Software-Defined Wide Area Networking: A Practical Guide To Implementing Hybrid WAN


For businesses that are reluctant to adopt software-defined wide-area networking (SD-WAN), it’s important to remember that it doesn’t have to be an all-or-nothing migration.  Easing into the many proven benefits of SD-WAN – such as reduced total cost of ownership (TCO), flexible bandwidth options, and unprecedented simplicity of networks and applications – can be a gradual process, without sacrificing existing investments in traditional networking infrastructure.

Businesses that have incorporated SD-WAN into their network strategies are finding that it is a viable and cost-effective solution to meet the escalating connectivity demands of increased branch dispersion and growing dependence on cloud-based applications.

Research validates that businesses nationwide are taking note. In fact, IHS Markit’s March 2017 survey of 163 midsize and large enterprises revealed that North American enterprises expect their WAN expenditures to rise by more than 20 percent annually.  Four out of five respondents noted that they plan to adopt SD-WAN over the next four years.

Still, these adoption numbers appear low and slow for proponents of a new technology with such proven returns.

“Early adopters of software-defined networking are finding great return on investment (ROI) and TCO.  But, despite the early success, it appears the majority of organizations are slow to hop on the SDN bandwagon,” according to Computer Economics’ Technology Trends 2017 study. 

Why the reluctance?  Many IT decision makers hesitate because they are loath to abandon their investments in traditional, hardware-based networking architecture.  There is also a valid concern about staffing and cultural changes in the IT workplace that a shift from hardware to software-driven architectures would introduce.

TechTarget’s new report, Network’s Next Sea Change, the SDN WAN, predicts, “The software-defined WAN appears poised to catalyze a sea change in the enterprise space, transforming WANs from inflexible and expensive to agile and cost-effective, and dramatically altering network engineering career prospects and job descriptions in the process.”

How can enterprise IT leaders overcome their well-founded concerns and take advantage of the opportunities afforded by SD-WAN?  For starters, follow this simple guide to implementing your SD-WAN transition with a hybrid approach that minimizes disruption and initial hardware turnover:

  • Start incrementally.SD-WAN is readily available for pilot testing, so you can try it on a small-scale, side-by-side trial with your existing infrastructure.
  • Implement a trial as an option for an affordable, logical solution to augment your legacy network, or to provide redundancy.
  • Test-drive it as a managed service, avoiding any upfront capital investments.
  • Introduce a limited SD-WAN implementation that is dedicated specifically to a new application or service that you’ve not been able to bring on because of current network constraints.
  • Pilot it as a connection to one or two branch offices, and continue connecting others over your existing network.
  • Use it to replace aging routers as they depreciate or reach the end of a contract, to avoid the expense of a hardware refresh while incrementally introducing SD-WAN to your enterprise.
  • Start with a small implementation to support specific applications or traffic, to gain a comparison to your current MPLS network and have the opportunity to determine whether SD-WAN is right for your enterprise.

For whatever reason you may be considering SD-WAN and its fit for your business’ strategy and culture, remember that there is no need for an initial wholesale abandonment of your existing networking architecture.  Small-scale implementations offer a viable and cost-effective strategy for any business to begin realizing the many benefits available through software-defined wide area networking.


Small scale SD-WAN initiatives offer a viable, cost-effective strategy for business to begin realizing the many benefits of software-defined wide area networking.

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