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350-029 · Question #43

What is one of the primary overhead fields associated with the Optical Payload Unit (OPU)?

The correct answer is C. Payload Structure Identifier (PSI). Optical Payload Unit (OPU) In order to begin describing the OTN as defined by the ITU G.709 standard, we must first enumerate its critical elements, their termination points, and the way they relate to one another in terms of hierarchy and function. The primary overhead field…

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Question

What is one of the primary overhead fields associated with the Optical Payload Unit (OPU)?

Options

  • Apath monitoring
  • Btandem connection monitoring activation deactivation (TCM ACT)
  • CPayload Structure Identifier (PSI)
  • Dmultiframe alignment signal (MFAS)
  • Esection monitoring

How the community answered

(51 responses)
  • A
    8% (4)
  • B
    4% (2)
  • C
    84% (43)
  • D
    2% (1)
  • E
    2% (1)

Explanation

Optical Payload Unit (OPU) In order to begin describing the OTN as defined by the ITU G.709 standard, we must first enumerate its critical elements, their termination points, and the way they relate to one another in terms of hierarchy and function. The primary overhead field associated with the OPU is the payload structure identifier (PSI). This is a 256-byte multiframe whose first byte is defined as the payload type (PT). The remaining 255 bytes are currently reserved. The other fields in the OPU overhead are dependent on the mapping capabilities associated to the OPU. For an asynchronous mapping (the client signal and OPU clock are different) justification control (JC) bytes are available to Application Note 153Telecom Test and Measurement compensate for clock rate differences. For a purely synchronous mapping (client source and OPU clock are the same), the JC bytes become reserved. Further details on mapping are available in ITU G.709.

Topics

#OTN#OPU#optical overhead#PSI

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