Once an application is identified in SD-WAN, what routing decision is made?

• A. The end-user device's OS version.
• B. The route and QoS policy applied for the application.
• C. The cloud provider region used.
• D. The encryption algorithm used for the tunnel.

Answer: (B)

In SD-WAN, once the application is identified, the routing decision is to choose the path and apply the QoS policy for that application. The network uses the app’s signature to map its traffic to a specific set of rules that dictate which WAN link to use (the best path given current performance) and how to treat the traffic (priority, bandwidth guarantees, shaping). This is what ensures the application gets the appropriate performance, such as sending voice over the lowest-latency path with high priority, while less-sensitive traffic might ride a cheaper link with relaxed timing.

Other details like the end-user device’s OS version, the cloud provider region, or the encryption algorithm used for the tunnel aren’t the per-application routing decision. OS version isn’t a routing attribute, cloud region isn’t a per-app routing criterion, and encryption settings pertain to security of the tunnel rather than path selection or QoS for the application.