SD-WAN - vSmart
vSmart is the control plane of the architecture. vSmart controllers advertise routes, security, and policy information. Cisco SD-WAN uses the proprietary Overlay Management Protocol (OMP) for this. vSmart implements the policies that you configure through vManage.
For example, imagine you create a policy through vManage where real-time voice traffic requires a latency of less than 100 ms. The vSmart controller downloads the policy, converts it into a format suitable for the vEdge routers and then implements it on all vEdge routers.
All vEdge routers peer with a vSmart controller, it’s a hub and spoke topology. It’s similar to a BGP Route Reflectoror a DMVPN NHRP server. The vSmart controller only lives in the control plane and is never in the data plane.