ABC Company has a 2.4 and 5 GHz WLAN deployment supporting four bands in the 5 GHz range
(UNII 1, UNII 2, UNII 2e, and UNII 3). DFS functionality is enabled as required by the regulatory
domain. Band steering is also enabled to encourage dual-band clients to use frequency bands
with more capacity.
Your performance analysis shows that many dual-band VoWiFi client devices will move back and
forth between 2.4 and 5 GHz as the user roams throughout the building. All APs have 2.4 and 5
GHz radios enabled.
This “band hopping” behavior is viewed by network staff to be undesirable. What is the most likely
cause of the unpredictable client band selection behavior?

A.
Interference from 5 GHz radar sources has increased frame corruption and retries on channels
36-48 in UNII 1.

B.
5 GHz frequencies offer better RF penetration than 2.4 GHz, but 2.4 GHz offers more voice call
capacity and lower latency than 5 GHz.

C.
The voice client does not support DFS, and therefore experiences some 5 GHz coverage holes
as it moves through the network.

D.
The client’s band selection algorithm prefers 5 GHz, but band steering behavior usually steers
75-85% of client devices to 2.4 GHz.