Understanding SD-WAN: What Is It and Why Does It Matter?

By: Brad Casemore - Leave a comment



Sponsored by IBM.

Without question, the wide area network (WAN) is critical to the success of enterprise hybrid-cloud strategies and initiatives. Although WAN optimization and traditional WAN services have addressed a broad range of client/server requirements, other capabilities are required for 3rd Platform applications and cloud computing.

Hence, the rise of the software-defined WAN (SD-WAN), which leverages the principles of software-defined networking (SDN) and adapts them to the needs of enterprises seeking to optimize application delivery in the cloud era.

SD-WAN is a relatively recent phenomenon, preceded by the existence of hybrid WANs. A hybrid WAN includes at least two WAN connections from each branch office leveraging two or more different access technologies (MPLS, broadband Internet, 3G/4G, or optical). SD-WAN often encompasses hybrid WANs, but it includes a centralized, application-based policy controller, analytics for application and network visibility, a software overlay that abstracts underlying networks, and an SD-WAN forwarder (akin to a router) that provides intelligent path selection across WAN links (MPLS, broadband Internet, LTE, etc.) based on the application policies defined on the controller.

SD-WAN business benefits can include cost-effective delivery of business applications, meeting the evolving requirements of the modern branch/remote site, accommodating software-as-a-service (SaaS) and cloud-based services, and improving branch-IT efficiency through automation.

Indeed, SD-WAN gained increasing mindshare in 2015, and IDC predicts SD-WAN revenue will ramp strongly in 2016 across a range of vertical markets. IDC believes that SD-WAN’s value proposition – predicated on the growth of cloud computing and the business imperative of reducing MPLS costs – will be compelling for a growing number of enterprises customers seeking to provide cost-effective networking to branch offices and remote sites.

Technology vendors and service providers will seek to address the enterprise demand, and competition among vendors will be fierce. In fact, IDC believes that at least two SD-WAN startups will be acquired by large, more-established players before the end of the calendar year.

Meanwhile, IDC anticipates that at least two major communications service providers (CSPs) will introduce SD-WAN services this year. Some CSPs will see SD-WAN as a complement to their existing MPLS businesses, while others will perceive it as a threat, but increasingly they will have to respond in some fashion to enterprise demand.

What remains to be seen is how enterprises will want to consume SD-WAN. The preferences could differ across geographic and vertical markets. Some enterprise customers will want to obtain SD-WAN as a service from their favored CSPs or MSPs, whereas others will opt to buy SD-WAN offerings from technology vendors and deploy them onsite. Alternatively, some SD-WAN solutions will be offered as a cloud-based service, with cloud-based management.

Many enterprises are likely to consult with trusted partners before choosing an approach to SD-WAN that is best suited to their needs. Before making their selection, these enterprises will want to fully understand the pros and cons, and the operational and technological implications, of each option.

Regardless, as enterprises plan and implement comprehensive cloud strategies, it is clear that SD-WAN has emerged as a prominent consideration.

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About The Author

Brad Casemore

Research Director for Datacenter Networks, IDC

Brad Casemore is IDC’s Research Director, Datacenter Networks. He covers networking products and related technologies and platforms typically deployed in the data center. Brad leads IDC’s Datacenter Networks program, and works closely with IDC's Enterprise Networking, Server, Storage, Cloud and Security programs to assess the impact of emerging IT and converged-infrastructure solutions.