This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.

Cost reduction and enhanced network performance are just two of the many benefits promised by SD-WAN technology. IDC believes the SD-WAN market will be a $6 billion industry by 2020, so it’s no surprise that solutions are popping up everywhere you turn.

At a high level, SD-WANs promise a more cost-effective and simpler way to operate secure, virtualized WAN connections between enterprise branches, data centers and the internet. Traditional MPLS links from the branch to the data center are reliable and secure, but typically offer lower performance for users accessing cloud-based services, and are considerably more expensive than widely available broadband access links.  The Internet provides global access to cloud applications, but is limited by poor reliability, unpredictable performance and weak security.

The benefit of SD-WAN is that it provides a software controlled and programmable environment that allows you to augment or replace your existing WAN, lower costs by leveraging cheaper broadband access links and dynamically scale bandwidth capacity to the cloud when needed.

But how do you know if SD-WAN is right for your business? Consider the following questions before you make the leap: 

* Do you actually need an SD-WAN? This is the rather obvious question, but with most new technologies, the hype can distract from the actual need. SD-WAN is no different. To get started, ask yourself the following:

• Am I reliant on MPLS or Carrier Ethernet services?
• Am I seeing more internet connectivity requests? For example, are my sales guys using salesforce.com or social media for sales and enhanced customer support? Or, do customers in my retail outlet want to browse the internet while they wait for service?
• Am I migrating in-house IT systems to the cloud?

Enterprise network traffic has exploded with organizations incrementally adding bandwidth to reduce service latency and avoid network failures. And, because many of today’s applications are moving out of the enterprise and into third-party cloud and SaaS environments, traffic flows within the network have drastically changed and become inefficient. Adding direct internet connections and broadband circuits can provide the needed bandwidth, but it also requires purchasing, deploying and managing daisy-chains of on-premises devices for different circuits and network functions, including routing, WAN optimization and firewalls at multiple locations.

If you answered yes to any of the questions above, SD-WAN can provide new choices. With SD-WAN, you can prioritize application and traffic flows, reduce the number of on-premise devices, as well as more dynamically manage the services deployed at a given branch location.  Together, this translates into lower capital expenditure and operating expenses overall. These solutions can also provide visibility into application performance so you can optimize your end-user experience.

* What are the pitfalls? One of the major selling points with SD-WAN is you can avoid service provider lock-in by buying and deploying the components internally or working with multiple service providers. However, whether you buy or lease your WAN, it requires a deep understanding of the network. You need to understand what type of traffic traverses your network; you need to know what applications are preforming well and what needs to be changed or optimized.

There are several vendors and offerings on the market so you should consider the time it will take to research and select products, and if you have the engineering expertise required to build and monitor the SD-WAN. Also, you’ll need to determine what traffic you want to keep on your existing network and which you want to send over the internet. How should you configure traffic management policies? What security measures need to be implemented? Answering those questions requires a deep understanding of application performance, network security, and network engineering.

Another pitfall is to think of SD-WAN as a complete solution, rather than another tool in the toolbox. So, while SD-WAN may enable choice in access, it doesn’t give you full connectivity to the cloud. In other words, to connect from remote sites to cloud services, it is the combination of orchestration of cloud, WAN and SD-WAN access that completes the solution.  Orchestration allows you to coordinate and automate across different pieces of the network.  SD-WAN is an important part of how the enterprise access the WAN. The combination SD-WAN and orchestration provides that comprehensive solution for integrating the enterprise to the WAN and into the cloud. 

* Do I build it or do I buy it?  If you decide SD-WAN is the way to go, you’ll have to decide if you want to build it yourself or consume SD-WAN as a managed service. Each option has its pros and cons.  The key question is, just how critical the network is to your business? If you’re in financial services, you’ll answer that differently than your IT peers in the retail industry. When the network is absolutely critical to your business you probably want more customization. If your needs are more flexible, you can work with different “off the shelf” options.

When you take the “buy” route and get your SD-WAN as a managed service, someone else is owning and managing the solution, saving your operations staff valuable training and support time.A buy option also may allow you to take advantage of other resources that your service provider offers, such as  NFV-based firewalls or cloud connectivity, giving you a more robust catalog of managed services that might be hard to develop internally.

Building it out yourself, on the other hand, offers the ultimate in customization. You can develop the services that work for your business and can be infinitely flexible.