Refer to the exhibit. Why does the end user complain of poor wireless performance?

Question

Exhibit

Options

• AChannel 48 utilization is at 84 percent.
• BNon-802.11 traffic of 18 percent indicates poor AP placement.
• CThe client is connected to the secondary radio of the AP instead of the primary radio
• DThe client is using a 20 MHz channel width to connect.

• A
  44% (26)
• B
  31% (18)
• C
  19% (11)
• D
  7% (4)

Explanation

Channel utilization at 84% means the wireless medium is nearly saturated - clients must wait significantly longer for airtime, causing latency spikes and reduced throughput. This is the direct cause of poor performance; most wireless best practices recommend keeping channel utilization below 70%.

Why the distractors are wrong:

• B - 18% non-802.11 interference is worth monitoring but is not alarmingly high, and interference percentage doesn't directly indicate poor AP placement. AP placement problems typically show up as weak signal (low RSSI), not interference percentages.
• C - Standard APs don't have a "primary" vs. "secondary" radio concept in the way described; this is a fabricated distractor. Radios are differentiated by band (2.4 GHz vs. 5 GHz), not primary/secondary.
• D - A 20 MHz channel width is perfectly valid and is actually preferred in dense environments to reduce co-channel interference. It reduces maximum throughput potential but doesn't inherently cause the kind of degradation seen here.

Memory tip: Think of channel utilization like a highway - at 84% capacity, traffic grinds to a crawl. The 70% rule is your trigger: anything above 70% utilization is a red flag on the wireless exam.

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