Computer Networks — Test 23

Correct Answer: A. A. Multiple access point are inter-connected with each other
Explanation: A Wireless Distribution System allows the connection of multiple access points together. It is used to expand a wireless network to a larger network.

Correct Answer: C. C. Both infrastructure mode and ad-hoc mode
Explanation: A wireless network interface controller works on the physical layer and the data link layer of the OSI model. Infrastructure mode WNIC needs access point but in ad-hoc mode access point is not required.

Correct Answer: A. A. Connected basic service sets
Explanation: The extended service set is a part of the IEEE 802.11 WLAN architecture and is used to expand the range of the basic service set by allowing connection of multiple basic service sets.

Correct Answer: B. B. Orthogonal frequency division multiplexing
Explanation: In orthogonal frequency division multiplexing, digital data is encoded on multiple carrier frequencies. It is also used in digital television and audio broadcasting in addition to Wireless LANs.

Correct Answer: A. A. Collision detection
Explanation: Collision detection is not possible in wireless LAN with no extensions. Collision detection techniques for multiple access like CSMA/CD are used to detect collisions in Wireless LANs.

Correct Answer: B. B. Security algorithm for wireless networks
Explanation: WEP is a security algorithm for wireless network which intended to provide data confidentiality comparable to that of traditional wired networks. It was introduced in 1997.

Correct Answer: A. A. Wi-fi protected access
Explanation: WPA or WiFi Protected Access is a security protocol used to provide users and firms with strong data security and protection for their wireless networks (WiFi) to give them confidence that only authorized users can access their network.

Correct Answer: D. D. All of the mentioned
Explanation: PING (Packet Internet Groper) command is the best way to test connectivity between two nodes, whether it is Local Area Network (LAN) or Wide Area Network (WAN). Ping uses ICMP (Internet Control Message Protocol) to communicate to other devices.

Correct Answer: B. B. Nmap
Explanation: A ping sweep is a method that can establish a range of IP addresses which map to live hosts and are mostly used by network scanning tools like nmap. A ping sweep is basically a collective ping command execution on a range of IP addresses.

Correct Answer: D. D. Both ping & traceroute
Explanation: ICMP stands for Internet Control Message Protocol. ICMP operates over the IP packet to provide error reporting functionality, so in case the node is not active or there is no route, ICMP will be used to report the specific errors for Ping and Traceroute.