4A0-205 시험 - Nokia실제시험문제와 답 - 40문항

Question No : 1

When monitoring the quality of the received signal in WDM, an open eye indicates:

A.Low noise
B.High distortion
C.High jitter
D.Presence of high inter-symbolic interference

정답:
Explanation:
An open eye pattern indicates that the signal is not affected by noise, and the received signal is of high quality. This is because an open eye pattern is the result of a signal that is aligned in time, and is not affected by noise or other distortions.
References:
✑ "Optical Fiber Communications" by Gerd Keiser
✑ "Fiber-Optic Communications Technology" by Djafar K. Mynbaev ✑ "Optical Communications" by Gerd Keiser

Question No : 2

What is the OAMP LAN interface?

A.It is an RJ-45 interface (a common Ethernet port) used for cascading 1830 PSS nodes (e.g., external shelves)
B.It is an RJ-45 interface (a common Ethernet port) that has to be configured with an IP address for node reachability and management
C.It is an RJ-45 interface (common Ethernet port) used to connect one or more client ports (e.g., 1Gb/s or legacy 100Mbit/s client flows)
D.It is an RJ-45 interface (a common Ethernet port) used to export active alarms to an external device, typically equipped with several LEDs

정답:
Explanation:
It is an RJ-45 interface (a common Ethernet port) that has to be configured with an IP address for node reachability and management. This interface is used to connect the OAMP node to the LAN, allowing it to be managed and monitored remotely.

Question No : 3

Which of the following is an example of optical protection mechanism?

A.Optical regeneration (e.g., back-to-back regeneration)
B.OSNCP (e.g., via Y-cable or OPS card)
C.GMPLS-enabled SBR
D.GR and SBR combined

정답:
Explanation:
It can be implemented through the use of a Y-cable or an optical protection switch (OPS) card, which allows for the switching of traffic to a secondary path in the event of a failure on the primary path. This type of protection is commonly used to protect against
fiber cuts and other types of physical layer failures in the optical transport network.

Question No : 4

What is the purpose of the NFM-T node synchronization?

A.The partial or full node synchronization allows several entities/items defined at node level to be retrieved into the NFM-T database (upload).
B.The partial or full node synchronization allows several entities/items defined at NFM-T level to be written into the node database (download).
C.The partial or full node synchronization allows several entities/items defined at EPT level to be retrieved into the NFM-T database (upload from design).
D.The partial or full node synchronization allows several entities/items defined at NFM-T level to be exported into an XML file, to be used as input for EPT (download to design).

정답:
Explanation:
NFM-T node synchronization is a process to ensure that the NFM-T database and the actual network nodes have consistent data. A full or partial node synchronization uploads the data from the node into the NFM-T database, ensuring that the NFM-T's view of the network is accurate and up to date.

Question No : 5

What is the meaning of first, second, and third window in the optical fiber propagation context?

A.These windows correspond to three different minimum and maximum optical power levels used for optical transmission.
B.These windows are three different wavelength intervals where the WDM optical transmission occurs.
C.These three windows are three different angles of incidence of the light injected by the laser into the fiber.
D.Different optical transmission windows correspond to different safety requirements and rules for the related lasers operating with these windows.

정답:
Explanation:
In optical fiber propagation context, the first, second, and third window refer to different wavelength intervals where the WDM (Wavelength Division Multiplexing) optical transmission occurs.
The first window is the lowest loss window and is typically in the range of 1300-1324nm.
This is the most commonly used window for long-haul communications.
The second window is the 1550 nm window and is the most widely used window for long-haul and ultra-long-haul communications. This window has a lower attenuation than the first window, but it also has more dispersion, which can limit the maximum transmission distance.
The third window is the range of 1625-1675 nm, it is also called the L-band window. This window has lower attenuation than the first and second window but its usage is limited due to the high cost of equipment and lack of commercial devices.
These windows are used in WDM systems to increase the capacity of the fiber by transmitting multiple channels of data at different wavelengths on the same fiber. A,C,D are not correct as they are not related to the meaning of first, second, and third window in the optical fiber propagation context.
Reference:
Nokia Optical Networking Fundamentals, Nokia Press (ISBN:978-1-4822-8109-4)
https://www.nokia.com/networks/solutions/optical-networking/
https://en.wikipedia.org/wiki/Wavelength-division_multiplexing

Question No : 6

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

정답:
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 No : 7

What is a Shared Risk Group (SRG)?

A.A set of fibers that share the same latency risk
B.A set of boards that share the same failure risk
C.A set of nodes that share a common risk of hardware failure
D.A set of network resources that share a common failure risk

정답:
Explanation:
According to the Nokia Optical Networking documentation, a Shared Risk Group (SRG) is defined as "a set of network resources that share a common failure risk. When a resource in an SRG fails, the other resources in the group are also affected." This can include fibers, boards, nodes, and other network resources. The SRG concept is used in network design and protection mechanisms to ensure survivability and minimal impact on service in case of a failure.

Question No : 8

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

정답:
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 No : 9

With reference to trails and services, which of the following sentences is correct?

A.Trails are transported over services; that is, trails are clients with respect to services.
B.A trail can interconnect three ports, while a service always two.
C.Services are transported over trails; that is, services are clients with respect to trails.
D.A service is always associated to a single wavelength, while a trail can involve multiple wavelengths.

정답:
Explanation:
Services are transported over trails; that is, services are clients with respect to trails. A service is a logical connection that is used to transport data from one point to another. It is created over a trail, which is a physical connection that is established by using multiple wavelengths. As such, services are clients with respect to trails, as they are transported over them.

Question No : 10

Which sentence about NFM-T is correct?

A.NFM-T fully supports LO, LI, L2 and GMPLS applications and it is mainly focused on 1830 PSS, as well as other older product families
B.NFM-T fully supports optical and IP nodes
C.NFM-T is used to design and manage optical network
D.NFM-T is used to provision optical services havingIP nodes as extremities

정답:
Explanation:
Network Function Manager for Transport (NFM-T) is a comprehensive network management system that supports a variety of applications including Layer 0 (LO), Layer 1 (L1), Layer 2 (L2), and Generalized Multi-Protocol Label Switching (GMPLS). It's primarily used for managing the 1830 Photonic Service Switch (PSS) series, but it also supports other older product families.

Question No : 11

What is the metro area network?

A.The metro area network is that portion of network that passes through a city to provide connections to several customers.
B.The metro area network is located between access and core domains.
C.The metro area network is made of OCS/SWDM nodes only, as no pure photonic nodes are used here.
D.The metro area network is located in between two access area networks and made of photonic nodes only (no OCS/SWDM nodes are used there).

정답:
Explanation:
A Metropolitan Area Network (MAN) typically spans a city or campus and is larger than a local area network (LAN) but smaller than a wide area network (WAN). It often serves as the link between access and core networks, aggregating traffic from multiple access networks and transporting it to the core network.

Question No : 12

Is it possible to mix PSS-24x and PSS-8x shelves In an SWDM configuration?

A.Yes, as both can be equipped within the same node
B.No, as they are not compatible and cannot be used within the same node
C.Yes, but the PSS-24X shelf must be configured as a master
D.Yes, but the PSS-8X shelf must be configured as a master

정답:
Explanation:
PSS-24x and PSS-8x are Nokia Photonic Service Switches that can be equipped within the same node. They have different capacities but can coexist in the same configuration.

Question No : 13

What does it take to get connected to the NSP platform?

A.A browser and the NSP IP address; and from the landing page, the NSP application should be downloaded and launched.
B.A browser and the NSP IP address. Then, a browser plugin needs to be installed and the laptop rebooted before the NSP can be correctly reached.
C.A browser, the NSP IP address, and the credentials to access the web-based interface (WebUI).
D.The NSP package should be downloaded from the Nokia website and properly licensed for thespecific workstation to be used.

정답:
Explanation:
To get connected to the Nokia Service Platform (NSP) platform, you need a browser and the NSP IP address. Then, you need the credentials to access the web-based interface (WebUI) for the NSP platform. Once you have these, you can access the NSP platform from a web browser.

Question No : 14

What is the function of a pre-amplifier in an optical network?

A.Through the pre-amplifier, the optical signal is amplified at the receiver side after it travels along the fiber from another node.
B.Through the pre-amplifier, the optical signal is amplified at the transmitter side before it is sent to the line span.
C.Through the pre-amplifier, the optical signal is amplified both the receiver side and at the transmitter side.
D.Through the pre-amplifier, the optical signal is amplified within the node internally to recover internal losses due, for instance, to cascaded filters.

정답:
Explanation:
The main function of a pre-amplifier in an optical network is to amplify the optical signal at the receiver end after it has travelled along the fiber from the transmitter side. This ensures that the signal power is strong enough for detection at the receiver side.

Question No : 15

What is a degree-1 node?

A.A node with only one direction and therefore a terminal node
B.A node with only one express channel and therefore made of two sides
C.A node with only east and west sides without directions towards north and south
D.A node with one direction only and therefore used as In-Line-Amplifier (ILA)

정답:
Explanation:
A degree-1 node is a node that only has one direction, and it is therefore a terminal node. This means that the node only has one input and one output port. It does not have any other ports to connect to other nodes or fibers. This is a common feature of some optical transport networks, such as ring networks, where a degree-1 node serves as the endpoint of the ring.

Nokia 4A0-205 시험