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Difficulty: MediumTroubleshooting Physical Cabling and Connectors

A network technician needs to pinpoint the precise location of a conductor break in a 90-meter Category 6 UTP cable run hidden behind drywall. A basic wire mapper confirms an open circuit on pin 3, but cannot determine how far along the cable the fault occurred. Which diagnostic tool should the technician use to measure the exact distance to the cable break?

  1. Time-Domain Reflectometer (TDR)Answer
  2. B
    Tone generator and probe trace kit
  3. C
    Optical Power Meter (OPM)
  4. D
    Protocol analyzer

Answer

Time-Domain Reflectometer (TDR)
A Time-Domain Reflectometer (TDR) is specifically designed to send electrical pulses through copper media and analyze the reflected signals. By calculating the time delay of the reflection against the cable's velocity of propagation, a TDR precisely measures the distance to physical cable breaks, kinks, or impedance mismatches.

Step-by-Step Solution

1
Identify the physical layer fault and diagnostic goal
The goal is to determine the exact distance along a copper cable run where a conductor break (open circuit) is located.
Basic wire mappers only confirm electrical continuity across pins but lack signal reflection measurement capabilities.
2
Select the appropriate diagnostic tool designed for copper cable fault location
Select a Time-Domain Reflectometer (TDR).
A TDR transmits a signal pulse along copper conductors and measures the elapsed time for reflections caused by impedance changes (such as an open circuit or short) to return, calculating distance based on nominal velocity of propagation.

Key Concept

Pinpointing Copper Cable Fault Locations with a TDR
Estimated Time:1m 0s
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Topics

Troubleshooting Physical Cabling and Connectors

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