Software-Defined WAN Benefits

Emerging SD-WAN technologies provide new options for reducing WAN costs and improving performance. Here's how they work, including one that puts a different twist on SD-WAN.

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It used to be that there were two dominant WAN implementation choices that network administrators had for WAN connectivity to remote sites. You either leased WAN connections such as Metro Ethernet or MPLS,  or you built site-to-site VPN tunnels over the Internet. While both options did, and still do work, there is plenty of room for improvement. Let’s take a look at how emerging software-defined WAN technologies will give us fresh new capabilities that will lower costs and improve performance.

SD-WAN routing technologies can aggregate data transport over two or more WAN connections including MPLS, Metro Ethernet, cellular and broadband Internet connections. The types of underlying transport used in hybrid WANs becomes agnostic because SD-WAN technologies create a logical overlay to intelligently route data across multiple paths. Multiple connections can be used simultaneously, eliminating the need to oversubscribe connections that have traditionally functioned in an active/standby manner.

Besides the obvious benefits of WAN link aggregation, next-generation WAN technologies also leverage end-to-end network visibility and feedback in order to improve transmission efficiencies on the fly. SD-WANs can detect the fastest path (or paths) from source to destination in real-time and dynamically re-route packet flows across links to improve performance. Routing decisions are made based on data such as latency, load and types of QoS policies applied.

Another optimization feature found in most SD-WAN technologies is the ability to optimize WAN traffic through the use of caching and advanced compression. Think of it as your typical WAN acceleration appliance, only built directly onto the network. So in a sense, SD-WANs have the ability to roll-up multiple technologies into a single intelligent piece of software that has an end-to-end view to make the best possible data routing and optimization decisions.

Software-defined WAN technologies include Cisco iWAN, Silver Peak Unity, as well as SD-WAN products from companies such as CloudGenix, Masergy, Talari Networks, and Viptela. But if you’re looking for something even more cutting edge, you may want check out a company called Dispersive Technologies.

VDN technology

With other SD-WAN technologies, software is used to make a determination regarding the optimal path from source to destination across two or more dedicated circuits or Internet connections. The network itself still maintains the classic client/network roles, where routing intelligence is handled by strictly by the network. Software supplier Dispersive Technologies and its patented Virtual Dispersive Network (VDN) technology throws that model out the window.

Instead, not only do end devices and servers act as the source and destination of data, they also actively participate in the routing process. Data that is transmitted on the VDN is forced into multiple streams. Each data stream takes a different path, using other clients as route deflectors. Eventually, all the data reaches its final destination where it is decrypted and put back together.

What this means is that a single Internet connection can be used, yet the underlying SD-WAN software can still intelligently load balance and optimize the transmission of data across multiple paths by deflecting data across multiple client deflectors. The software-based VDN overcomes the point A to point B type transmissions found in traditional site-to-site VPN connections.

The same optimization techniques used in hybrid WANs, which measure real-time latency, load and line qualities are also used in a VDN. The main difference is that VDN doesn’t necessarily need two or more aggregate WAN links to form multiple, simultaneous paths.

If you’re looking for ways to slash operational WAN costs, you’re not alone. It’s a considerable expense -- one that's often difficult to justify to non-IT decision makers. It used to be that WANs had to be over provisioned simply because there was no other alternative. Thankfully, there are plenty of networking vendors that are looking into ways for customers to reduce WAN operational costs by allowing us to right-size WAN links.

About the Author(s)

Andrew Froehlich, President, West Gate Networks

President, West Gate Networks

As a highly experienced network architect and trusted IT consultant with worldwide contacts, particularly in the United States and Southeast Asia, Andrew Froehlich has nearly two decades of experience and possesses multiple industry certifications in the field of enterprise networking. Froehlich has participated in the design and maintenance of networks for State Farm Insurance, United Airlines, Chicago-area schools and the University of Chicago Medical Center. He is the founder and president of Loveland, Colo.-based West Gate Networks, which specializes in enterprise network architectures and data center build outs. The author of two Cisco certification study guides published by Sybex, he is a regular contributor to multiple enterprise IT related websites and trade journals with insights into rapidly changing developments in the IT industry.

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