Software-defined Wide Area Network (SD-WAN) extends SDN practices to connect entities how?

• A. A type of local area network for enterprise campuses.
• B. An extension of the SDN practices to connect to entities spread across the internet to support WAN architecture especially related to cloud migration.
• C. A security protocol for isolating traffic in a data center.
• D. A hardware appliance for wide-area routing.

Answer: (B)

SD-WAN brings SDN thinking to the wide area by using a centralized controller and programmable edge devices to manage traffic across multiple transport options (internet, MPLS, wireless) and locations. It creates an overlay network with secure tunnels and application-aware routing, so branch offices, data centers, and cloud resources can be connected in a flexible, policy-driven way. This setup is especially useful for cloud migration, because traffic to SaaS and IaaS services can be guided along optimal paths regardless of the underlying transport, improving performance and reliability. The other descriptions don’t capture this broad, software-defined approach to connecting dispersed entities over the WAN.