SD-WAN Architecture
The Evolution of the Enterprise Edge
From MPLS to SD-WAN
Traditional wide area networks (WANs) relied on expensive, rigid MPLS circuits. Software-Defined WAN (SD-WAN) decouples the network software from the underlying hardware, allowing companies to use a mix of broadband, 5G, and MPLS simultaneously while managing them centrally.
The Two-Plane Separation
A core principle of SD-WAN is the separation of the Control Plane (brains) from the Data Plane (brawn).
- Central Orchestration: A central controller pushes policy to all edge nodes.
- Dynamic Path Selection: The edge node monitors RTT, jitter, and loss on all active circuits and steers traffic to the best available path in real-time.
SD-WAN Engine: Dynamic Steering
Simulate link failures and watch real-time path steering.
Link Performance MTTR
Application Policy Engine
Orchestration Decision Log
> INFO: All transport links healthy. Routing critical apps via low-latency MPLS backbone.
Application-Aware Routing
SD-WAN doesn't just route IPs; it routes applications.
SLA-Based Steering
Policy Example: "If Office 365 traffic experiences latency on ISP A, move it instantly to ISP B."
Conclusion
SD-WAN has transformed the ROI for corporate networking, allowing branch offices to achieve high-availability performance using consumer-grade internet circuits through intelligent orchestration.