SD-WAN

SD-WAN is an acronym for software-defined networking in a wide area network (WAN). SD-WAN simplifies the management and operation of a WAN by decoupling (separating) the networking hardware from its control mechanism. This concept is similar to how software-defined networking implements virtualization technology to improve data center management and operation. SD-WAN is an acronym for software-defined networking in a wide area network (WAN). SD-WAN simplifies the management and operation of a WAN by decoupling (separating) the networking hardware from its control mechanism. This concept is similar to how software-defined networking implements virtualization technology to improve data center management and operation. A key application of SD-WAN is to allow companies to build higher-performance WANs using lower-cost and commercially available Internet access, enabling businesses to partially or wholly replace more expensive private WAN connection technologies such as MPLS. American marketing research firm Gartner predicted in 2018 that by 2023 more than 90 percent of WAN edge infrastructure refresh initiatives will be based on virtualized customer premises equipment (vCPE) platforms or SD-WAN software/appliances. WANs allow companies to extend their computer networks over large distances, to connect remote branch offices to data centers and each other, and deliver the applications and services required to perform business functions. When companies extend networks over greater distances and sometimes across multiple carriers' networks, they face operational challenges including network congestion, packet delay variation, packet loss, and even service outages. Modern applications such as VoIP calling, videoconferencing, streaming media, and virtualized applications and desktops require low latency. Bandwidth requirements are also increasing, especially for applications featuring high-definition video. It can be expensive and difficult to expand WAN capability, with corresponding difficulties related to network management and troubleshooting. SD-WAN products are designed to address these network problems. By enhancing or even replacing traditional branch routers with virtualization appliances that can control application-level policies and offer a network overlay, less expensive consumer-grade Internet links can act more like a dedicated circuit. This simplifies the setup process for branch personnel. SD-WAN products can be physical appliances or virtual appliances, and are placed in small remote and branch offices, larger offices, corporate data centers, and increasingly on cloud platforms. A centralized controller is used to set policies and prioritize traffic. The SD-WAN takes into account these policies and the availability of network bandwidth to route traffic. This helps ensure that application performance meets service level agreements (SLAs). SD-WAN consists of several technologies combined with newer enhancements. Redundant telecommunication links connecting remote sites date back to the 1970s with X.25 links used for remote mainframe terminal access. Central management of those links with a greater focus on application delivery across the WAN started to become popular in the mid-2000s. SD-WAN combines the two, and adds the ability to dynamically share network bandwidth across the connection points. Additional enhancements include central controllers, zero-touch provisioning, integrated analytics and on-demand circuit provisioning, with some network intelligence based in the cloud, allowing centralized policy management and security. Networking publications started using the term SD-WAN to describe this new networking trend as early as 2014. Research firm Gartner has defined an SD-WAN as having four required characteristics: