Software-defined wide-area networks (SD-WAN) is an approach to network connectivity that improves application performance, accelerates productivity and simplifies network management. SD-WAN uses virtualization technology to apply the benefits of software-defined networking to traditional router-centric, hardware-based networks to more intelligently direct traffic across a wide-area network (WAN).
Traditional WAN vs. SD-WAN
The purpose of a traditional WAN is to connect users in branch offices to applications hosted in on-premises data centers anytime, anywhere and from any device. This was achieved by directing traffic across routers, usually using a Multiprotocol Label Switching (MPLS) connection. Traffic was directed based on IP addresses and access control lists, with control functions distributed across all network routers.
Most apps are now hosted in the cloud due to the adoption of software-as-a-service (SaaS) and infrastructure-as-a-service (IaaS). Traditional WAN architectures can’t efficiently handle this influx of cloud traffic.
This created a need to find new methods for directing traffic, as sending cloud traffic to an on-premises data center before being sent to the internet results in latency, degraded application performance, costly bandwidth and security vulnerabilities. SD-WAN is application-aware, so it directs traffic across the network based on business requirements for applications, such as priority, performance and security policies.
SD-WAN is able to host applications on all platforms, including on-premises data centers, branch offices and public or private clouds. It can also leverage any combination of transport services, including MPLS, broadband internet and 4G/5G LTE.
Improved performance and productivity
More efficient traffic directing means improved application performance. High availability with predictable service means teams are able to be more agile with their workflows. This leads to a better user experience, and ultimately, improved productivity.
SD-WAN decouples the networking hardware, or the data forwarding plane, from the control function to simplify management and operations. A single, centralized dashboard makes it easy to configure and manage the WAN. Policies that govern how applications are delivered to users are defined centrally and assigned automatically across potentially thousands of SD-WAN appliances connected to a network. Admins can also pull reports on application and WAN performance.