How does application identification occur in SD-WAN?

• A. DNS-based only.
• B. Through DPI or signature-based methods, port-based classification, and policy-based rules to identify applications for routing and QoS decisions.
• C. It uses static port numbers only.
• D. It ignores application identities for QoS.

Answer: (B)

Application identification in SD-WAN uses a layered approach that combines multiple techniques to recognize traffic accurately and apply appropriate handling. Deep packet inspection looks into the payload to identify apps even when ports are altered, while signature-based methods match known application patterns. Port-based classification can help when apps use standard ports, but it isn’t reliable on its own because ports can be changed or spoofed. Policy-based rules let administrators explicitly classify traffic according to business needs, ensuring consistent handling even if detection isn’t perfect. Once an application is identified, SD-WAN can route it along the best path and enforce QoS and security policies accordingly. DNS-based-only identification or reliance on static ports alone would be insufficient, and ignoring application identities would remove the essential capability to tailor routing and QoS.