The first two parts of this series examined why your organization's digital transformation strategy is likely creating a performance gap between what your business needs and what you can actually deliver.

Start with Making Digital Transformation Work for You – Part 1

Start with Making Digital Transformation Work for You – Part 2

So now let's explore how to close that gap by building a more capable and scalable network. A network that bridges this performance gap and positions IT as a services provider is critical to helping businesses grow and succeed. The first step is realizing that legacy remote networks built on a collection of individual switches and routers are obsolete, and how implementing SD-WAN can enable you to achieve new levels of agility and efficiency in serving the needs of your business.

The hybrid IT environment has become the norm as enterprises migrate infrastructure and applications that have been traditionally managed on-premises in branches and data centers out of these locations and into the cloud, leveraging Infrastructure-as-a-Service (IaaS) and Software-as-a-Service (SaaS) offerings. This move to Internet/cloud-based services has, in turn, had a direct impact on how network architects design their remote networks. Today, Internet broadband-based connectivity is increasingly being used to directly connect remote locations to cloud-based services, augmenting or even in some cases replacing traditional MPLS-based networks.

But while Internet broadband circuits offer typically higher capacity than traditional MPLS circuits, and while remote Internet connectivity at branch locations can reduce latency to Internet-based services by eliminating the need to backhaul Internet-bound traffic to a core data center, it also brings with it a new set of costs and challenges.

Costs and Challenges

Managing hybrid (MPLS + Internet) WAN topologies with legacy approaches to branch networking is operationally intractable. Even small changes in configuration are hard to get right and all too often compromise the availability, performance and/or security of a distributed network.

The lack of complete visibility into network behavior and application performance creates other management headaches, with encrypted apps (SSL, TLS, HTTPS) and SaaS vendor opacity compromising end-to-end visibility.

These issues are NOT the result of a fleeting trend or short-lived fad. They're not going to suddenly disappear. Enterprises are going to continue adopting more Internet-based applications and services, deploy more video and other bandwidth-intensive applications, and deploy hybrid WAN technologies at remote locations. These management challenges are driving software-defined wide-area-networking (SD-WAN) as the preferred option for managing today's hybrid networks.

What is SD-WAN?

SD-WAN enables network architects and operators to take a holistic approach that hides the underlying complexity and makes orchestrating enterprise and cloud connectivity "point-and-click" easy. According to Garter, "SD-WAN is a new and transformational way to architect, deploy and operate corporate WANs, as it provides a dramatically simplified way of deploying and managing remote branch office connectivity in a cost-effective manner."

Instead of trying to manage thousands of manually configured routers, IT can centralize management via virtual network design, zero-touch provisioning, and business-aligned policy-based orchestration.

SD-WANs Are Just the Beginning

While SD-WAN is a critical part of a modern approach to managing hybrid WANs, the story shouldn't begin and end at the WAN's edge. Businesses should look to extend the benefits of software-defined networking across hybrid WANs, cloud networks, as well as branch LAN/WLANs. The benefits of zero-touch provisioning should streamline connectivity across physical locations and cloud infrastructure networks (e.g. AWS & Microsoft Azure) alike. And automation and orchestration of policies to enforce application performance SLAs and/or security access constraints should apply ubiquitously across WAN transports, cloud environments and even where users connect into remote LANs and Wi-Fi networks.

Modern networks must provide visibility and optimization end-to-end across on-premises and cloud environments to ensure NetOps can ensure consistently high performance levels of business applications and productivity for end-users.

Just as application and information availability is critical to users, so too is protecting those assets from cyber attackers. It's impossible to avoid the fact that an organization's security posture weakens as its hybrid networks grows larger and more complex. Direct Internet access at multiple remote sites typically bypasses data center-grade security services, and encrypted apps (SSL, TLS, HTTPS) and SaaS vendor opacity compromise end-to-end visibility. Limited MPLS capacity and no SLAs for Internet broadband result in unpredictable performance slowdowns that users will notice.

Establishing end-to-end visibility across the entire network enables you to strike the necessary balance between ensuring network performance and security. Therefore, when evaluating SD-WAN technologies, keep three key questions in mind:

1. Does it provide unified connectivity and management across WAN, remote LAN and cloud networks?

2. Does it enable the creation and implementation of global or local policies instead of the traditional approach of managing networks through the configuration of individual appliances?

3. Does it bring the agile and simplified cloud-centric workflow to the network? This includes providing an intuitive GUI that makes managing managing networks, zero-touch provisioning, and central management of global network policies.

According to industry experts, the SD-WAN market is really starting to heat up as many companies are planning to adopt these technologies in the near future. IDC earlier this year predicted the emerging SD-WAN industry will grow at a more than 90 percent CAGR for the next five years to become a $6 billion industry by 2020.

Put simply, after two decades of industry dominance by a single hardware provider that stalled innovation and stunted the network's evolution, even as the rest of the IT architecture raced to the cloud, we're entering an exciting software-defined age.

Joshua Dobies is VP of Product Marketing, Riverbed Technology.