試験準備には欠かさない！4A0-220問題解答で4A0-220試験問題集
リアルNokia 4A0-220試験問題 [更新されたのは2023年]
質問 # 11
Which label is swapped in an MPLS label stack at an intermediate node?
- A. The label with the highest value
- B. The label with the lowest value
- C. The label on the bottom
- D. The label on the top
正解：D
解説：
Explanation
The label on the top of the MPLS label stack is swapped at an intermediate node. This is because the top label is the one that is visible to the node and determines the forwarding decision. The node looks up the top label in its label forwarding table and swaps it with a new label that corresponds to the next hop or destination. The node then forwards the packet to the next node, which repeats the same process. The bottom label is only used to indicate the end of the label stack and is not swapped. References : [Nokia GMPLS-controlled Optical Networks Course | Nokia], [MPLS Label Stack - Nokia]
質問 # 12
What is the Commissioning File in GMRE nodes?
- A. A control checklist for the operator
- B. A file with target values that determine whether a given LSP is possible
- C. A file of optical impairment parameters for power balance
- D. A file with commissioned GMRE nodes for NPA implementation
正解：B
解説：
Explanation
The Commissioning File in GMRE nodes is a file with target values that determine whether a given LSP is possible. The Commissioning File contains parameters such as power, OSNR, Q-factor, and dispersion that are used to evaluate the feasibility of an LSP request. The Commissioning File is generated by the Network Planning Application (NPA) based on the network design and optical impairments. The Commissioning File is uploaded to each GMRE node and is used by the CSPF algorithm to find a suitable path for the LSP. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, Network Planning Application (NPA) | Nokia
質問 # 13
Which of the following information is present in every GMPLS-enabled node?
- A. The bandwidth of each client path in the entire network
- B. The state of each link in the entire network
- C. The list of LSPs created in the entire network
- D. The frequency of each client path in the entire network
正解：B
解説：
Explanation
GMPLS-enabled nodes use routing protocols, such as OSPF-TE or ISIS-TE, to exchange information about the topology and the state of the links in the network12. This information includes the link attributes, such as bandwidth, wavelength, protection, and shared risk link groups (SRLGs)3. The state of each link indicates whether it is up or down, available or reserved, and so on. This information is used by GMPLS-enabled nodes to compute feasible paths for LSPs and to avoid routing loops or conflicts. The bandwidth and the frequency of each client path are not present in every GMPLS-enabled node, but only in the ingress and egress nodes that initiate and terminate the LSPs. The list of LSPs created in the entire network is also not present in every GMPLS-enabled node, but only in the nodes that are involved in the LSPs or that maintain a global view of the network. References:
* 1: GMPLS - Nokia
* 2: Generalized Multi-Protocol Label Switching - Wikipedia
* 3: Nokia GMPLS-controlled Optical Networks Course | Nokia
質問 # 14
What is the meaning of Generalized in GMPLS?
- A. The label can assume an extended value range, and is not constrained as it is with MPLS
- B. Switching can be based on values other than the label
- C. GMPLS can be used for traffic types other than data packets
- D. Unlike MPLS, GMPLS supports multi-vendor networks
正解：C
解説：
Explanation
GMPLS stands for Generalized Multi-Protocol Label Switching, which is a protocol suite that extends MPLS to control different types of switching technologies, such as optical, TDM, and packet switching1. The meaning of Generalized in GMPLS is that it can be used for traffic types other than data packets, such as wavelengths, time slots, or fibers2. GMPLS can also use implicit labels that are derived from the physical properties of the data stream, such as wavelength or timeslot, instead of explicit labels that are carried in the packet header3. This allows GMPLS to support various transport networks and applications, such as optical transport networks (OTN), wavelength switched optical networks (WSON), and automatic switched optical networks (ASON)4. References:
* 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 2: What is MPLS and GMPLS? - Metaswitch
* 3: Generalized Multi-Protocol Label Switching - Wikipedia
* 4: GMPLS - Nokia
質問 # 15
What is the function of the OSPF-TE protocol?
- A. To create an MPLS tunnel between two or more end points
- B. To exchange with other nodes data about the state of links
- C. To monitor the availability of the links interconnecting adjacent nodes
- D. To assign different priority to various types of transported signals
正解：B
解説：
Explanation
The OSPF-TE protocol is an extension of the Open Shortest Path First (OSPF) protocol that is used to exchange information about the state of links in a GMPLS network. OSPF-TE advertises link attributes such as bandwidth, latency, priority, protection, or switching capabilities to other nodes in the same area. OSPF-TE enables nodes to build a Traffic Engineering Database (TED) that contains the topology and resource information of the network. OSPF-TE helps nodes to perform CSPF calculations and establish LSPs using RSVP-TE signaling. References : Open Shortest Path First - Wikipedia, Understand Open Shortest Path First (OSPF) - Design Guide, RSVP-TE and OSPF-TE extensions for GMPLS
質問 # 16
What is Tunnel Property Heritage?
- A. Maximum allowed bandwith is propagated from HO to LO LSPs.
- B. A restored tunnel inherits the ODUk flows.
- C. Cost, SRLG, and Color properties are propagated from HO to LO LSPs.
- D. The hierarchy tunnels cannot be nested unless they share the same properties.
正解：C
解説：
Explanation
Tunnel Property Heritage is a feature of GMRE that allows the propagation of certain properties from higher order (HO) LSPs to lower order (LO) LSPs in a multi-layer network. These properties include cost, SRLG, and color. Cost is a metric that reflects the preference of using a certain link or path for routing. SRLG is a set of links that share a common risk of failure. Color is an attribute that can be used to group or filter LSPs based on service classes or customer profiles. By propagating these properties from HO to LO LSPs, GMRE can ensure that the end-to-end LSPs are consistent and optimal across different layers34. References:
* 3: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 4: GMPLS - Nokia
質問 # 17
What is the purpose of the Upstream Label Object in RSVP-TE?
- A. It allows for a label to be suggested to provision bidirectional LSPs.
- B. It indicates the LSP flow direction.
- C. It allows a node to restrict the labels that may be used downstream.
- D. It signals resource reservation information to upstream nodes.
正解：A
解説：
Explanation
The Upstream Label Object in RSVP-TE is an optional object that allows a node to suggest a label to its upstream neighbor for the purpose of provisioning bidirectional LSPs. The upstream label object is carried in the Resv message and contains the label value that the node wants to use for receiving traffic from its upstream neighbor. The upstream neighbor can accept or reject the suggested label based on its local policy and resource availability. The upstream label object simplifies the label allocation process for bidirectional LSPs and avoids the need for additional signaling messages. References : RSVP-TE - Hewlett Packard Enterprise, RSVP - Nokia
質問 # 18
Which categories of protocols are included in the GMPLS technology?
- A. Signaling, routing, and forwarding
- B. Link management, signaling, and switching
- C. Routing, signaling, and link management
- D. Routing, grooming, and signaling
正解：C
解説：
Explanation
The GMPLS technology includes three categories of protocols: routing, signaling, and link management.
Routing protocols are used to exchange information about the network topology, resources, and constraints among the nodes. Signaling protocols are used to establish, modify, and release Label Switched Paths (LSPs) across the network. Link management protocols are used to verify the connectivity and status of the links between adjacent nodes. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, 3. GMPLS
- Nokia
質問 # 19
How is the GMRE functionality guaranteed in Nokia equipment?
- A. Redundant LAN cables guarantee GMRE functionality
- B. Rack redundancy guarantees GMRE functionality in case of a power outage
- C. The specific software configuration guarantees GMRE functionality
- D. Controller redundancy guarantees GMRE functionality
正解：D
解説：
Explanation
The GMRE functionality is guaranteed in Nokia equipment by controller redundancy. The controller is the hardware component that runs the GMPLS software and controls the switching fabric of the node. Each node has two controllers, one active and one standby, that synchronize their states and databases. If the active controller fails, the standby controller takes over and ensures the continuity of the GMRE functionality. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, 1830 Photonic Service Switch (PSS) | Nokia
質問 # 20
What is the GMRE node address?
- A. The OSPF-TE broadcast IP used to flood the link adjacency information
- B. The IP address for communication between NEs
- C. The LMP Control Channel ID. This field contains the IPv4 address of the ingress LER as a global unique identifier
- D. An IP address for CORBA communication with the NMS
正解：B
解説：
Explanation
The GMRE node address is the IP address for communication between network elements (NEs) in a GMPLS-controlled optical network. The GMRE node address is also known as the GMRE loopback address or the GMPLS node IP. It is used by GMPLS protocols such as LMP and RSVP to identify and communicate with other GMRE nodes. The GMRE node address is configured on each NE and is advertised by OSPF-TE to other nodes in the same area. References : Nokia 1830 PSS-4, PSS-8, PSS-16 and PSS-32 Platforms - NATO, 1830 PSS Identifiers
質問 # 21
What does an SNC state of lower case "n" mean for a resource in NFM-T?
- A. Indicates it's using a link other than the Nominal
- B. Indicates the nominal resource on a TE-link that is not in use
- C. Indicates if s a higher alarm state level
- D. Indicates it's currently using the Nominal resource assigned to it
正解：B
解説：
Explanation
The SNC state is a parameter that indicates the status of a resource in a GMPLS network. A resource can be a link, a wavelength, a timeslot, or a fiber. The SNC state can have different values, such as N, n, P, p, R, r, and so on. Each value has a specific meaning and implication for the resource and the LSP that uses it. The SNC state of lower case "n" means that the resource is the nominal resource on a TE-link that is notin use. A nominal resource is the default or preferred resource that is assigned to an LSP when it is created. A TE-link is a logical link that represents a set of resources that share the same attributes and constraints. A TE-link can have multiple resources, such as wavelengths or timeslots, but only one of them can be the nominal resource.
If an LSP is using a resource other than the nominal resource on a TE-link, it means that the LSP has been rerouted or switched due to a failure or a constraint violation. In this case, the SNC state of the nominal resource will be "n", indicating that it is not in use by any LSP12. References:
* 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 2: Nokia Network Functions Manager for Transport User Guide | Nokia
質問 # 22
What does the SNC state with an uppercase "N" mean in a resource in NFM-T?
- A. Indicates it's using a link other than the Nominal
- B. Indicates the nominal resource on a TE-link that is not in use
- C. Indicates if s a higher alarm state level
- D. Indicates it's currently using the Nominal resource assigned to it
正解：D
解説：
Explanation
The SNC state with an uppercase "N" means that the resource is currently using the nominal resource assigned to it. As explained in the previous question, a nominal resource is the default or preferred resource that is assigned to an LSP when it is created. If an LSP is using the nominal resource on a TE-link, it means that the LSP has not been rerouted or switched due to any failure or constraint violation. In this case, the SNC state of the resource will be "N", indicating that it is in use by an LSP12. References:
* 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 2: Nokia Network Functions Manager for Transport User Guide | Nokia
質問 # 23
What is a Label Switched Path (LSP)?
- A. A switched protection path
- B. The path created by MPLS nodes
- C. A High Order Container for client signal
- D. A protocol used by nodes to exchange information about the state of labels
正解：B
解説：
Explanation
A Label Switched Path (LSP) is the path created by MPLS nodes that use labels to forward packets across the network. A label is a short identifier that is attached to each packet and indicates the next hop or destination of the packet. The nodes use a label forwarding table to switch packets based on their labels, without inspecting the packet headers. This can improve the performance, security, and quality of service of the network. An LSP can be established by using GMPLS protocols such as OSPF-TE and RSVP-TE, which exchange information about the network topology, resources, and constraints. References : Nokia GMPLS-controlled Optical Networks Course | Nokia, GMPLS - Nokia
質問 # 24
How can you modify the SNC Nominal Route in NFM-T?
- A. By changing the SRG constraints
- B. By using the Constraint Wizard to modify the constraints
- C. By using the Reroute Wizard to modify the constraints
- D. By putting the LSP in Test mode and moving traffic
正解：B
解説：
Explanation
The SNC Nominal Route is the default or preferred route that is assigned to an LSP when it is created. The SNC Nominal Route is determined by the constraints that are specified by the user during the LSP creation process, such as cost, SRLG, color, bandwidth, protection, and regeneration. The user can modify the SNC Nominal Route in NFM-T by using the Constraint Wizard, which is a tool that allows the user to change the constraints for an existing LSP. The Constraint Wizard will then compute a new SNC Nominal Route based on the modified constraints and update the LSP accordingly34. References:
* 3: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 4: Nokia Network Functions Manager for Transport User Guide | Nokia
質問 # 25
What is the Feasibility File in GMRE nodes?
- A. A control checklist for the operator
- B. A file of optical impairment parameters for power balance
- C. A file with commissioned GMRE nodes for NPA implementation
- D. A file with target values that determine whether a given LSP can be routed
正解：D
解説：
Explanation
The Feasibility File is a file that contains a set of target values for various optical impairment parameters, such as OSNR, CD, PMD, and PDL, that are used to determine whether a given LSP can be routed through the GMRE network. The Feasibility File is generated by the Network Planning Application (NPA) based on the network design and the service requirements. The Feasibility File is then loaded into the GMRE nodes and used by the GMPLS routing engine to perform feasibility checks for LSP requests. The Feasibility File ensures that the LSPs are routed in accordance with the network plan and the optical performance criteria12.
References:
* 1: Nokia GMPLS-controlled Optical Networks Course | Nokia
* 2: GMPLS - Nokia
質問 # 26
Which of the following parameters is not considered when restoring an LSP?
- A. Reservation priority
- B. Maximum latency
- C. Equipment vendor
- D. Coloring
正解：C
解説：
Explanation
The equipment vendor is not a parameter that is considered when restoring an LSP. Restoration is the process of re-establishing an LSP after a failure by using an alternative path that meets the same constraints as the original LSP. The parameters that are considered when restoring an LSP include coloring, reservation priority, maximum latency, bandwidth, protection type, and other QoS attributes. The equipment vendor does not affect the restoration process as long as the nodes support GMPLS protocols and interoperate with each other. References : RFC 4427 - Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS), [Nokia GMPLS-controlled Optical Networks Course | Nokia]
質問 # 27
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Nokia 4A0-220認定試験は、90分以内に完了する必要がある60の複数選択質問で構成されています。試験は英語で利用でき、オンラインまたはテストセンターで撮影できます。試験に合格するには、候補者は少なくとも70％を獲得する必要があります。成功した候補者は、GMPLS制御光ネットワークの専門知識を認識する証明書を受け取ります。
4A0-220合格させる試験問題集には更新されたのは2023年：https://www.goshiken.com/Nokia/4A0-220-mondaishu.html
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