrical matrix, and then again to optical towards the next card (and versa).
Correct Answer: A
A
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
In the context of optical networking fundamentals, an optical switch (often referred to as a Photonic Switch or Layer 0 switch) is defined as a device that routes an optical signal―composed of photons― from an input port to one or more output ports without converting it into an electrical signal. This process is known as transparent switching. It operates entirely within the optical domain, maintaining the integrity of the lightwave regardless of the data rate or protocol being carried (e.g., SDH, Ethernet, or OTN).
It is important to distinguish this from Option D, which describes an Electrical or ODU Switch (Layer 1). In a device like the Nokia 1830 PSS-24x, signals are converted to electrical format (O-E-O) to be switched at the ODU (Optical Data Unit) level via a central fabric. While this provides "any-to-any" grooming, a true optical switch (like a WSS found in ROADMs) simply steers the light. The primary advantage of an optical switch is its ability to handle massive amounts of bandwidth with extremely low latency and lower power consumption compared to electrical switching, as it avoids the overhead of repeated O-E-O conversions at intermediate network nodes.
A
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
In the context of optical networking fundamentals, an optical switch (often referred to as a Photonic Switch or Layer 0 switch) is defined as a device that routes an optical signal―composed of photons― from an input port to one or more output ports without converting it into an electrical signal. This process is known as transparent switching. It operates entirely within the optical domain, maintaining the integrity of the lightwave regardless of the data rate or protocol being carried (e.g., SDH, Ethernet, or OTN).
It is important to distinguish this from Option D, which describes an Electrical or ODU Switch (Layer 1). In a device like the Nokia 1830 PSS-24x, signals are converted to electrical format (O-E-O) to be switched at the ODU (Optical Data Unit) level via a central fabric. While this provides "any-to-any" grooming, a true optical switch (like a WSS found in ROADMs) simply steers the light. The primary advantage of an optical switch is its ability to handle massive amounts of bandwidth with extremely low latency and lower power consumption compared to electrical switching, as it avoids the overhead of repeated O-E-O conversions at intermediate network nodes.
Question #3
Is it possible to modify node parameters within the edit EPT menu?
- A . Yes, the user can apply manual changes directly from this view
- B . Yes, but the user can modify only the node name and location
- C . No, this view is used to display a close-up view of the node
- D . Yes, the user can apply manual changes but only for non-GMPLS nodes, as the control plane reserves node resources not editable by the user
Correct Answer: A
A
Explanation:
In the Edit menu of the Engineering and Planning Tool (EPT), the user can manually modify various node parameters. These changes are reflected in the network design.
A
Explanation:
In the Edit menu of the Engineering and Planning Tool (EPT), the user can manually modify various node parameters. These changes are reflected in the network design.
Question #4
Is it possible to open and manage EPT designs that are created with different releases than the release installed on the local workstation?
- A . Only designs created with the current release can be opened and edited.
- B . Only designs created with current and older releases can be opened and edited.
- C . Designs created with an older release can be opened by a current release but cannot make changes.
- D . No restrictions are imposed on the software release.
Correct Answer: B
B
Explanation:
It is possible to open and manage EPT designs that are created with different releases than the release installed on the local workstation, however only designs created with current and older releases can be opened and edited. Designs created with an older release can be opened by a current release but changes cannot be made.
B
Explanation:
It is possible to open and manage EPT designs that are created with different releases than the release installed on the local workstation, however only designs created with current and older releases can be opened and edited. Designs created with an older release can be opened by a current release but changes cannot be made.
Question #5
Which of the following statements about Optical Add/Drop Multiplexers (OADMs) is FALSE?
- A . OADMs allow the user to terminate specific services through transponders.
- B . OADMs allow the user to pass-through specific services at the wavelength optical level (express channels).
- C . OADMs always require O-E-O conversion when passing-through optical channels.
- D . There are two main general classes of OADMs: FOADMs and ROADMs.
Correct Answer: C
C
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
In the context of the Nokia 1830 PSS (Photonic Service Switch) and general WDM principles, the statement that OADMs always require O-E-O (Optical-Electrical-Optical) conversion for pass-through channels is fundamentally incorrect. The primary purpose of an OADM is to provide the ability to "add" or "drop" specific wavelengths while allowing other wavelengths (known as express or pass-through channels) to continue through the node entirely in the photonic domain.
By remaining in the optical layer, these express channels avoid the latency and cost associated with O-E-O conversion. FOADMs (Fixed OADMs) use static filters to achieve this, while ROADMs (Reconfigurable OADMs) use Wavelength Selective Switches (WSS) to dynamically route traffic. O-E-O conversion only occurs at the transponder or muxponder level when a service is terminated (dropped) or initiated (added) to convert the client signal into a compliant DWDM wavelength. Therefore, the efficiency of an optical network relies on the fact that pass-through traffic stays as light, bypassing the need for electrical processing at every node.
C
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
In the context of the Nokia 1830 PSS (Photonic Service Switch) and general WDM principles, the statement that OADMs always require O-E-O (Optical-Electrical-Optical) conversion for pass-through channels is fundamentally incorrect. The primary purpose of an OADM is to provide the ability to "add" or "drop" specific wavelengths while allowing other wavelengths (known as express or pass-through channels) to continue through the node entirely in the photonic domain.
By remaining in the optical layer, these express channels avoid the latency and cost associated with O-E-O conversion. FOADMs (Fixed OADMs) use static filters to achieve this, while ROADMs (Reconfigurable OADMs) use Wavelength Selective Switches (WSS) to dynamically route traffic. O-E-O conversion only occurs at the transponder or muxponder level when a service is terminated (dropped) or initiated (added) to convert the client signal into a compliant DWDM wavelength. Therefore, the efficiency of an optical network relies on the fact that pass-through traffic stays as light, bypassing the need for electrical processing at every node.
Question #6
Which of the following are the main reasons for fiber attenuation?
- A . Refraction and reflection
- B . Scattering and absorption
- C . Chromatic dispersion (CD) and polarization mode dispersion
- D . Small channel spacing
Correct Answer: B
B
Explanation:
Scattering and absorption are the main reasons for fiber attenuation. Scattering occurs when light bounces off the sides of the fiber, while absorption happens when light is absorbed by the glass or other materials that make up the fiber. Chromatic dispersion (CD) and polarization mode dispersion (PMD) are also factors that can cause attenuation, but they are not the main causes. Small channel spacing can also cause attenuation, but it is a secondary factor and is only significant in certain cases.
B
Explanation:
Scattering and absorption are the main reasons for fiber attenuation. Scattering occurs when light bounces off the sides of the fiber, while absorption happens when light is absorbed by the glass or other materials that make up the fiber. Chromatic dispersion (CD) and polarization mode dispersion (PMD) are also factors that can cause attenuation, but they are not the main causes. Small channel spacing can also cause attenuation, but it is a secondary factor and is only significant in certain cases.
Question #7
In which window(s) does the attenuation reach its minimum peak?
- A . First window (850 nm)
- B . Second window (1300 nm)
- C . Third window (1550 nm)
- D . Both first and second windows
Correct Answer: C
C
Explanation:
The third window (1550 nm) is where the attenuation reaches its minimum peak. This is because the materials used in fiber optic cables have minimal absorption in this wavelength range. The first and second windows (850 nm and 1300 nm respectively) have higher attenuation due to the materials used in the fiber optic cables.
C
Explanation:
The third window (1550 nm) is where the attenuation reaches its minimum peak. This is because the materials used in fiber optic cables have minimal absorption in this wavelength range. The first and second windows (850 nm and 1300 nm respectively) have higher attenuation due to the materials used in the fiber optic cables.
Question #8
How many PM bins can be stored, for each data collection point, on PSS systems?
- A . 120 x 15-min bins, 60 x 1-day bins and 1 raw bin.
- B . 200 x 15-min bins, 90 x 1-day bins and 1 raw bin.
- C . 4 x 15-min bins and 1 x 1-day bin.
- D . 33 x 15-min bins, 8 x 1-day bins and 1 raw bin.
Correct Answer: D
D
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
Performance Monitoring (PM) is critical for maintaining the health of a Nokia 1830 PSS network. The system collects data such as FEC corrected bits, optical power levels, and ODU-layer errors. According to Nokia’s standard node management architecture, each data collection point (such as an optical port or an ODU termination point) stores a specific number of historical "bins" locally on the card or the shelf controller.
The standard storage capacity for these PM statistics is 33 x 15-minute bins (covering the last 8 hours and 15 minutes of granular data) and 8 x 1-day bins (covering the last week of daily totals). Additionally, there is 1 raw bin which contains the "current" accumulating data that has not yet been shifted into a completed 15-minute or 24-hour historical bin. This allows network operators using WS-NOC (WaveSuite Network Operations Center) to retrieve recent historical performance data directly from the NE (Network Element) even if the management system was temporarily disconnected. If longer-term history is required, the management system must be configured to poll and archive these bins into its own database before they are overwritten on the hardware.
D
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
Performance Monitoring (PM) is critical for maintaining the health of a Nokia 1830 PSS network. The system collects data such as FEC corrected bits, optical power levels, and ODU-layer errors. According to Nokia’s standard node management architecture, each data collection point (such as an optical port or an ODU termination point) stores a specific number of historical "bins" locally on the card or the shelf controller.
The standard storage capacity for these PM statistics is 33 x 15-minute bins (covering the last 8 hours and 15 minutes of granular data) and 8 x 1-day bins (covering the last week of daily totals). Additionally, there is 1 raw bin which contains the "current" accumulating data that has not yet been shifted into a completed 15-minute or 24-hour historical bin. This allows network operators using WS-NOC (WaveSuite Network Operations Center) to retrieve recent historical performance data directly from the NE (Network Element) even if the management system was temporarily disconnected. If longer-term history is required, the management system must be configured to poll and archive these bins into its own database before they are overwritten on the hardware.
Question #9
What is the purpose of the validate step in the EPT design process?
- A . During this step, the configuration available on the involved network elements is compared with the design provided byEPT.
- B . This step is used to measure optical power performances over an existing network before making changes.
- C . This step is optional and is useful to verify the network element layout before going through the commission step.
- D . During this step, the run design action is triggered for network design consistency check and errors fixing.
Correct Answer: A
A
Explanation:
In the EPT design process, the validate step is crucial to compare the actual configuration of network elements with the design provided by EPT (Engineering Planning Tool). This step ensures that the network has been set up correctly according to the design.
A
Explanation:
In the EPT design process, the validate step is crucial to compare the actual configuration of network elements with the design provided by EPT (Engineering Planning Tool). This step ensures that the network has been set up correctly according to the design.
Question #10
How can a mesh network be upgraded so that more services can be transported?
- A . Configuring new WSS cards is the most effective way to give flexibility and network bandwidth to an existing mesh network.
- B . The Protection and Restoration Combined (PRC) mechanism can enable more bandwidth but only for the protected services.
- C . Upgrading the network to coherent transmission is the only effective way to enable more bandwidth to the existing mesh network.
- D . Upgrading link capacity and/or installing new links provides more bandwidth to the existing mesh network.
Correct Answer: D
D
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
While technologies like WSS (Wavelength Selective Switches) and coherent transmission (100G/200G/400G+) significantly improve the efficiency and reach of a network, the most direct way to increase the total transportable volume of services in a mesh topology is to upgrade link capacity or install new physical links. In Nokia optical planning, upgrading link capacity typically involves moving from a lower-rate system (like 10G) to a higher-rate system (like 100G or 400G) or increasing the number of available wavelengths by expanding from a 40-channel to an 80-channel or 96-channel C-band system.
Adding new links (new fiber spans) creates more degrees in the mesh, providing more paths for traffic and increasing the overall aggregate bandwidth of the network.
Option A refers to flexibility (ROADM functionality) rather than raw capacity.
Option B (PRC) relates to survivability and availability, not capacity expansion. While Option C (coherent transmission) is a powerful method for increasing capacity per wavelength, it is not the "only" way, as adding more fiber (spatial multiplexing) or more channels (spectral density) are also primary methods for scaling a mesh network to handle more services.
D
Explanation:
Comprehensive and Detailed Explanation From Nokia Optical Networking Fundamentals:
While technologies like WSS (Wavelength Selective Switches) and coherent transmission (100G/200G/400G+) significantly improve the efficiency and reach of a network, the most direct way to increase the total transportable volume of services in a mesh topology is to upgrade link capacity or install new physical links. In Nokia optical planning, upgrading link capacity typically involves moving from a lower-rate system (like 10G) to a higher-rate system (like 100G or 400G) or increasing the number of available wavelengths by expanding from a 40-channel to an 80-channel or 96-channel C-band system.
Adding new links (new fiber spans) creates more degrees in the mesh, providing more paths for traffic and increasing the overall aggregate bandwidth of the network.
Option A refers to flexibility (ROADM functionality) rather than raw capacity.
Option B (PRC) relates to survivability and availability, not capacity expansion. While Option C (coherent transmission) is a powerful method for increasing capacity per wavelength, it is not the "only" way, as adding more fiber (spatial multiplexing) or more channels (spectral density) are also primary methods for scaling a mesh network to handle more services.
1 2