Which overlay transport protocol carries encrypted control and data traffic between WAN Edge devices?

Which overlay transport protocol carries encrypted control and data traffic between WAN Edge devices?

• A. DTLS/TLS
• B. CAPWAP
• C. STP
• D. SNMP

Answer: (A)

The overlay transport protocol used to carry encrypted control and data traffic between WAN Edge devices is DTLS/TLS. In SD-WAN, the overlay tunnel must secure both control-plane messages (routing, signaling, policy) and data-plane traffic. TLS provides mutual authentication and encryption for control communications, while DTLS brings the same security to datagram (UDP) traffic, which many overlays use for efficiency and NAT traversal. This setup ensures confidentiality, integrity, and authenticity across the entire overlay between WAN Edges. The other options aren’t suited for this role: CAPWAP is for wireless AP management, STP is a layer 2 loop-prevention protocol, and SNMP is a management protocol.

The overlay transport protocol used to carry encrypted control and data traffic between WAN Edge devices is DTLS/TLS. In SD-WAN, the overlay tunnel must secure both control-plane messages (routing, signaling, policy) and data-plane traffic. TLS provides mutual authentication and encryption for control communications, while DTLS brings the same security to datagram (UDP) traffic, which many overlays use for efficiency and NAT traversal. This setup ensures confidentiality, integrity, and authenticity across the entire overlay between WAN Edges. The other options aren’t suited for this role: CAPWAP is for wireless AP management, STP is a layer 2 loop-prevention protocol, and SNMP is a management protocol.