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SD-WAN explained: Getting your questions answered

Our SearchSDN networking experts aim for SD-WAN explained in this Q&A compilation, with topics ranging from vertical markets it can benefit to the merits of WAN optimization vs. SD-WAN.

Software-defined WAN has transitioned from a "will-be" to a "happening-now" technology. As its popularity grows...

-- along with the number of deployments -- numerous questions, considerations and doubts emerge. We've compiled some of our top questions and answers about SD-WAN, explained by our SearchSDN experts. These questions address how SD-WAN works, architecture consideration, potential SD-WAN benefits and more.

Is it hybrid WAN vs. SD-WAN, or does SD-WAN help implement hybrid WAN?

In the SD-WAN hullabaloo, it's easy to get confused with various terms, like hybrid WAN and SD-WAN. Lee Doyle, principal analyst at Doyle Research and an expert on SD-WAN, explained that although these two technologies are often used interchangeably, they are indeed separate. According to Doyle, however, the two complement each other.

Knowing how SD-WAN works is key to understanding the difference between hybrid and software-defined WANs. SD-WAN provides an abstracting overlay to various WAN links and offers the ability to monitor and prioritize WAN traffic by determining the best links for each case. This capability thus enables and enhances hybrid WAN, which uses a combination of links -- like MPLS, broadband or fiber -- for network traffic.

Read the rest of Doyle's explanation about hybrid WAN and SD-WAN.

Are SD-WAN and WAN optimization techniques merging?

While SD-WAN is relatively new to the market, WAN optimization has been around for decades. Andrew Froehlich, a networking consultant and president of West Gate Networks in Loveland, Colo., answers the question of whether SD-WAN encompasses WAN optimization. SD-WAN brings visibility, control and intelligent monitoring to the network; WAN optimization aims to maximize throughput. Used together, they become complementary.

Most organizations, Froehlich said, would prefer one offering that includes the benefits of both SD-WAN and WAN optimization. In fact, vendors like Riverbed Technology and Silver Peak -- once primarily WAN optimization vendors -- now offer their own SD-WAN products.

 Look over Froehlich's discussion about WAN optimization and SD-WAN.

Will edge routers be replaced as SD-WAN growth continues?

Edge routers have been essential to networks for years. As the software-defined WAN trend dominates, however, speculation about the prosperity of the edge router market ensues. Froehlich tackles this question to explain how SD-WAN could replace edge routers as appliances.

SD-WAN adheres to SDN principles of a centralized control plane and end-to-end visibility, which allows WAN routing, path selection and application optimization to occur in that same environment. Instead of dedicated router hardware at network edges, commodity hardware -- relatively inexpensive hardware that can be interchanged with other hardware -- can be used, he said.

Learn more about Froehlich's thoughts on edge routers and SD-WAN.

Which vertical industries can benefit from SD-WAN deployments?

Most vertical markets can profit from SD-WAN, Doyle said, but some specific markets could reap even more advantages from implementing the technology. Organizations that rely on IT applications for communication among locations, individuals and devices can especially benefit from SD-WAN technology, Doyle said. These industries include retail, banking and financial services, and manufacturing organizations.

Take a look at Doyle's answer on how SD-WAN works to improve these industries.

What SD-WAN architecture is best for your network?

For those who have decided to implement SD-WAN, the available choices can be overwhelming and the pressure to find the optimal SD-WAN architecture unending. But Zeus Kerravala, founder and principal analyst at ZK Research in Westminster, Mass., said it's more important to pay attention to your organization's network traffic.

Each organization's SD-WAN architecture will vary, just as each organization's business plan varies. Instead, Kerravala said to study network traffic patterns quarterly and base an SD-WAN plan on those changes. Flexibility is integral to how SD-WAN works, and network architects can use this characteristic to their advantage while planning for SD-WAN.

See what else Kerravala said about choosing SD-WAN architecture for your organization.

Was SD-WAN explained, or do you have still have questions? Let us know in the comments below.

Next Steps

Use this primer to learn about SD-WAN

A list of SD-WAN vendors to get you started

Prepare for SD-WAN deployment with these steps

This was last published in June 2017

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