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RCDD · Question #347

If looking to specify an optical fiber backbone within a building going 275 m (902 ft) between the equipment room (ER) and the telecommunications room (TR), what type of fiber should be specified to…

The correct answer is C. 50 micron laser optimized multimode. For a 275-meter intra-building 10GbE backbone, laser-optimized 50 micron multimode (OM3 or OM4) is the correct choice because it supports 10GBase-SR at that distance while remaining cost-effective.

Information Transport Systems (ITS) Distribution

Question

If looking to specify an optical fiber backbone within a building going 275 m (902 ft) between the equipment room (ER) and the telecommunications room (TR), what type of fiber should be specified to support a 10 GB ethernet application?

Options

  • AOM1
  • B50 micron multimode
  • C50 micron laser optimized multimode
  • D62.5 micron multimode

How the community answered

(23 responses)
  • A
    4% (1)
  • B
    9% (2)
  • C
    78% (18)
  • D
    9% (2)

Why each option

For a 275-meter intra-building 10GbE backbone, laser-optimized 50 micron multimode (OM3 or OM4) is the correct choice because it supports 10GBase-SR at that distance while remaining cost-effective.

AOM1

OM1 (62.5 micron multimode) supports 10GBase-SR for only approximately 33 meters, far below the 275-meter requirement.

B50 micron multimode

Standard 50 micron multimode (OM2) supports 10GBase-SR for only approximately 82 meters, insufficient for a 275-meter backbone.

C50 micron laser optimized multimodeCorrect

Laser-optimized 50 micron multimode fiber (OM3) supports 10GBase-SR at distances up to 300 meters, comfortably covering a 275-meter intra-building backbone run. It uses 850 nm VCSELs specifically optimized for this fiber type, providing reliable 10GbE performance without the added cost of singlemode transceivers. This is the industry-standard recommendation for 10GbE within buildings where distances fall within the OM3/OM4 range.

D62.5 micron multimode

62.5 micron multimode is OM1 fiber, which supports 10GBase-SR for only approximately 33 meters, making it unsuitable for this run.

Concept tested: Fiber optic type selection for intra-building 10GbE backbone

Source: https://standards.ieee.org/ieee/802.3ae/1397/

Topics

#OM3 laser optimized multimode#10GB Ethernet#backbone fiber#building cabling

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