What does Quality of Service (QoS) primarily do in a network?

• A. Encrypt all payloads end-to-end
• B. Provide on-demand scaling of bandwidth
• C. Prioritize traffic and manage bandwidth
• D. Replace all routers with faster models

Answer: (C)

Quality of Service focuses on ensuring critical traffic gets priority and that bandwidth is managed to prevent congestion. In practice, devices classify and mark different types of traffic (such as voice, video, and standard data) and place them into appropriate queues, shape traffic, or police usage to guarantee lower latency and less jitter for time-sensitive applications. This approach helps ensure smooth voice calls and video streams even when the network is busy, by reserving or prioritizing the needed resources. It does not encrypt payloads, nor does it automatically scale total available bandwidth or require replacing hardware with faster models. QoS is about policy-driven control of traffic flow within existing network capacity to meet performance needs.