SD-WAN: More than a Hybrid WAN
June 7, 2017
Companies looking to expand their WAN networks are rich in choices: They can stick with a traditional WAN or go with a hybrid or SD-WAN architecture. Given the costs and provisioning delays associated with traditional WANs, a growing number of companies are turning to hybrid or SD-WAN.
It only makes sense: Because they facilitate the use of direct internet access (broadband) as an alternative method of branch connectivity. Hybrid and SD-WANs are much lower in cost than MPLS WANs. However, there are distinct differences between hybrid WAN and SD-WAN architectures that are worth noting, especially for companies looking for more than just an additional pipe for their data.
Hybrid WANs are just that: hybrid. They use two different types of connections (usually MPLS and the internet) to carry data traffic from branch offices to a central location such as corporate headquarters or a data center. It’s a great option for companies looking for additional resiliency, or to address their expanding bandwidth needs without shelling out a ton of cash for additional MPLS connections, or paying for data that doesn’t need to run over an MPLS connection.
Say, for instance, a company has branch offices scattered throughout the country that utilize a cloud service such as Office 365. Rather than send that traffic back to the corporate data center, which then will send the traffic to the cloud service, a hybrid WAN can send that internet traffic directly to its intended destination—in this case, the Microsoft Office 365 portal. That saves the company money by not routing unnecessary traffic over MPLS circuits.
Hybrid WANs, however, don’t have much operational intelligence. That’s where SD-WAN architecture comes in. As the the data plane is separated from the control plane, the data traffic can be manipulated and controlled to ensure the right traffic flows over the right connection and the best possible connection at the right time. For example, IT can direct sensitive or mission-critical data to run over the MPLS network and less-critical data to run over the internet, ensuring both speed of data delivery and quality of service. Plus, SD-WAN architecture has the intelligence to reroute traffic over alternative routes if there is an issue with their primary path. Hybrid WAN, in comparison, does not have that intelligence—it directs traffic over the same route every time and only uses another path if the primary path is no longer available.
SD-WAN architecture also embeds application intelligence, enabling deep packet inspection by the network beyond just a “source and destination” lookup to also include application and potential application context. That helps in ensuring mission-critical traffic is given top priority.
What’s more, SD-WAN architectures simplify the securing of branch-to-branch connectivity natively. Security management of branch-to-branch tunnels in traditional or hybrid WAN, in contrast, are much trickier—and cumbersome.
An SD-WAN architecture overlays the traditional or hybrid WAN infrastructures and automatically locates the software or hardware nodes at each location and in the cloud. Then, based on policies defined by the operator, the SD-WAN steers the traffic along the best path the traffic and selects the best path to ensure data moves along the fastest route.
SD-WAN architecture is standards-based and open, so companies don’t have to invest in expensive proprietary networking solutions to implement SD-WAN—operators simply need an SD-WAN controller—which acts as a “funnel point” to collect, share and information—at the central point and SD-WAN software—where the operational intelligence resides—at the edge.
Plus, it can run over any networking infrastructure. But perhaps its biggest benefit is the technology’s ability to manage entire WAN structures from one central location. Using SD-WAN architecture, a company can monitor and control the data traffic and policies of all of its branch offices, with the ability to provide secure and positive application and user experiences. It also has the intelligence to reroute data traffic around networks that are offline or experiencing slow service.
When it’s time to update or upgrade your traditional MPLS WAN, it’s important to understand the differences between SD-WAN architecture and hybrid WAN. Both have their advantages, but only one offers true application intelligence and central management capabilities. If your company is looking for high availability with an application-driven WAN, SD-WAN is the answer.