CWDP CWDP Roaming and Client Mobility

Question 1

Which IEEE amendment defines fast BSS transition (FT), reducing roaming latency for real-time applications?

Accepted Answer

IEEE 802.11r

Answer

IEEE 802.11r defines Fast BSS Transition, enabling pre-authentication with target APs to reduce handoff time below 50 ms.

Question 2

What problem does IEEE 802.11k (Radio Resource Management) solve in roaming scenarios?

Accepted Answer

Provides clients with neighbor AP reports to accelerate target AP discovery

Answer

802.11k neighbor reports give clients a pre-built list of APs to consider for roaming, eliminating time-consuming full channel scans.

Question 3

What is 'sticky client' behavior and why is it problematic in enterprise WLAN design?

Accepted Answer

Clients that maintain association with a distant AP despite a closer one being available

Answer

Sticky clients stay connected to a far AP with weak RSSI rather than roaming to a closer one, degrading throughput and reliability.

Question 4

In the 802.11r fast transition process, what is the role of the 'R0 Key Holder'?

Accepted Answer

The first AP in the mobility domain that derives the master session key

Answer

The R0 Key Holder (typically the original authenticating AP or controller) holds the top-level PMK-R0 from which all roaming keys are derived.

Question 5

What IEEE amendment enables BSS Transition Management, allowing APs to suggest better APs to clients?

Accepted Answer

802.11v

Answer

802.11v BSS Transition Management allows APs to send BTM Request frames suggesting clients move to a better AP.

Certified Wireless Design Professional (CWDP) Practice Test