Note that in Figure 1 one of the Subscriber sites is connected to a Private or Virtual Private Cloud which may not be located at the Subscriber’s physical location. This type of connection operates no differently in the SD-WAN Service than any of the other Subscriber Network locations although for the cloud connection the SD-WAN Edge is usually a virtual network function (VNF), whereas for the other sites the SD-WAN Edge could be either a physical network function (PNF) or a VNF.
Two additional components, the Tunnel Virtual Connection (TVC) and the SD-WAN Edge, are also described since these components are used to describe the operation of the SD-WAN Service. These components are shown in Figure 2 (the SD-WAN Edge is also shown in Figure 1).
Figure 2 – SD-WAN Edge and TVCs
Figure 2 shows the SD-WAN Edge, a physical or virtual network function, which includes the SWVC End Point. The SD-WAN Edge has the UNI on one side (left) and the Underlay Connectivity Services on the other side (right).
Figure 2 also shows TVCs across the Underlay Connectivity Services. TVCs or Tunnel Virtual Connections are point-to-point paths across the Underlay Connectivity Services that define the logical forwarding topology of the SD-WAN Service.