Cisco SD-WAN builds on this well-known idea of the overlay network and takes it much further. It does not just create dynamic IPsec tunnels across the underlay. It adds multiple layers of improvement that make the WAN easier to operate, scale, secure, and automate.
It achieves these benefits by combining proven networking technologies with newer and more innovative techniques. These can be summarized into six fundamental principles:
- Principle#1: Separating transport from the service side of the network.
- Principle#2: Separating control, data, and management planes.
- Principle#3: Establishing an overlay fabric.
- Principle#4: Managing the fabric as-a-system using centralized policies.
- Principle#5: Distributing security capabilities into edge devices.
- Principle#6: Simplifying onboarding and orchestrating of new devices.
Let’s now look at each of these principles one by one and see how each of them improves the basic overlay model. As you move through them, you will notice that Cisco SD-WAN is not just another overlay technology. It extends the idea with features that make the WAN better suited for modern enterprise networks.