Understanding SD-WAN: What, Why, and the Benefits

Software-defined wide area networks (SD-WAN) continue to change the networking marketplace and have risen to prominence in a range of industries – including retail and manufacturing. And its popularity is increasing.

Gartner estimates that 65% of enterprises will have implemented an SD-WAN by 2025, such is the level of interest in the technology. To cut through the fog and elevate your understanding of SD-WAN, the benefits, and what to expect from an SD-WAN managed service, we've put together this handy introduction.

What is SD-WAN?

SD-WAN technology differs from the traditional hardware-centric networking approach. It can transform enterprise networks from slow and fractured to agile and  optimized  and supports chaining for additional services such as wide area network (WAN) optimization and firewalls. 

An SD-WAN achieves this by utilizing overlay tunnels on top of available transport links to transfer data. These transport links include multiprotocol label switching (MPLS), asymmetric digital subscriber lines (ADSL), and others. While critical data is predominantly sent along MPLS links, less important everyday data can be sent along broadband connections. This reduces both the cost and the need to have MPLS carry both sets of information.

One of  SD-WAN’s  chief characteristics is the provision of dynamic, policy-based application path selection across multiple WAN connections. This makes it possible to reduce MPLS – or other expensive fixed internal WAN – circuit costs by directing some or all of the traffic over encrypted channels. Put simply, an SD-WAN offers a lightweight replacement for the traditional router.

Unsurprisingly, SD-WAN has experienced high growth within the WAN market in recent years. But dedicated routers and WAN optimization controllers are still being widely deployed in enterprise environments. Many SD-WAN deployments today aren't replacing traditional routers at all; they're supplementing them. This helps to increase risk aversion and reduce the lack of support for legacy infrastructure. 

Understanding SD-WAN and why you need it comes down to a range of factors.

Many enterprises struggle with the price, performance, and flexibility of their traditional WANs. And this problem has only been compounded by the growth of public cloud applications.

Moreover, many enterprises have  complex  infrastructure at their branch or offices. These typically consist of routers, WAN path controllers, WAN optimizers, firewalls, and other components that are expensive to buy, complex to manage, and difficult to maintain. 

SD-WAN technology represents a solution to these problems.

An SD-WAN makes it possible to bond multiple WAN connections together – internet, MPLS, or any other transport pipe – to create a single bundled link that’s stronger than any one connection. This reduces dependency on expensive links, lowers costs, and increases overall network performance.

Additionally, by placing edge devices in enterprise environments, it’s possible to control and shape bandwidth at an unlimited number of sites using a centrally managed interface. This reduces maintenance costs and eliminates management complexity.  

Benefits

The benefits of an SD-WAN are substantial. Compared to traditional WAN products, an SD-WAN:

• Reduces capital and operational costs at the WAN edge
• Improves provisioning times
• Enhances branch uptime

Enterprises can incorporate SD-WAN technology to leverage different network technologies as a matter of policy. Instead of having to configure network hardware directly, an SD-WAN centralizes WAN management, enabling greater control, flexibility, and agility when allocating enterprise network resources.

SD-WAN Managed Services

Implementing an optimized, cost-effective SD-WAN environment requires you to have a firm grip on your network infrastructure. But for many enterprises, the biggest challenge is managing the shift from a hardware-centric to a software-defined network architecture. It can be time-consuming and expensive, and many enterprises don't have the skills or resources to coordinate the switch internally.

Increasingly, telecom expense management (TEM) providers offer managed SD-WAN services to reduce the stress of implementing, managing, and optimizing enterprise solutions.

SD-WAN managed services provide a wide range of benefits, including:

• SD-WAN benchmarking, sourcing, procurement, and solution implementation
• Auditing and optimizing your existing network environment
• Long-term management and support
  

Limitations

The prime limitation of an SD-WAN is  that,  as a relatively new technology, it doesn't always address the full complement of functions enterprise branches need. Many commercial products in the market lack robust security, voice, and WAN optimization functionality, while many of today's SD-WAN products don't support legacy infrastructure.

Fortunately for enterprises, continued growth in the SD-WAN market has addressed many of these limitations.

Marketplace

The networking marketplace includes multiple functions, deployment methods, and consumption models, and has experienced substantial innovation in the past few years. 

For IT and telecoms professionals interested in SD-WAN  technology, the challenge is understanding the real processes involved in an SD-WAN transformation. This includes how to incorporate expenditure and cost savings, and whether switching makes sense financially. 

SD-WAN has already had a substantial impact on enterprise networking, as vendors seek to disrupt the long-standing WAN reliance. 

Need More Help Understanding SD-WAN?

Understanding SD-WAN is the first in a six-part series that will explore everything an enterprise needs to know about SD-WAN, and how leveraging  an SD-WAN  solution with existing infrastructure can provide substantial business benefits.

In part two, we focus on the 5 key benefits of SD-WAN for enterprise environments. We also explore why interest in SD-WAN technology continues to grow as enterprises seek more responsive, flexible, and available networks.