CWNA Quality Control & Assurance 5

Question 1

A network administrator uses 802.11k to improve WLAN quality. Which specific capability does 802.11k provide to clients?

Accepted Answer

Neighbor reports that help clients identify candidate APs for roaming without active scanning

Answer

Faster four-way handshake key caching during roaming

Answer

Automatic channel selection based on interference levels

Answer

Compressed block acknowledgment for high-throughput data streams

Question 2

An enterprise deploys 802.11ac Wave 2 APs with MU-MIMO. Which condition MUST be met for MU-MIMO to deliver a quality improvement over SU-MIMO?

Accepted Answer

Multiple clients must simultaneously have data to receive and support MU-MIMO

Answer

All clients must be connected on the same channel width

Answer

APs must be configured with WPA3 encryption

Answer

Clients must support 802.11r fast roaming

Question 3

A WLAN QA process includes validating the CCI (Co-Channel Interference) design. What is the standard recommended minimum cell overlap for proper roaming while minimizing CCI?

Accepted Answer

15–20% cell overlap between adjacent same-channel APs

Answer

50% cell overlap to ensure seamless roaming

Answer

0% overlap so each AP has an exclusive coverage zone

Answer

35–40% overlap regardless of channel reuse plan

Question 4

Which metric directly quantifies the effect of multipath propagation on WLAN quality in an indoor environment?

Accepted Answer

Delay spread (RMS delay spread)

Answer

EIRP (Effective Isotropic Radiated Power)

Answer

DTIM interval

Answer

Association timeout value

Question 5

During a QA review, an administrator finds that 40 MHz channels are configured in the 2.4 GHz band. Why is this considered poor practice?

Accepted Answer

40 MHz channels consume most of the 2.4 GHz band, leaving no non-overlapping channels and increasing interference

Answer

40 MHz channels are not supported by 802.11n in the 2.4 GHz band

Answer

40 MHz channels reduce beamforming effectiveness at 2.4 GHz

Answer

40 MHz channels double the beacon interval, slowing discovery

Question 6

A QA engineer validates that an AP is correctly implementing TXOP (Transmission Opportunity) limits. What is the primary purpose of TXOP limits in WMM?

Accepted Answer

To cap how long a station can occupy the medium per burst, preventing one AC from starving others

Answer

To increase the maximum frame size for high-priority traffic

Answer

To reduce the SIFS interval for voice traffic

Answer

To disable acknowledgments for broadcast frames

Question 7

Which approach is BEST for validating WLAN performance under realistic load conditions before a production cutover?

Accepted Answer

Load testing with traffic generation tools that simulate expected concurrent client sessions

Answer

Reviewing AP vendor datasheets for maximum throughput specifications

Answer

Checking SNMP counters from a single client association

Answer

Running a passive site survey with no client traffic