Which combination of features mitigates packet loss in SD-WAN?

• A. Redundant single path, static routing, and encryption only
• B. Multi-path redundancy, adaptive QoS, and error concealment
• C. Single tunnel with high bandwidth
• D. Offloading to VPN only

Answer: (B)

Mitigating packet loss in SD-WAN relies on combining resilience with real-time traffic control and recovery techniques. Using multiple WAN paths (multi-path redundancy) allows traffic to be sent over several links and quickly reroute around a failing or congested path, reducing the impact of any single path's loss. Adaptive QoS dynamically prioritizes latency-sensitive and critical applications, adjusts queues, and shapes traffic to keep important flows from dropping packets during congestion. Error concealment helps recover or mask lost data at the receiving end, using techniques like forward error correction or interpolation to minimize perceptible disruption, especially for real-time traffic.

Relying on a redundant single path with static routing lacks the flexibility to adapt to changing conditions, a single high-bandwidth tunnel can still lose packets under congestion, and offloading only to VPN doesn’t address loss control or recovery. The combination of multiple paths, adaptive QoS, and error concealment provides comprehensive mitigation against packet loss in SD-WAN.