Which three characteristics define a touchless ROADM? (Choose three.)

Question

Options

• Acolorless
• Bfixed grid
• Comnidirectional or directionless
• Dcontentionless
• Emultidegree
• Ftwo-degree

• A
  92% (34)
• B
  3% (1)
• E
  5% (2)

Explanation

A touchless ROADM is defined by the "CDC" triad: Colorless, Directionless (omnidirectional), and Contentionless - together these allow any wavelength to be routed to any port in any direction without manual fiber intervention. Colorless (A) means transponders can tune to any wavelength dynamically, eliminating the need to physically swap equipment per channel. Directionless (C) means any add/drop port can connect to any fiber direction without rewiring. Contentionless (D) means multiple transponders can simultaneously use the same wavelength on different ports without signal blocking or conflict.

Why the distractors are wrong:

• B (Fixed grid): Fixed grid is a constraint, not a touchless feature - touchless ROADMs typically use flexible/colorless grids, not rigid frequency assignments.
• E (Multidegree): Multidegree describes how many fiber directions connect to a node - it's a topology property, not a touchless-defining trait; you can have multidegree ROADMs that are not touchless.
• F (Two-degree): Two-degree is the most basic ROADM (one in, one out) and actually limits flexibility - the opposite of the touchless goal.

Memory tip: Remember CDC - Colorless, Directionless, Contentionless - as "the three freedoms" that make a ROADM truly touchless (zero manual intervention needed for reconfiguration).

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