The problems SD-WAN originally set out to solve are completely different from the problems SD-WAN is solving today, VMware’s Craig Connors said.

Connors, a 14-year veteran of the burgeoning SD-WAN market, helped build SD-WAN products at Talari, Cisco, and VeloCloud, which VMware acquired in 2017. He now serves as VP and CTO of SD-WAN and secure access service edge (SASE) at VMware.

Looking back, Connors said SD-WAN started out as a way to use the internet as an alternative to expensive MPLS links.

“I think one of the challenges we had during the Talari days was trying to convince people that it was a problem that needed to be solved,” he said. “People were very concerned that we were trying to automate their jobs away.”

This began to change as technologies like unified communications-as-a-service and cloud computing began to see adoption. Suddenly, there was an opportunity for SD-WAN to make managing this complexity a little easier, Connors said.

SD-WAN’s potential to address this complexity began to take off as more vendors began entering the market between 2012 and 2014. “So when you got Viptela, and VeloCloud, and CloudGenix all at the same time, I think that's when SD-WAN really formed as an industry,” Connors said. Today, “we have 60 to 70 vendors claiming to do it.”

According to Connors, network complexity helped to boost the adoption of SD-WAN more than anything, adding that two of the biggest contributors in the early days were voice-over-IP (VoIP) and cloud computing.

“Voice was a huge driver because it was something where the reliability of the network became absolutely critical in a way that it wasn’t before for transactional applications,” he said. “There, if you had a network hiccup, it wasn’t the end of the world, but with VoIP, and quickly followed by video collaboration, network reliability became critical for running the business.”

Connors recounted one of VeloCloud’s first large customers, an auto parts retailer, which suffered from dropped calls.

“It was an auto parts retailer telling me that when someone calls us about a part and the phone call drops or they’re garbled and they can’t hear the person on the other end, they don’t hang up and call back, they hang up and call another auto parts store, and they don’t come back,” Connors recalled.

To address this challenge, VeloCloud deployed SD-WAN appliances to the five stores with the most dropped calls. “They went from having 15 or 20 problem calls a day to having zero at those five stores,” Connors said, adding that the chain now has more than 4,000 SD-WAN devices in operation.

As enterprises began shifting applications from the corporate data center to the public cloud, Connors said SD-WAN was also well positioned to provide seamless connectivity to those workloads, where traditional networking practices were not.

“The biggest value is not just the SD-WAN product that you built in the beginning, but the fact you’ve built this extensible fabric that can easily be molded to solve these new emerging use cases,” Connors said.

Today, it's not uncommon for SD-WAN platforms to feature integrated security, application-level quality of service, and other capabilities like artificial intelligence operations.

The integration of security and the rapid shift to remote work has given rise to the next phase of SD-WAN’s evolution: what Gartner calls secure access service edge (SASE). First coined in August 2019, the product category blends together elements of SD-WAN, security, and edge compute into a single cloud-delivered offering.

But while the security features encompassed by SASE — zero trust network access, secure web gateway, cloud access security broker, and firewall-as-a-service — can help address the access and security challenges faced by remote workers, Connors doesn’t see SD-WAN appliances going away anytime soon.

He said in the early days of the pandemic, SASE was seen as a way to quickly get workers back online and back to work, but as it's droned on, companies have begun accepting remote work as the new reality.

“For some companies, there’ll be no return back to the office, and for other companies, it'll be some sort of hybrid mode,” he said, adding that many vendors are now reassessing how networks should be architected to fit this new reality.

Connors believes SD-WAN will be an integral part of that reassessment.

“We have an insurance company that has 18,000 users that have SD-WAN edges at their homes. We have MD Anderson, which has equipped all of their doctors [with SD-WAN appliances] for telemedicine use cases at home,” he said.

According to Connors, while SD-WAN won't be for everyone, it does offer advantages over a software-based connectivity like secure web gateway, zero trust network access, or virtual private networks. These include on-premises security, application-level quality of service, and the ability to employ multiple WAN links for redundancy.

Looking to the future, Connors expects SD-WAN and SASE will play an increasingly important role for developers building applications at the edge of the network.

Just like with the rise of the public cloud, enterprises are increasingly distributing applications to the edge of the network. And with the shift to more distributed architectures, Connors said applications are becoming harder to monitor, manage, and secure.

He added that the distributed nature of SASE presents itself as an opportunity to address these challenges directly and provide customers with a framework on which to run their workloads. “I think SASE and SD-WAN will play a really important role in edge computing,” he said.