The SD-WAN bandwagon has grown to include not only new providers and the incumbent networking vendors but also related solutions such as WAN optimization and WAN path control, and even wireless 4G.
So is SD-WAN over-hyped? Yes, it can be called "over the top," both literally and figuratively. In a literal sense, SD-WAN enables the deployment of an overlay logical network on top of Internet or MPLS transport. The advantage of separating the control plane from the data plane applies not only to SD-WAN solutions themselves but in effect to the diverse underlying physical transport.
Figuratively, SD-WAN is generating well-deserved interest from enterprises large and small. Continuing increases in bandwidth requirements are difficult to meet solely with private WANs such as MPLS and Metro E when branch locations are remote and expensive to reach with fiber. So, enterprises have been facing either a painful budget or a bandwidth issue -- SD-WAN can help solve the issue by using Internet broadband as transport to WAN networks. Its not really new, we've used VPNs before but early adopters have achieved cost savings by implementing hybrid networks. Often times you are able to upgrade a metro location's MPLS bandwidth for little or no increase and now you can upgrade remote branches by deploying SD WAN over broadband connections.
While hybrid networks with Internet mostly as backup have been deployed before, the policy-based simplicity of SD-WAN makes it practical to leverage diverse circuits from different providers across a large-scale deployment. The use of SD-WAN along with broadband circuits makes new location deployments much faster.
Changes in WAN architecture make sense because of the underlying shift to applications in the cloud. The Internet provides not only the cost and flexibility benefits, but it is the logical path to the cloud. Building private networks to connect to cloud hosted services affects the benefits of migrating applications to the cloud in the first place. The challenge has been to build a path to the cloud as robust, secure and manageable as a private network. SD-WAN technology that extends its managed overlay to cloud destinations can address this problem. But SD WAN fits a certain IT strategy. If your company intends to move all your applications to the cloud then SD WAN might be a good fit however if you still have mission critical data stored on local servers and want high quality VoIP then private networks such as MPLS and MOE are still a more secure, and are a simpler to manage WAN solution.
Don't buy the hype! If the strategy you are deploying fits the SD WAN model it can be a great solution, but if it does not you will be very dissatisfied. SD WAN is not a revolutionary money saving technology that fits every case, it is another tool that has some benefits in the right configuration. In fact MPLS can terminate in an SD WAN box and be supplemented by an Internet connection in the same box used as a fail over. SD WAN can be deployed in conjunction with private networks to create redundancy. Don't be fooled by all the marketing and constant sales calls, do your homework or talk to your consultant to see if SD WAN is a good fit for your network.
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