Which UCS type describes an underlay that traverses the public internet?

• A. Private UCS
• B. Flat Rate UCS
• C. Non Shared Underlay Transport
• D. Public UCS

Answer: (D)

In SD-WAN, the underlay is the transport network that carries the overlay tunnels between sites. A Public UCS specifically denotes an underlay that uses the public Internet as the path between locations, often with encryption and tunneling to secure and stabilize the traffic. This distinguishes it from a Private UCS, which relies on private, dedicated connectivity; Non Shared Underlay Transport, which concerns whether the underlay is shared among customers; and Flat Rate UCS, which is about pricing rather than the actual transport path. So, when the underlay traverses the public internet, Public UCS is the best fit.