Free Nokia Advanced Optical Network Design Exam 4A0-255 Exam Practice Test

Which of the following statements about the recovery time for protection and restoration combined (PRC) is correct?

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

Which of the following statements about power commissioning system is most accurate?

• A system must be either linear or a ring. A system can stop if there is a through communication in a node.
• A system must be a ring only A system can stop if there is a through connection in a node.
• A system must be a ring only A system cannot stop if there is a through connection in a node.
• A system must be either linear or a ring A system cannot stop if there is a through connection in a node

Which of the following statements about Bit Error Rate (BER) is correct?

• BER is the ratio of redundant bits to correct bits.
• BER is measured at both the transmitted and receiving ends.
• BER can be measured before after the FEC decoding.
• BER can be accurately measured in a short period of time , for any rate.

Which of the following statements about an alien wavelength at 10G is correct?

• It is an optical signal generated by FWM impairment.
• It has similar optical performance across multiple vendors equipment at 10G.
• It can be measured by a VAC card.
• It does not support Wavelength tracker.

Which of the following is recommended to reduce the latency of a 30km long link?

• DCM-free amplifiers
• Soft-decision FEC
• Low-noise amplifiers
• L1 encryption

Which of the following is NOT an advantage of super-channels?

• Improved spectral efficiency
• Simplified management of the carriers
• Narrower spacing between carries of the super-channel
• Impairment-free transmission

What is guardband required for?

• To reduce the impact of chromatic dispersion.
• To properly use the available bandwidth of the fibers.
• To enable each channel to support a higher modulation format.
• To reduce non-linear impairments between coherent and non-coherent channels.

Which of the following statements about the management plane data Communications Network (DCN) is correct?

• The management plane DCN uses in-band communication.
• The management plane DCN can be connected to each NEs via OSS/OBS interface.
• The management plane DCN can be connected to each NEs directly.
• The management plane DCN enables direct communication between the NEs.

Which of the following is NOT a functionality provided by a coherent receiver?

• Analog-to-digital conversion (ADC)
• Digital signal processing (DSP)
• Mixing
• Demultiplexing

Consider the exhibit. The grey sites (Site 1 through Site6) from an existing network, which will be extended by adding Site7 and Site8. Which of the following is NOT a common source of interoperability issues for this network extension?

• Spectrum grid of the extension
• Fiber connectors at Site6
• Cascading in the existing network
• Regeneration requirements at Site5