In a nutshell, SD-WAN
- Virtualizes the network
- Enables a secure overlay
- Simplifies services delivery
- Provides interoperability
- Leverages cost effective hardware
- Supports automation with business policy framework
- Monitors usage and performance
- Supports interoperable and open networking
- Enables managed services
SD‐WAN as a network overlay enables application traffic to be carried independently of the underlying physical or transport layer, offering a transport‐independent overlay. Multiple links, even from different service providers, constitute a unified pool of resources, often referred to as a virtual WAN.
This capability enables SD‐WAN to provide high availability and performance for applications. It also increases the utilization of resources and simplifies the network.
SD-WAN 能够对底层物理传输层进行抽象，对各种各样的物理链路进行整合统一，为应用程序提供高可用和高性能的虚拟 WAN 服务。
Network operators can add new links and applications easily because no static tie exists between the application and the link it must use – a key benefit of the abstraction principle. The virtualization also provides self‐healing as links experience degraded performance.