Which term denotes the physical network function in SD-WAN architecture?

• A. VNF
• B. TVC
• C. UNI
• D. PNF

Answer: (D)

The idea being tested is the distinction between physical versus virtual network functions in SD-WAN. A physical network function is the actual hardware appliance that performs the networking tasks at branches or data centers. In SD-WAN, these hardware devices handle tasks like routing, VPN termination, firewall, and policy enforcement as a tangible, dedicated unit. That’s why the term for the physical network function is PNF.

In contrast, a virtual network function represents the same capabilities delivered as software running on virtualized or cloud infrastructure, which provides flexibility and easier scaling. The other terms aren’t about a physical device: UNI refers to the user–network interface, and TVC isn’t the standard designation for a physical network function in SD-WAN.