The expectation of anytime anywhere access to bandwidth-intensive enterprise applications, including the growth of cloud services, has put a tremendous strain on traditional WAN infrastructures. Not only that, as remote offices have become the norm and mobile devices, video, and real-time applications continue to increase, many believe legacy enterprise WAN has reached its breaking point.

Some see the introduction of Software Defined WAN (SD-WAN) as the answer to this increased strain on Wide Area Networks (WAN). Software-defined WAN is an extension of Software Defined Networking (SDN) because it uses software and virtual network overlays to take advantage of available WAN connections. It also centralizes control of and visibility into the entire WAN fabric and thus lowers the cost and complexity of WAN management. SD-WAN technology applies policy-based routing of traffic across multiple WAN connections. It essentially pushes data on the most optimal route across the network. Packets travel the network to and from different branch locations, taking the best route, to avoid latency issues and network slowdowns. SD-WAN offers many significant benefits:

    • Lower costs- enterprises can rely more on lower cost, public broadband and less on MPLS networks.
    • Flexible management and reduced complexity- SD-WAN routes and reroutes traffic based on the current state of the network, as configured by policies.
  • Greater redundancy options- Predetermined routes are created and data is automatically re-routed from primary to a secondary Internet connection.

Although SD-WAN offers more agile internet connections at a lower price point, it’s important to remember that not all SD-WAN solutions or service providers that offer it, are created equal. If your organization is considering moving away from a traditional WAN, it’s important to consider possible limitations of the technology and how it may impact your business.

Bandwidth lock-in

Calculating the potential return on investment of adopting an SD-WAN seems relatively straightforward at first. Because software-defined WAN uses public internet broadband and minimizes the need for private circuits, most companies report significant cost savings. Companies surveyed by IDC estimate a 20% cost savings with SD-WAN, compared to traditional WAN deployments. (Source: IDC July 2016).

However, consider the fact that your organization may be locked into a multi-year deal on private circuits. Downsizing could trigger severe penalties or fines for early termination. This and other service-level changes could further impact ROI, meaning it will take longer for your SD-WAN technology to pay for itself.

Challenging transitions

Just like any changes involving the enterprise network, transitions can create complications very quickly−especially when manual processes are involved.  Configuration mistakes will happen and, unfortunately, they’ll probably happen at severely inopportune times. Consider network automation tools and testing tools that help you maintain a logical IP network and the capabilities to manage the underlying infrastructure of the network. There are generally three types of software-defined WAN solutions and each has its advantages: Controller-based solutions auto-discover and configure network devices and can help in this transition period. Second, appliance-based overlay solutions create a virtual IP network between the vendor’s appliances across any network, combined with management tools. Last, advanced automation and change control solutions enable and manage SD-WAN and the underlying infrastructure through existing hardware.

If you’re evaluating software-defined WAN solutions, look for one that gives you centralized control of your networking environment. With a central point of control, you’ll have simplified access to management, policy setting, analytics and reporting of the SD-WAN fabric, which will be critical during the transition and once the SD-WAN is fully deployed.

Models for growth?

Another factor when evaluating SD-WAN technology is how the architecture will scale with your business over time. For instance, what options are there for adding remote offices or changing your network? Also, consider where your controller software will run.  In the cloud, as a virtual machine in the local network or in the datacenter? There are several SD-WAN products on the market and many are incompatible, so it’s important that part of your evaluation process includes looking at the potential long-term commitment to the vendor or service provider.

Many software-defined WANs give enterprises the ability to deploy a wide area network on-premise or cloud. Before selecting a vendor, ask the provider if they offer a pay-as-you-grow subscription model for cloud-based management.

Also, consider your organization’s long-term needs in terms of overall network efficiency. Some software-defined WAN solutions have analytics capabilities and allow administrators to analyze enterprise network traffic. Some also provide real-time and historical performance data to identify and address service issues. While network analytics may be too advanced during your initial SD-WAN deployment, don’t get stuck with a solution that has limited capabilities because of a shortsighted evaluation process.

If your organization is looking to improve the performance of applications and services in the cloud, as well as improve connectivity and reduced complexity of remote office networks, an SD-WAN architecture offers many benefits for forward-thinking enterprises.