SD-WAN, or software-defined wide area network, is a wide area network that uses software to control network operations across different geographies. SD-WAN is the next evolutionary step from a traditional WAN network which connects local area networks (LANs) together using VPNs or routers and un on MPLS.
WANs support a traditional client-server model where applications live in on-site data centers but are not designed to support applications hosted in the cloud. WAN networks run over MPLS and cannot directly access cloud resources from the branch but instead follow a hub and spoke design that backhauls traffic through the corporate data center. An SD-WAN extends support and visibility from the enterprise, branch and corporate data center into cloud-based applications allowing remote workers to experience high-performance levels.
SD-WAN allows WANs to mix and match different transport layers like broadband, 4G, or LTE, instead of only MPLS.
Moves, adds, and changes can happen on demand without significant preplanning or deployment periods. SD-WAN makes change management much more agile with its scalability of resources. Network changes can be made in a matter of clicks instead of stretching out over weeks and involving multiple parties.
Bandwidth is pooled from different service providers, so prioritization of specific applications can automatically run on the least congested links – the applications are not tied to underlying transport types but can take the fastest path intelligently for optimized performance. This results in fewer QoS policy violations and mitigates network congestion.