Network Arbitration and Contention JN0-452 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network administrator is analyzing a Wi-Fi network where two clients are repeatedly colliding. After each collision, the clients retransmit. The administrator wants to understand how the backoff timer changes after each failed transmission. Which statement correctly describes the backoff behavior after successive collisions?

   • AThe contention window doubles after each collision, up to a maximum value, and the backoff timer is randomly selected from the new window
   • BThe contention window is halved after each collision, and the backoff timer is selected from the smaller window
   • CThe contention window remains constant, but the backoff timer is decremented faster after each collision
   • DThe backoff timer is set to zero after each collision, allowing immediate retransmission
   Reveal Solution Discussion Select an answer first
2. 2foundation · easy

   How does frame aggregation reduce contention overhead in a Wi-Fi network?

   • ABy reducing the number of times stations must contend for the medium
   • BBy using a shorter interframe space for aggregated frames
   • CBy allowing stations to transmit without carrier sensing
   • DBy increasing the contention window for other stations
   Reveal Solution Discussion Select an answer first
4. 3foundation · easy

   Why does Wi-Fi use collision avoidance instead of collision detection?

   • ABecause wireless transceivers cannot listen for collisions while transmitting due to the half-duplex nature of the medium
   • BBecause collisions are harmless in wireless and do not corrupt data
   • CBecause the access point centrally manages all transmissions, eliminating the need for detection
   • DBecause wireless signals travel faster than wired signals, making detection impossible
   Reveal Solution Discussion Select an answer first
5. 4application · medium

   A network engineer is configuring QoS on an enterprise Wi-Fi network. Voice traffic is experiencing jitter because it is contending equally with bulk data transfers. The engineer decides to use EDCA to prioritize voice traffic. Which interframe space and contention parameter combination will give voice traffic the highest priority?

   • AAIFSN of 3 and a medium contention window
   • BAIFSN of 4 and a medium contention window
   • CAIFSN of 2 and a smaller contention window
   • DAIFSN of 7 and a larger contention window
   Reveal Solution Discussion Select an answer first
6. 5foundation · easy

   In the 802.11 random backoff algorithm, how is the initial backoff timer value selected?

   • AIt is set to a fixed value equal to the contention window minimum
   • BIt is randomly chosen from a range between zero and the current contention window size
   • CIt is assigned by the access point based on the station's traffic priority
   • DIt is determined by the number of retransmissions multiplied by a fixed slot time
   Reveal Solution Discussion Select an answer first