The concept of software-defined WAN is breathing new life into the otherwise stale WAN optimization market.
The WAN optimization market was historically focused on optimizing the performance of application traffic flows from a single link. Software-defined WAN, or SD-WAN, is about virtualizing a variety of links, such as MPLS and Internet, and load balancing traffic across these links.
WAN optimization appliances are morphing into SD-WAN products through the inclusion of features such as WAN path control and local link load-balancing capabilities, according to Gartner's latest WAN Optimization Magic Quadrant report.
What SD-WAN can do
WAN optimization tools today quicken response times of critical applications, like voice, over a range of WAN links or mobile connections. The tools also must address application performance problems caused by bandwidth constraints and latency limitations. On top of these functions, businesses are looking to cut costs. This is where SD-WAN comes in.
With a SD-WAN approach, businesses don't necessarily need expensive, private WAN links to handle increasing traffic. Cheaper broadband connections can be used that weren't an option before. While Internet connections don't provide guarantees, SD-WAN appliances can monitor paths and endpoints to understand whether the link is capable of transporting traffic, especially real-time traffic, reliably.
Just as important as cost savings, IT teams are being freed from WAN management because SD-WAN injects intelligence into path selection where it may not have previously existed. SD-WAN tools can monitor and reroute traffic configurations on an ongoing basis, depending on the state of the network. This "hybrid approach" to WAN optimization can include sending traffic over any WAN link a business may have. For example, private WAN links can be used if a broadband Internet link is slow or if users are experiencing jitter. LTE connections can also be used.
"SD-WAN is doing a much better job of creating a more intelligent WAN, with a much better cost-to-performance ratio," Grossner said.
The state of the WAN optimization market
Talari Networks has been pushing the concept of SD-WAN since coming onto the scene in 2008, Grossner said. Vendors like Talari have pressured WAN optimization vendors into including elements of SD-WAN.
This emerging market trend was not lost on the leaders identified in this year's Magic Quadrant. Leader Silver Peak's dynamic path control feature allows IT teams to select between two or more paths based on measurements of latency and packet loss.
Riverbed, along with Cisco, was also listed as a market leader because of its broad WAN optimization portfolio. The vendor, however, has been slow to embrace a WAN approach that includes private and public Internet links -- also known as a hybrid WAN approach, Gartner said. Riverbed's products have WAN path selection capabilities but these are rudimentary, according to the Magic Quadrant report.
Riverbed, which private equity firm Thoma Bravo acquired last year, is expected to pick up the pace now that it has sold off its ADC and storage businesses, Grossner said. "I suspect Riverbed will be focusing on SD-WAN going forward."
The evolution toward SD-WAN has opened the door for startups like Viptela and CloudGenix to compete against traditional WAN optimization leaders. "We have all these new offerings and companies that we didn't have before," Grossner said.
Those companies may not exist for long. Gartner predicts that the market will consolidate over the next two years as the WAN optimization market expands and evolves further.
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