SD-WAN Use Cases

Software-defined WAN (SD-WAN) has gone from emerging technology to a staple of enterprise networks at an impressive rate. Just how ubiquitous is SD-WAN becoming? A Cisco-sponsored study by IDC reported that 94.9% of organizations have deployed or plan to deploy SD-WAN technology by October 2020. Another study from Cato Networks was more conservative but it found that of the more than 1300 IT managers surveyed, 48% of enterprises expect SD-WAN adoption to be a primary IT use case in 2020.

What’s most interesting about SD-WAN’s rapid growth is the variety of use cases driving it. There isn’t a single, one-size-fits-all application where SD-WAN has found a niche. Rather, enterprises are leveraging the upsides of different SD-WAN solutions from different vendors to solve a variety of different business challenges. This, in turn, explains the surge in popularity.

So, what are those different use cases? Let’s take a look.

Support cloud for workloads

MPLS (multiprotocol label switching) has proven to be too expensive and inflexible for cloud workloads. With multi-cloud environments, where enterprises use cloud services from multiple vendors, becoming the norm, the demand for a more flexible alternative to MPLS has increased. As a result, solutions that enable affordable cloud connectivity are in high demand. SD-WAN allows enterprises to route cloud-bound traffic over public Internet links, while continuing to route internal traffic over MPLS connections. While this use case is straightforward, it can have a significant impact on bandwidth costs and continues to be one of the key drivers of SD-WAN adoption.

Adding resilience to the WAN

By creating virtual overlay and aggregating multiple transport methods (MPLS, broadband, LTE, etc.) SD-WAN makes it easy to eliminate single points of failure within the WAN. If a given link goes down, SD-WAN can automatically route traffic over a backup link often without interrupting an application session. Additionally, from a performance perspective, SD-WAN can be used to load-balance traffic across last-mile connections, ensuring a given link doesn’t become a network bottleneck.

Streamline mergers and acquisitions

Mergers and acquisitions (M&As) can create major WAN challenges. In many cases, M&As require IT to integrate multiple sites with disparate network topologies, infrastructures, and applications. This can lead to challenges such as duplicate IP address ranges & overlapping subnets, manual configuration of network tunnels, and long deployment times while enterprises wait for MPLS links to be provisioned (often measured in weeks or months).

SD-WAN helps solve these problems in a few ways. First, SD-WAN provides enterprises with a flexible management interface that enables IP conflicts and subnet issues to be resolved simply and reduces the need for manual configuration of network tunnels. Further, SD-WAN drastically reduces deployment times because it enables WAN traffic to be routed over any network infrastructure. In many cases, deployment times can be reduced from months to days. As a result, this allows enterprises to become more productive in less time.

Cost-effective MPLS replacement

Thus far, the functionality we have described can be delivered by most basic SD-WAN solutions. However, that is not the case for MPLS replacement. One of the fundamental benefits of MPLS is predictable and reliable connectivity that is backed by an SLA. SD-WAN edge appliances that only serve as a network overlay cannot match MPLS reliability, and as a result are often used to complement MPLS as opposed to replacing it. Cloud-based SD-WAN, on the other hand, can replace MPLS outright.

The reason cloud-based SD-WAN providers can serve as a direct replacement for MPLS is that they provide predictable and reliable transport over a global private network. As opposed to depending upon MPLS for reliability, cloud-based SD-WAN providers offer a global private backbone that is supported by an SLA.

Secure branch Internet access

Another advanced SD-WAN use case is secure branch Internet access. MPLS and SD-WAN edge appliances require additional solutions such as NGFW (next-generation firewall), IPS (intrusion prevention system), and UTM (unified threat management) to enable enterprise-grade security. With MPLS and SD-WAN appliances, enterprises generally use one or more of these approaches to add security to the network:

Backhauling branch Internet traffic to a specific network location (e.g. a firewall at a corporate datacenter), which can have a significant impact on latency-sensitive applications
Deploying security appliances at each branch location, leading to management complexity and appliance sprawl
Using proprietary cloud security solutions, which can limit visibility and create security silosCloud-based SD-WAN solutions solve this problem by providing enterprise-grade security features

Cloud-based SD-WAN solutions solve this problem by providing enterprise-grade security features within the appliances that interconnect the network. This converged approach to networking and security makes securing Internet access from branch locations significantly easier to manage while also avoiding inefficient backhauling through a single network security appliance. The result is full network visibility and a more scalable and secure network.

Connecting and securing the mobile workforce

Remote work and BYOD (bring your own device) policies have led to a surge in the number of mobile users connecting to enterprise networks. While there is plenty of upside to the increase in mobile work, it has created a challenge for network managers. Connecting mobile users to MPLS or SD-WAN appliances directly usually isn’t an option. This creates a gap in enterprise security posture that enterprises must either address or learn to live with.

The nature of cloud-based SD-WAN enables it to solve this problem as well. Mobile users can securely connect to the nearest PoP from a cloud-based SD-WAN provider using either a mobile client or web browser. From there, they receive the same protection and performance as on-premises users.

Finding the right SD-WAN solution for your business

As we’ve seen, there isn’t one reason enterprises are turning to SD-WAN, there are many. Similarly, there isn’t just one approach to SD-WAN, there are several. Making the right choice for your business requires quantifying your network challenges and selecting a solution that meets your needs. If you’re stuck in a long-term MPLS contract, a simple SD-WAN edge appliance to reduce cloud costs may be a wise investment. Alternatively, if you need a holistic networking and security solution, cloud-based SD-WAN is worth a look. The key is matching the right technology to the challenges facing your business.