The SD-WAN Edge is the network function (physical or virtual) at the Service Provider side of the UNI reference point. It is part of the Service Provider Network, but it is commonly located at the Customer Premises when it is a physical network function. It is situated between the SD-WAN UNI, on its Subscriber side, and UCS UNIs of one or more Underlay Connectivity Services on its network side.
The SD-WAN Edge implements functionality that receives ingress IP Packets over the SD-WAN UNI; determines how they should be handled according to routing information, applicable policies, other service attributes, and information about the UCSs; and if appropriate, forwards them over one of the available UCS UNIs. Similarly, it receives packets over the UCS UNIs and determines how to handle them, including forwarding them on over the SD-WAN UNI if appropriate. The SD-WAN Edge thus implements all of the data plane functionality of the SD-WAN service that is not provided by a UCS. This includes routing functionality and the functionality associated with implementing the SWVC End Point.
Note that the SD-WAN Edge may also implement functionality that facilitates connection to the Underlay Connectivity Services. These functions are out of scope for the MEF 70 specification.