Summary Bullets:
• Customers should approach SD-WAN with an open mind when it comes to costs and understand that savings may come from knock-on benefits.

• Customers should conduct their own trials into whether the internet is appropriate for a given application.
Cost Savings vs. Quality
Much of the initial hype about SD-WAN focused on cost saving. However, those looking to buy an SD-WAN solution should keep an open mind to cost and be aware that if savings are realized they may not come from the cost of their WAN solution. Indeed, initial experience suggests that SD-WAN solutions sometimes increase the cost of an enterprise’s overall spend on WAN. The complexity of managing SD-WAN means that it is not an inherently cheap technology. WAN savings may come over time as more and more MPLS is phased out of WAN architectures, but initial experience suggests that abandoning MPLS from day one is a risky approach and often results in unsatisfactory network performance.
However, enterprises who have invested the time and money into achieving a best-fit solution for their business (often achieved through conversations with AS-WAN vendors and managed service providers) attain enhanced performance of their network and more business outcome-oriented SLAs. Furthermore, enterprises report that a more efficient network allows them to achieve savings and performance boosts across their wider business. SD-WAN is not a panacea, but if used as a feature within a wider digital transformation process then the initial outcomes have been broadly positive.
Quality and Appropriateness of the Internet
Customers should be aware that ‘the Internet’ is a very wide-ranging term and that best value from SD-WAN will be achieved when the internet component is managed as much as possible. Customers should question providers about the reach of their own backbone, the aggregation partnerships they have, and what performances guarantees/SLAs the provider can offer over the Internet.
Clients should also seek to have a real and tested understanding of the kind of connectivity their applications need and conduct experimental real-world testing to see if the internet will be enough. Many will find that it the internet is enough for most applications, especially modern ones designed to run in cloud environments, but this will not always be the case.
Security
In almost every survey of enterprise ICT priorities, security comes out one the top three challenges/concerns. This is no less true when it comes to SD-WAN. Increased exposure to the Internet is not new, but it needs to be properly managed. Customers should work with firewall and SD-WAN vendors and managed service providers to understand whether the inbuilt firewall capabilities provide the appropriate functionality. Customers should be aware that the ‘native’ security features of SD-WAN solutions have developed rapidly and there is an emerging sub-sector of SD-WAN solutions from vendors such as Fortinet that start from the firewall. However, a separate firewall may still offer the most appropriate solution.