CWS Wi-Fi Service Sets Questions and Answers — Questions and Answers
Question 1: A company has deployed multiple access points across its large office building. All APs are configured with the same SSID, 'CorpNet', allowing employees to move between floors without losing their connection. From the perspective of the 802.11 standard, what is this entire network configuration called?
- Independent Basic Service Set (IBSS)
- Basic Service Set Identifier (BSSID)
- Extended Service Set (ESS) (Correct answer)
- Distribution System (DS)
Correct answer: Extended Service Set (ESS)
An Extended Service Set (ESS) is composed of two or more Basic Service Sets (BSSs) connected by a distribution system. This configuration allows multiple access points to use the same Service Set Identifier (SSID), enabling seamless roaming for clients within the coverage area.
Question 2: A user wants to quickly share a file with a colleague in a conference room where no pre-existing Wi-Fi network is available. They create a direct peer-to-peer wireless network between their two laptops. Which type of service set have they created?
- Extended Service Set (ESS)
- Basic Service Set (BSS)
- Mesh Basic Service Set (MBSS)
- Independent Basic Service Set (IBSS) (Correct answer)
Correct answer: Independent Basic Service Set (IBSS)
An Independent Basic Service Set (IBSS), also known as an ad-hoc network, allows wireless devices to communicate directly with each other without the need for a central access point. This is ideal for temporary, direct peer-to-peer connections.
Question 3: Which of the following uniquely identifies a Basic Service Set (BSS) and is typically the MAC address of the access point's radio?
- Service Set Identifier (SSID)
- Basic Service Set Identifier (BSSID) (Correct answer)
- Extended Service Set Identifier (ESSID)
- Station Identifier (STA ID)
Correct answer: Basic Service Set Identifier (BSSID)
The Basic Service Set Identifier (BSSID) is the unique, machine-readable identifier for a BSS. In an infrastructure BSS, this is the MAC address of the access point's wireless radio. While multiple APs in an ESS can share an SSID, each has a unique BSSID.
Question 4: A network technician is analyzing a wireless frame capture and observes traffic between several access points that share the same SSID. What logical component of the 802.11 architecture is responsible for interconnecting these Basic Service Sets (BSSs) to form an Extended Service Set (ESS)?
- Wireless Distribution System (WDS)
- Independent Basic Service Set (IBSS)
- Distribution System (DS) (Correct answer)
- Service Set Identifier (SSID)
Correct answer: Distribution System (DS)
The Distribution System (DS) is the architectural component in the IEEE 802.11 standard that connects multiple Basic Service Sets (BSSs) via their access points. This allows them to form a single logical network, known as an Extended Service Set (ESS), and facilitates frame forwarding between BSSs.
Question 5: In an infrastructure mode Basic Service Set (BSS), how do two client stations exchange data frames with each other?
- They send frames directly to each other after coordinating through the AP.
- All frames are sent to the Access Point (AP), which then forwards them to the destination station. (Correct answer)
- One station temporarily acts as an AP for the other station.
- They use the Distribution System Medium (DSM) to communicate directly.
Correct answer: All frames are sent to the Access Point (AP), which then forwards them to the destination station.
In an infrastructure BSS, client stations do not communicate directly. All data frames are sent from the source station to the access point. The AP then processes the frame and forwards it to the destination station within the same BSS. This centralized communication model is a key characteristic of infrastructure mode.
Question 6: Which statement accurately describes the relationship between an SSID and a BSSID in an Extended Service Set (ESS)?
- One SSID is mapped to one unique BSSID throughout the entire ESS.
- Each client device is assigned a unique BSSID, while the SSID is shared.
- One BSSID is used for the entire ESS, but each AP has a unique SSID.
- One SSID is shared among all APs, but each AP has a unique BSSID. (Correct answer)
Correct answer: One SSID is shared among all APs, but each AP has a unique BSSID.
In an ESS, the same Service Set Identifier (SSID), which is the human-readable network name, is used across all access points to facilitate seamless roaming. However, each individual access point (or more accurately, each radio within each AP) has its own unique Basic Service Set Identifier (BSSID), which is its MAC address.
CWS Wi-Fi Service Sets Questions and Answers
A company has deployed multiple access points across its large office building.
All APs are configured with the same SSID, 'CorpNet', allowing employees to move between floors without losing their connection.
From the perspective of the 802.11 standard, what is this entire network configuration called?