CWS CWS Wi-Fi Service Sets 2 — Questions and Answers
Question 1: What identifier uniquely distinguishes one BSS from another at Layer 2?
- SSID
- BSSID (Correct answer)
- ESSID
- HESSID
Correct answer: BSSID
The BSSID is a 48-bit MAC address that uniquely identifies a single BSS at Layer 2.
Question 2: In an IBSS (ad-hoc) network, which device generates the BSSID?
- The DHCP server
- The first station that starts the IBSS (Correct answer)
- The nearest AP
- A central controller
Correct answer: The first station that starts the IBSS
In an IBSS, the first station that beacons and establishes the network generates a locally administered BSSID.
Question 3: Which statement correctly describes a Distribution System (DS) in a Wi-Fi ESS?
- It is the wireless medium between client and AP
- It is the wired or logical backbone interconnecting APs (Correct answer)
- It is the encryption layer between BSSes
- It is a dedicated AP that bridges two SSIDs
Correct answer: It is the wired or logical backbone interconnecting APs
The Distribution System (DS) is the wired or logical infrastructure (typically Ethernet) that connects multiple APs to form an ESS.
Question 4: A roaming client moves from AP1 to AP2, both sharing the same SSID. What remains constant during this transition?
- BSSID
- SSID (Correct answer)
- Channel
- Transmit power
Correct answer: SSID
The SSID (network name) stays the same across all APs in an ESS, enabling seamless roaming without reconfiguration.
Question 5: How many BSSes can share the same SSID to form an ESS?
- Exactly 2
- Up to 16
- Up to 32
- No fixed limit—two or more (Correct answer)
Correct answer: No fixed limit—two or more
An ESS can consist of two or more BSSes (with no fixed upper limit) that share the same SSID and are connected through a DS.
Question 6: What term describes the physical coverage area provided by a single AP's radio?
- ESA
- DS
- BSA (Correct answer)
- IBSS zone
Correct answer: BSA
The Basic Service Area (BSA) is the geographic RF coverage zone of a single AP or BSS.
Question 7: Which service set type is most appropriate for a temporary peer-to-peer file transfer between two laptops with no infrastructure available?
- BSS
- ESS
- IBSS (Correct answer)
- MBSS
Correct answer: IBSS
An IBSS (Independent Basic Service Set), also called ad-hoc mode, allows direct peer-to-peer communication without an AP.
CWS CWS Wi-Fi Service Sets 2
What identifier uniquely distinguishes one BSS from another at Layer 2?