Which term is the virtual path used for underlay connectivity, with SD-WAN Edge routing based on these?

• A. SWVC
• B. PVC
• C. TVC
• D. UNI

Answer: (C)

Transport Virtual Circuit is the virtual path that carries the underlay connectivity in SD-WAN. It represents the dedicated, carrier-provisioned transport path that connects SD-WAN Edge devices across the underlying network (MPLS, Internet, etc.). The SD-WAN overlay runs on top of this TVC, using it as the stable transport layer while applying its own routing, policies, and encryption above it.

Other terms don’t fit this role: a Permanent Virtual Circuit is an older Frame Relay concept for a pre-established link, not the modern SD-WAN underlay path; the User-Network Interface is simply the boundary between customer and provider networks; and SWVC is not the standard term used for the SD-WAN underlay transport path.