CWS WLAN Roaming and QoS Questions and Answers Flashcards

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

Answer: 802.11k Neighbor Report Request

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.

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

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

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

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

Answer: Authentication and Reassociation frames with FT IEs

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

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

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

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

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

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

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

Which protocol is used by a WLAN controller to request that a client roam to a different AP under 802.11v?

Answer: BSS Transition Management Request

The BSS Transition Management Request frame (802.11v) is sent by the AP/controller to suggest or require a client to roam to a specified target AP.