For detailed SD-WAN (SDWAN) Vendor and Open Source comparisons, checkout the Virtual Edge Expanding: The 2017 SD-WAN and vCPE Report also available as PDF Download
Introducing a Software-Defined WAN
The software-defined wide-area network (SD-WAN or SDWAN) is a specific application of software-defined networking (SDN) technology applied to WAN connections, which are used to connect enterprise networks – including branch offices and data centers – over large geographic distances.
A WAN might be used, for example, to connect branch offices to a central corporate network, or to connect data centers separated by distance. In the past, these WAN connections often used technology that required special proprietary hardware. The SD-WAN movement seeks to move more of the network control is moved into the “cloud,” using a software approach.
SD-WAN (SDWAN) Business Drivers
Enterprise customers are demanding more flexible, open, and cloud-based WAN technologies, rather than installing proprietary or specialized WAN technology that often involves expensive, fixed circuits, or proprietary hardware.
Many of the new software-defined WAN offerings, for example, can be used to improve and secure Internet connectivity, making it more competitive with more expensive legacy WAN technologies such as T-1 or MPLS. In some cases, software-defined WAN technology uses Internet broadband connections to replace more expensive solutions. Virtualization technology can apply security and virtual private networking (VPN) technology to broadband Internet connections, making them more secure.
Software-Defined WAN also has the advantage of removing potentially expensive routing hardware by provisioning connectivity and services via the cloud. Emerging SD-WAN technology can also be more flexible. For example, because SD-WAN connectivity can be controlled through cloud software, a customer might be able to scale up or “burst” connectivity during times of peak demand.
Customer Focus: Cost, Reliability, Security
The main goal of SD-WAN (SDWAN) technology is to deliver a business-class, secure, and simple cloud-enabled WAN connection with as much open and software-based technology as possible. This can be used to deliver basic WAN connectivity, or it can be used for premium business services such as VPN, WAN optimization, and applications delivery control (ADC).
Many new startups are going after the potential in the software-defined WAN market, which is likely billions of dollars. Many of these startups have slightly different approaches to the market. For example, Silver Peak has focused on accelerating Software-as-a-Service (SaaS) applications in the cloud, VeloCloud goes after branch-office connectivity, and Aryaka has built a global network so that companies can use WAN as a Network-as-a-Service (NaaS).
Incumbent WAN technology vendors such as Cisco and Riverbed, which make specialized appliances for WAN connectivity, are now focusing more on cloud-based WAN offerings in response to this new trend.
Expect the trend to accelerate over the next few years. What started as a solution for branch-office and data-center WAN connectivity requiring less proprietary equipment appears to be expanding into a wide range of SD-WAN (SDWAN) offerings and technologies including VPN, security, WAN optimization, NaaS, and application policy control.