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500-205 · Question #46

Which type of protocol encapsulation do IP-over-DWDM interfaces feature?

The correct answer is B. G.709. G.709 (Option B) is correct because IP-over-DWDM interfaces use the ITU-T G.709 standard, also known as the Optical Transport Network (OTN) protocol, which provides a digital wrapper for encapsulating IP/Ethernet frames over Dense Wavelength Division Multiplexing optical links…

Optical Network Fundamentals

Question

Which type of protocol encapsulation do IP-over-DWDM interfaces feature?

Options

  • AG.853
  • BG.709
  • CSONET/SDH
  • DATM

How the community answered

(31 responses)
  • A
    3% (1)
  • B
    94% (29)
  • C
    3% (1)

Explanation

G.709 (Option B) is correct because IP-over-DWDM interfaces use the ITU-T G.709 standard, also known as the Optical Transport Network (OTN) protocol, which provides a digital wrapper for encapsulating IP/Ethernet frames over Dense Wavelength Division Multiplexing optical links - offering FEC, performance monitoring, and management overhead natively.

Why the others are wrong:

  • A. G.853 - This ITU-T standard relates to optical connector characteristics, not encapsulation protocols.
  • C. SONET/SDH - These are legacy TDM transport protocols used in older optical networks; modern IP-over-DWDM architectures replaced them with OTN (G.709) precisely to support higher bandwidth and better error correction.
  • D. ATM - Asynchronous Transfer Mode is a cell-based switching technology from a previous generation of networking; it is not used for IP-over-DWDM encapsulation.

Memory tip: Think of G.709 as the "digital wrapper" or "OTN envelope" - it wraps IP traffic going over DWDM optical wavelengths. If you remember OTN = G.709 = DWDM's encapsulation friend, you'll lock this in for the exam.

Topics

#G.709#IP-over-DWDM#OTN Encapsulation#DWDM

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