300-415 Question 275
Single answerAn enterprise is using Cisco SD-WAN to optimize its WAN traffic. The network administrator configures per-tunnel QoS policies to ensure critical applications like voice and video have priority. However, users report degraded performance during periods of high congestion. To address this issue, the administrator decides to implement adaptive QoS. How does adaptive QoS improve application performance in this scenario?
- A
It dynamically adjusts the tunnel bandwidth based on real-time link conditions and application requirements.
- B
It enforces static bandwidth policies to ensure consistent performance for critical applications.
- C
It prioritizes traffic only for applications explicitly marked by the administrator in the configuration.
- D
It uses application-aware routing to steer traffic to the least congested path without considering QoS markings.
Show answer and explanation
Correct answer: A
Explanation
In Cisco SD-WAN, adaptive QoS enhances application performance by dynamically adjusting tunnel bandwidth based on real-time network conditions and application requirements. This is especially beneficial during periods of high congestion, as it ensures critical applications like voice and video receive the necessary resources to maintain performance. Static policies or simple traffic steering are insufficient for handling dynamic network conditions effectively.
- A. Correct.
Adaptive QoS dynamically adjusts tunnel bandwidth based on real-time link conditions, such as latency, jitter, and loss, as well as application requirements. This ensures critical applications get the resources they need during congestion.
- B. Incorrect.
Static bandwidth policies do not account for real-time changes in network conditions, which can lead to suboptimal performance during periods of high congestion.
- C. Incorrect.
While application marking is part of QoS, adaptive QoS goes beyond static configurations and dynamically adjusts resources based on real-time conditions.
- D. Incorrect.
Application-aware routing is a separate feature that steers traffic based on path performance metrics. However, it does not directly manage bandwidth or prioritize traffic within a tunnel based on QoS policies.