CWS CWS Wi-Fi Service Sets 5

Question 1

Which IEEE amendment introduced the Mesh Basic Service Set (MBSS) and mesh networking standards?

Accepted Answer

802.11s

Answer

IEEE 802.11s introduced the MBSS, defining how mesh points (MPs) discover each other and route frames over multi-hop wireless links.

Question 2

What is the key characteristic that distinguishes a BSS from an IBSS?

Accepted Answer

BSS uses an AP as the central coordinator; IBSS has no AP

Answer

A BSS (infrastructure mode) requires an AP to coordinate all communications, while an IBSS (ad-hoc mode) has no AP and stations communicate directly.

Question 3

When a roaming client re-associates from one AP to another within the same ESS, which parameter must remain the same for the roam to succeed transparently?

Accepted Answer

Security cipher suite and SSID

Answer

For a successful roam within an ESS, both the SSID and the security/encryption parameters must match across APs, while the BSSID will differ.

Question 4

What does it mean when an AP advertises multiple BSSIDs from the same physical radio?

Accepted Answer

The AP is supporting multiple SSIDs, each with its own virtual BSS

Answer

When an AP supports multiple SSIDs, it creates a virtual BSS for each SSID, each with a unique BSSID derived from the AP's base MAC address.

Question 5

An 802.11 client in power-save mode relies on which beacon-carried information to know when buffered frames await pickup?

Accepted Answer

TIM (Traffic Indication Map)

Answer

The Traffic Indication Map (TIM) in the beacon informs power-saving clients which of them have frames buffered at the AP awaiting retrieval.

CWS Exam Practice Test

CWS Exam Practice Test

CWS CWS Wi-Fi Service Sets 5