CWS CWS WLAN Roaming and QoS Questions and Answers 3

Question 1

Which 802.11 feature allows a client to request a neighbor report from its currently associated AP?

Accepted Answer

802.11k Neighbor Report Request

Answer

Under 802.11k, a client can send a Neighbor Report Request to its AP and receive a list of nearby APs to consider for roaming.

Question 2

What is the purpose of the AIFS (Arbitration Inter-Frame Space) in EDCA?

Accepted Answer

Defines the minimum idle time before a traffic category may begin contending for the channel

Answer

AIFS determines how long a station must sense the channel idle before beginning its random backoff, with higher-priority ACs using shorter AIFS values.

Question 3

In a 802.11r over-the-air fast transition, what frames does the client use to complete the roam?

Accepted Answer

Authentication and Reassociation frames with FT IEs

Answer

Over-the-air FT uses modified Authentication and Reassociation frames carrying FT Information Elements to complete the handoff with a single round-trip.

Question 4

Which AC_BK (Background) traffic characteristic distinguishes it from AC_BE (Best Effort)?

Accepted Answer

AC_BK uses a larger CWmin and longer AIFS, resulting in lower priority than AC_BE

Answer

AC_BK is configured with larger contention window parameters and a longer AIFS than AC_BE, making it the lowest-priority access category.

Question 5

What problem does load balancing address in a multi-AP WLAN deployment?

Accepted Answer

Prevents too many clients from associating with one AP while nearby APs are underutilized

Answer

Load balancing distributes client associations across APs to avoid overloading a single AP and ensure consistent throughput for all clients.

CWS Exam Practice Test

CWS Exam Practice Test

CWS CWS WLAN Roaming and QoS Questions and Answers 3