What is the purpose of TVC in SD-WAN connectivity?

• A. It provides a point-to-point path between two nodes across the network
• B. It creates a shared broadcast domain
• C. It is a type of VPN
• D. It is a DNS service

Answer: (A)

The idea behind TVC is to establish a dedicated transport path that directly connects two SD-WAN edge nodes across the service provider network. This Transport Virtual Circuit creates a single, point-to-point, logical path that abstracts the variety of underlying physical links (different ISPs, multiple paths) into one predictable conduit. With this circuit in place, the SD-WAN can enforce consistent performance characteristics, such as bandwidth and latency, and route traffic across a defined route, while the overlay policies and tunnels handle the actual application-level connectivity on top of this transport.

This isn’t about creating a shared broadcast domain, which would mix traffic in a way that isn’t inherently isolation-based or path-specific. It’s not simply a type of VPN, though the SD-WAN overlay VPNs ride over the TVC. And it isn’t a DNS service. The TVC’s purpose is the dedicated, point-to-point transport path that underpins the SD-WAN connectivity.