Cisco SD-WAN controllers are software images customers download from Cisco’s website using their Smart Account. There are no hardware appliances for any of the controllers , and according to Cisco, there will never be one. The fact that the Manager/Validator/Controller are software devices is a huge advantage that allows organizations to deploy the controllers in a public or private cloud. This can significantly reduce the CAPEX/OPEX costs and improve the overall availability and redundancy of the management, orchestration, and control planes.