Analysts and industry pundits like to talk about the big-picture, and somewhat esoteric, drivers of the SD-WAN market, but customers seem more focused on the question: What can this do for me today? One of the most popular use cases is to reduce network outages.

Two big research outfits, IHS and IDC, have been looking at the SD-WAN market, and they have some statistics that show it's growing like crazy.

In its first forecast of the SD-WAN market, IDC estimates that worldwide SD-WAN revenues will exceed $6 billion in 2020 with a compound annual growth rate of more than 90 percent over the 2015-to-2020 forecast period.

IDC’s report says the benefits include cost-effective delivery of business applications, meeting the evolving operational requirements of the modern branch site, and improving IT efficiency through automation. It also says enterprises expect to save money on some of their expensive MPLS connections.

Meanwhile, IHS, in a report still being prepared, found that by the end of 2016, 13 percent of North American enterprises will be in live production of the technology, and 62 percent will be in lab trials. And by 2018, 82 percent of respondents expect to be in live production of SD-WAN.

IHS analyst Cliff Grossner discussed the findings while moderating a panel at the recent Open Networking Summit (ONS). He said the top driver for SD-WAN is a desire by enterprises to provision new branch sites rapidly. They also want SD-WAN to deliver improved application performance and to layer-in security. In addition, survey respondents say they expect cost savings from the technology.

Customers seem most interested in concrete use cases. Recently, Citrix announced its CloudBridge SD-WAN product; and its first customer, The Watershed, said it uses it to avoid blackouts and brownouts.

In Grossner's ONS session, entitled “SD-WAN: Early Adopters Share Lessons Learned,” at least one customer that is using the technology had specific, practical reasons for using it.

Roger Bravo, VP of engineering at call center company Teleperformance, said he chose Talari’s SD-WAN in 2011 because it ensures call quality, which is critical to the company’s core business.

With 270 call centers in 62 countries, service continuity was a big challenge for Teleperformance. Even call centers that were paying for redundant MPLS connections would experience call failures if a primary circuit went down, in which case there would be a short outage while the traffic was diverted from one connection to the other.

Bravo said Talari establishes a virtual conduit between the data center and the remote end. “You could put DSL, an Internet pipe, dual MPLS, whatever you choose,” he said. “It sees everything that’s going on in that bandwidth, and it makes intelligent decisions as to which path to send those packets. Any one of those circuits could fail, and that traffic still gets to the other end.”

SD-WAN also helps when bandwidth requirements peak for some reason or when any of the connections require scheduled maintenance.

Bravo said SD-WAN is ideal for industries that can’t tolerate outages.

Kevin Gavin, Talari’s chief marketing officer, says other big verticals for the company include emergency services and, curiously, the legal industry — because lawyers conduct a lot of conference calls, and with billing rates reaching $800 per hour they can’t afford voice outages.