📝 Data flow characteristics in QoS (9 MCQs)
📖 From Data Communication and Networks • 30. Quality of Service • 9 questions available
What is Data flow characteristics in QoS?
Data flow characteristics refer to the specific measurable attributes of network traffic, such as reliability, delay, jitter, and bandwidth, that determine how well a particular application performs and what quality of service guarantees it requires from the network.
📝 All Data flow characteristics in QoS MCQs
Q1. An application that requires low jitter will be most affected by which data‑flow characteristic?
📖 Explanation: Jitter quantifies the variation in packet arrival times. An application that is sensitive to jitter will experience degraded performance when jitter is high, because timing irregularities disrupt synchronization. Therefore, among the listed characteristics, high jitter is the factor that most directly affects such an application, making option C correct.
Q2. Which statement correctly compares a video‑conferencing service and a file‑transfer service regarding reliability and bandwidth requirements?
📖 Explanation: Video‑conferencing requires a continuous, real‑time audio/video stream, so any lost or delayed packet can be noticeable, demanding very high reliability. However, the amount of data transmitted per second is typically lower than that of bulk file transfers, which can use large bandwidth but tolerate retransmissions. Consequently, video‑conferencing needs higher reliability and lower bandwidth compared with file‑transfer, confirming option A.
Q3. If a streaming service must guarantee a maximum end‑to‑end delay of ms and jitter below ms, which combination of network features should be prioritized?
📖 Explanation: To meet a strict end‑to‑end delay ceiling of ms and keep jitter under ms, the network must minimize propagation and processing delays while smoothing packet timing. Path optimization reduces travel time, and jitter buffers absorb timing variations, ensuring consistent arrival. Bandwidth increase alone does not address delay or jitter, so the combination described in option A is the most appropriate.
Q4. Real‑time online gaming is highly sensitive to delay. If the network delay doubles, what is the most likely impact on player experience?
📖 Explanation: Doubling the network delay adds a proportional increase to the time it takes for a player's input to reach the game server and for the resulting state to be reflected back. This additional latency manifests as noticeable lag, reducing the responsiveness of controls and overall interactivity, which degrades the gaming experience. Therefore, the most likely impact is increased response lag and reduced interactivity, as stated in option D.
Q5. A telemedicine application requires 99.999% reliability and 5 Mbps bandwidth. Which trade‑off is most appropriate if the available link can only provide 3 Mbps with 99.99% reliability?
📖 Explanation: The telemedicine system requires near‑perfect reliability (99.999 %) and a bandwidth of 5 Mbps to transmit high‑resolution video and patient data. When only a 3 Mbps link with 99.99 % reliability is available, the most viable compromise is to lower the video resolution, thereby reducing the bandwidth demand while preserving the high reliability needed for critical information. Option D reflects this balanced approach.
Q6. Design a network scenario that simultaneously satisfies low delay ( ms), low jitter ( ms), high reliability (99.999%), and moderate bandwidth (2 Mbps) for a control‑system application. Which architecture best meets these needs?
📖 Explanation: A dedicated fiber optic link can provide deterministic low propagation delay and minimal jitter, essential for the sub‑50 ms and sub‑10 ms limits. Implementing Quality‑of‑Service (QoS) prioritization guarantees that control‑system packets receive preferential treatment, while redundant paths ensure the 99.999 % reliability requirement is met even if a segment fails. This combination satisfies all specified constraints, making option D the optimal choice.
Q7. What does the term 'jitter' refer to in data‑flow characteristics?
📖 Explanation: Jitter describes the variability in the timing between successive packet arrivals at a receiver. In networking, it quantifies how much the inter‑arrival time deviates from a steady interval, which can affect applications that rely on consistent timing, such as voice over IP or streaming media. Therefore, the correct definition is the variation in packet arrival time, corresponding to option C.
Q8. If packet loss increases, which data‑flow characteristic is most directly compromised?
📖 Explanation: Reliability measures the probability that data packets are delivered without error. An increase in packet loss directly reduces this probability, meaning fewer packets reach their destination intact. While loss can also affect delay and jitter indirectly, the most immediate and direct impact is on reliability. Hence, option C correctly identifies reliability as the characteristic most compromised by rising packet loss.
Q9. How does bursty traffic differ from constant‑bit‑rate traffic in terms of bandwidth utilization?
📖 Explanation: Bursty traffic consists of short intervals where data rates surge well above the average, creating temporary peaks that can exceed the capacity of a link if it is not sized for those spikes. To accommodate such variability, network designers often provision additional bandwidth beyond the average demand. This behavior matches option A, which states that bursty traffic can cause temporary bandwidth spikes requiring over‑provisioning.