Learn about deployment options and other considerations for choosing software-defined WAN.
When it comes to software defined networking, many enterprises start at the WAN. Software-defined WAN is easy to conceptualize, relatively simple to deploy – and more importantly – the technology makes it easy to calculate and prove an ROI. That said, the SD-WAN market is evolving rapidly with many vendors jumping into the space. Choosing the right product for your environment can be challenging.
SD-WANs allow you to leverage multiple forms of WAN connectivity, most commonly MPLS and broadband Internet. Next, an SD-WAN provides dynamic path selection based on application and data flow policies you create. While the methods used to gain these features may vary from one product to the next, the outcome is relatively the same. Instead, your decision-making process should focus on two primary areas: deployment options and infrastructure compatibility.
Right now, there are three primary deployment options with a fourth that's growing in significance. Early SD-WAN platforms were deployed on-premises and required in-house networking staff to design, deploy, and manage SD-WAN hardware and software. Some of these products required proprietary hardware to deploy, although most could be deployed on virtual machines. Regardless, customers were fully responsible for building and maintaining their SD-WAN from end-to-end. This is still an option today if your organization requires full control over the WAN.
A SD-WAN deployment model that is growing in popularity is a product that is fully cloud managed. This typically involves a SD-WAN virtual machine at both the corporate and remote site edge, but the configuration and deployment intelligence is controlled and managed in the cloud. This reduces complexity and offers greater scalability.
Another SD-WAN choice would be to use what’s known as a managed SD-WAN. With this deployment model, you typically partner with a WAN carrier that would be responsible for the management your entire SD-WAN. You’d only need to provide configurations regarding how you want traffic handled as it traverses locations. While this is a sound option for some, others fear that it locks their WAN connectivity options to a single WAN connectivity provider.
A final architectural consideration is the growing need to provide intelligent path selection as it relates to mobile devices such as smartphones. As businesses become borderless and workforces continue to work outside the office, it’s becoming increasingly important that these users are provided with similar latency and redundancy service levels regardless of where they connect physically. Some vendors offer the ability to connect to a network of dynamically routed content distribution networks (CDNs) in an SD-WAN architecture. Future options I expect to see include smartphones using bonded carrier 3G/4G/LTE and WiFi connections simultaneously and with intelligent path selection.
Other than deployment options, an enterprise must also take its current infrastructure architecture into account before choosing an SD-WAN solution. Some feel that a single-vendor solution provides a more seamless SD-WAN deployment and fewer headaches when troubleshooting path selections that have gone awry. For example, if you're using Cisco gear across your network, you may want to consider sticking with Cisco for SD-WAN.
Another important consideration is the potential use of SD-WAN in public IaaS and PaaS clouds where much of your data and applications reside. Some vendors offer their SD-WAN products direct through cloud provides marketplaces such as the AWS Marketplace. This method can significantly streamline deployment times and provide a solution that is at least partly supported by the cloud provider. You should perform due diligence to verify that the product you end up choosing is optimal on private/public infrastructures and provides the necessary bridge between the two.
Finally, when weighing your SD-WAN options in today’s market, consider how an overall software-defined networking (SDN) architecture may eventually shape the future of your entire enterprise. Ideally, you'll have a single, unified solution to cover path selection intelligence not only at the WAN edge, but also in the data center, out to the cloud, and across the corporate campus LAN.
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