Which set of QoS mechanisms are typically used in MEF SD-WAN?

• A. Only rate limiting with no classification.
• B. Traffic classification, DSCP marking, queuing and scheduling (WFQ or priority), rate limiting, and dynamic path selection.
• C. Only routing decisions with no QoS.
• D. QoS is not used in MEF SD-WAN.

Answer: (B)

In MEF SD-WAN, QoS is achieved through a coordinated set of mechanisms that control how different traffic classes are treated across the WAN. This includes: traffic classification to identify which packets belong to which service or application; DSCP marking to signal priority levels end-to-end; queuing and scheduling (such as WFQ or priority queuing) to ensure higher-priority classes receive appropriate service; rate limiting to cap bandwidth usage per class and prevent congestion from starving other traffic; and dynamic path selection to route traffic over multiple links based on real-time performance and QoS needs. This combination lets the SD-WAN enforce service-level agreements and optimize performance for critical applications while efficiently using available link capacity.

Other options fall short because they address only a single aspect (like rate limiting alone or routing decisions without QoS) or claim QoS isn’t used, which isn’t accurate for MEF SD-WAN.