Software-Defined Wide Area Networking (SD-WAN) has become the buzz word in enterprise networking, emerging as a true disruptive technology for enterprises in the cloud era. The rise of SD-WAN has been quite spectacular. Although software-defined networking (SDN) has been talked about for a while, the idea of applying the principles of SDN to the WAN side of the network has emerged only in the last few years as Mike Wood, VeloCloud explains.

Previously, client/server computing was extended across an entire organization using the WAN and had become became the norm: applications and data being stored in the company data center and accessed by branch offices along a hub-and-spoke architecture linking each office to the central data center hub. This made good sense when the bulk of traffic flow was between branch and data center via private lines, with little reliance on what were still ponderous Internet services. With the shift to cloud computing, however, many orgnisations now have a “cloud first” policy requiring an architectural change, while the need to both send and receive high bandwidth traffic via the hub puts an enormous load on the spokes. In addition, network management has required manual configurations to a lot of individual boxes, so even simple adjustments were taking ages. The traditional WAN was sorely in need of upgrade – a challenging exercise using an MPLS based system.

So SD-WAN could not have emerged at a better time. SDN had already revolutionised local area networks and datacentre connectivity, but extending it to the wide area was a different beast. Building predictable service quality over less predictable “best effort” links was one challenge. Another was to reduce delays between nodes often separated by hundreds of kilometres. Above all, there was the challenge of far less standardisation across a geographically dispersed WAN: work is still being done to allow interoperability between different vendors’ equipment, and to allow the use of virtual machine hosting on common off-the-shelf hardware.

However, one of the segments to recognize both the disruptive potential as well as a new opportunity was Service Providers, where SD-WAN is now big news. Last October saw Sprint announce plans for SD-WAN customer trials, AT&T announced two SD-WAN offerings, Complink 1210 was to extend these services to 13 European nations, while TelePacific Communications announced SD-WAN capabilities for their OTT and Ucx unified communications. Meanwhile established router vendors, including Cisco have been attempting to add SD-WAN features into their existing platforms, and Nokia’s Nuage Networks has also joined the trend.

So what is being offered? Eve Crane, Sprint’s Network Solutions’ product marketing manager said they would be working with VeloCloud to offer SD-WANs across their carrier portfolio with virtual network function (VNF) services all the way to edge devices. Whereas large, centrally located enterprise sites have been enjoying high quality cloud services across telco networks, when those cloud services are rolled out to distant branch offices that rely on whatever Internet connections are available, performance had often suffered, with unhappy users wanting to restore in-house application hosting.

Such widely dispersed offices have to take advantage of whatever connectivity is available, often at short notice. MPLS is a good solution, but more agile technologies such as Internet broadband, wireless and LTE are quicker to install and often at much lower cost. What SD-WAN promises is the ability to integrate any number of such private or “best effort” Internet connections seamlessly to ensure better bandwidth and reliability to the branch office, while maintaining required levels of security regardless of the underlying link structure.

Even if the WAN extends across thousands of kilometres, this SD-WAN will make local forwarding decisions based on observed local conditions, such as link quality and throughput and applying business policies in prioritising traffic. The central controller implements software forwarding based not only on centralised policy objectives but also real-time network quality. The routing, priority and security for any application data flow is therefore independent of the actual network transport – whether wired Ethernet, MPLS, wireless, cellular, or a public Internet link. For the VeloCloud SD-WAN, the controller concept is extended to allow continued operation with or without instructions from the controller – this ensures maximum uptime and security, optimized data delivery, and supports service level guarantees.

SD-WANs are proving to be fast, flexible and inexpensive. Cloud-based management tools allow business policy decisions to be easily changed and automated from a central location for maximum efficiency, lowest cost or optimal security. The result is a practical, cost-effective way to extend the full benefits of cloud computing to the very edges of an organisation. It makes it quick and easy to integrate new network services, virtualize services, load-share over multiple different links, simplify configuration and policy management, and optimize application performance and security.

All traffic between the office and the carrier’s edge is encrypted by the system, but customers still concerned about sending critical data via DSL, WiFi or LTE can easily integrate SD-WAN with their trusted security technologies.

According to Eve Crane: “Enterprises can use new or existing Sprint MPLS or broadband Internet connectivity, as well as broadband from other providers.” The carrier manages the SD-WAN across transport vendors to provide an integrated end-to-end solution with the advantages of simplified pricing and billing; flexible management; integrated security and “agnostic” support.

So flexible, agile and secure WAN connectivity is no longer just a option: SD-WAN is the way of the future.

Ask questions, take a look – and be pleasantly surprised.