Question 368 of 1,020
Common Networking HardwaremediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is that the switch is power-cycling the phone due to PoE power budget constraints. When a PoE switch’s total power budget is at 95% capacity, it enters a state where it must prioritize power delivery; to prevent an overload that could crash the entire switch, it will intermittently cut power to lower-priority devices like VoIP phones, causing them to reset and drop audio. This scenario directly tests your understanding of Power over Ethernet (PoE) power budgeting, a key concept on the CompTIA A+ Core 1 220-1201 exam. A common trap is assuming the issue is a bad cable or interference, but the clue is the high power budget percentage—the phone isn’t failing, it’s being starved. Remember the mnemonic “95% is a power dive” to recall that near-capacity budgets cause devices to cycle off.

220-1201 Common Networking Hardware Practice Question

This 220-1201 practice question tests your understanding of common networking hardware. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

A user complains that their VoIP phone intermittently loses audio during calls. The phone is connected to a PoE switch. The technician checks the switch and sees that the port's PoE power budget is at 95% capacity. What is the most likely cause of the audio drops?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "most likely"

    Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

Question 1mediummultiple choice
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Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

The switch is power-cycling the phone due to PoE power budget constraints.

This question tests understanding of Power over Ethernet (PoE) power budgeting. When a PoE switch's power budget is near capacity, it may intermittently power down low-priority devices to prevent overload, causing the phone to reset or lose power. The correct answer is that the switch is power-cycling the phone due to power budget constraints.

Key principle: A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • The Ethernet cable is too long, causing signal attenuation.

    Why it's wrong here

    While cable length can cause issues, it would affect all traffic, not just intermittently. The PoE power budget issue is more specific to the intermittent behavior.

  • The VoIP phone is faulty and needs replacement.

    Why it's wrong here

    A faulty phone could cause audio drops, but the high PoE power budget usage suggests a systemic power issue rather than a device defect.

  • The switch is power-cycling the phone due to PoE power budget constraints.

    Why this is correct

    When the PoE power budget is near capacity, the switch may prioritize power delivery and occasionally drop power to lower-priority devices, causing the phone to reset and drop audio.

    Clue confirmation

    The clue word "most likely" in the question point toward this answer.

    Related concept

    Access ports place end devices into a single VLAN.

  • The switch port is configured with a VLAN mismatch.

    Why it's wrong here

    A VLAN mismatch would cause complete loss of network connectivity, not intermittent audio drops. The phone would likely not register at all.

Common exam traps

Common exam trap: an active trunk can still block the VLAN you need

A trunk being up does not prove every VLAN is crossing it. Check allowed VLAN lists, native VLAN mismatch, VLAN existence and access-port assignment.

Detailed technical explanation

How to think about this question

VLAN questions usually combine access-port and trunking clues. The key is to identify whether the issue is local to one switchport, caused by the trunk, or caused by the VLAN not existing where it needs to exist.

KKey Concepts to Remember

  • Access ports place end devices into a single VLAN.
  • Trunk ports carry multiple VLANs between switches.
  • Allowed VLAN lists decide which VLANs can cross a trunk.
  • Native VLAN mismatch can create confusing symptoms.

TExam Day Tips

  • Use show vlan brief to verify access VLANs.
  • Use show interfaces trunk to verify trunk state and allowed VLANs.
  • Do not treat every same-VLAN issue as a routing problem.

Key takeaway

A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.

Real-world example

How this comes up in practice

A help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.

What to study next

Got this wrong? Here's your next step.

Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 220-1201 questions on switching, trunking, and access-port configuration.

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FAQ

Questions learners often ask

What does this 220-1201 question test?

Common Networking Hardware — This question tests Common Networking Hardware — Access ports place end devices into a single VLAN..

What is the correct answer to this question?

The correct answer is: The switch is power-cycling the phone due to PoE power budget constraints. — This question tests understanding of Power over Ethernet (PoE) power budgeting. When a PoE switch's power budget is near capacity, it may intermittently power down low-priority devices to prevent overload, causing the phone to reset or lose power. The correct answer is that the switch is power-cycling the phone due to power budget constraints.

What should I do if I get this 220-1201 question wrong?

Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 220-1201 questions on switching, trunking, and access-port configuration.

Are there clue words in this question I should notice?

Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

What is the key concept behind this question?

Access ports place end devices into a single VLAN.

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Last reviewed: Jun 18, 2026

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This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.