How does SD-WAN work?

- Dec 03, 2020-

SD-WAN (Software-Defined Wide Area Network), is a service formed by applying SDN technology to a wide area network scenario. This service is used to connect a wide geographic range of enterprise networks, data centers, Internet applications, and cloud services.

The typical feature of this kind of service is to ‘cloudize’ network control capabilities through software and support application-aware network capabilities opening

SD-WAN represents the most interesting application of SDN technology in 2015. It aims to help users reduce wide area network (WAN) expenses and increase network connection flexibility. According to surveys, despite the large number of new and old suppliers entering the market, judging from the actual deployment in 2015, the actual landing projects are still very limited. But SD-WAN is not just a buzzword, it is already bringing benefits to early deployers. 

From 2006 when Stanford University proposed the centralized control architecture and Openflow protocol, to the commercial case of Google B4 in 2012, the focus of SDN's budding and disillusionment period has always been in the cloud and data center scenarios. The industry urgently needs to find the next killer app . On the other hand, the development of cloud computing technology has triggered the transformation of the IT industry. Internet + has driven the transformation of traditional industries. The Internetization of to B surpassed the attention of to C in 2014. It can be said that SD-WAN services focused on the enterprise market and wide area network are formed in this industry background and expectations.

The first time that the word SD-WAN appeared in the public eye was an article published in networkcomputing in September 2014, but in fact the concept of SD-WAN originated from the earlier Hybrid WAN, which is to solve the instability of Internet interconnection in the enterprise market. The MPLS VPN is expensive and game-like problems. At the same time, on the Open Network User Forum of ONUG in 2014, many enterprise users unanimously proposed such application requirements.

Since SD-WAN is an application driven by technology, there is no unified definition in the industry. Various industry analysis and consulting organizations such as IDC, Gartner, etc. have different definitions. In comparison, the definition proposed by SDxCentral can succinctly reflect the core idea of SD-WAN, that is, "SD-WAN is a service formed by applying SDN technology to a wide area network. This service is used to connect a wide geographical area. A wide range of corporate networks, including corporate branches and data centers."

Although in many consulting reports or manufacturer solutions, SD-WAN is often limited to the networking scenarios of enterprise branch interconnection. However, based on the definition of SD-WAN, in fact, the application scenarios of SD-WAN can be summarized into three categories: enterprise interconnection, data center interconnection and cloud interconnection scenarios. The application scenario of SD-WAN is shown on the right.

SD-WAN applications