Nokia 4A0-255 問題練習

Question No : 1
Which if the following statements about Recovery Time Objective (RTO) and Recovery Point Object Point Objective (PRO) is FALSE?

• A.RTO/PRO define business continually requirements for data center.
• B.RTO/PRO defined the acceptable amount of data (in bits) that can be lost after a failure.
• C.Data center mirroring has the most critical level of RT
• D.RPO among DC applications.
• E.Tier ½ data centers have stricter RTO/PRO requirements than Tire ¾.

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Question No : 2
Which of the following statements about GMPLS features is FALSE?

• A.GMPLS is able to manage the optical network through the DC
• B.GMPLS is able to control OTN networks.
• C.GMPLS is able to compute the routing of the optical channels.
• D.GMPLS is able to automatically provision the optical channels.

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Question No : 3
Which of the following is recommended to reduce the latency of a 30km long link?

• A.DCM-free amplifiers
• B.Soft-decision FEC
• C.Low-noise amplifiers
• D.L1 encryption

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Question No : 4
Which of the following can be detected through power monitoring with an Optical Time Domain Reflect meter?

• A.Intrusions on fibers
• B.Power injection one channel
• C.Hacking of L1 encryption
• D.Intrusions in the cryptographic keys

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Question No : 5
Suppose there is a 40 Gbit/s signal which has a symbol rate of Gbaud/s.
Which modulation format is being used?

• A.QPSK
• B.BPSK
• C.4QAM
• D.DP-QPSK

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Question No : 6
What is precision Time Protocol (PTP) designed for?

• A.Precise time measurements
• B.Synchronization of encryption entities
• C.Shortest path discovery
• D.Packet-based timing distribution

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Question No : 7
Consider the exhibit that shows the OTN frame structure.



Which of the following sets of label is correct?

• A.OUT: B: ODU: C: OPU: D: OPU
• B.OUT: B: ODU: C: OPU: D: OCH
• C.OPU: B: OTU: C: ODU: D: OPU
• D.ODU: B: OYU: C: OPU: D: OPU

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Question No : 8
Which of the following best describes Flexgrid?

• A.Flexgrid is based on flexible amplification stages
• B.Flexgrid uses flexible guardband that can take any spacing.
• C.Flexgrid is defined on a frequency grid spacing based on ,multiples of 12.5 GHz.
• D.Flexgrid allows channel bandwidth central frequencies and guardband to take any value in the spectrum range.

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Question No : 9
Which of the following statements about the recovery time for protection and restoration combined (PRC) is correct?

• A.PRC can be as fact as sub-network connection protection (SNCP)
• B.PRC is as fast as restoration mechanisms.
• C.PRC has a recovery time that depends on the broken links.
• D.PRC has a typical recovery time greater than 50 ms.

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Question No : 10
Which of the following best describes Four Wave Mixing (FWM)?

• A.FWM is a linear impairment that produces crosstalk four adjacent wavelengths are used.
• B.FWM is a non-linear impairment that produces crosstalk at the sum and difference of two wavelengths.
• C.FWM is a non-linear impairment resulting from varying velocities at different frequencies.
• D.FWM is a linear impairment resulting from pulses broadening over ultra-longdistances

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