Shlomo Kramer is unusually good at picking startup winners. His Cato Networks is a secure cloud network security service that’s growing fast — and that could cost incumbents like AT&T and Verizon some revenue.

(Read on Forbes)

Kramer has a great track record of startup investing success. He hauled in $740 million from the proceeds of two companies. Globes estimated that his August 2013 sale of Trusteer, an information security service provider, to IBM for “close to $1 billion” yielded Kramer $240 million. Moreover, it estimates that Kramer realized $500 million from selling his stake in Check Point Software, which had a $16.8 billion market capitalization on February 2.

He has made other successful bets in startups that now trade on NASDAQ. In March 2015, Kramer owned a 13.7% stake in Imperva ($1.5 billion market capitalization) and in August 2013 owned 1.5% of Palo Alto Networks ($13.3 billion market capitalization), which would now be valued at $206 million and $200 million, respectively.

But Kramer is not stopping there. In October 2015, he announced Cato’s $20 million financing from U.S. Venture Partners and Aspect Ventures.

Kramer is CEO and co-founder with Gur Shatz, who had bootstrapped the company until 2015. Shatz brings “an extensive background in Cloud-based web applications security and acceleration. Previously, he was the co-founder and CEO of Incapsula, which Imperva acquired in 2014, according to my October 2015 interview with Kramer.

On January 31, Cato announced that it’s growing fast — bookings were up 100% “quarter over quarter,” according to a company statement. And Cato’s growth could come out of the hide of companies like AT&T and Verizon, Kramer explained in a January 29 interview.

That’s because business data traffic has changed and those telecom giants have not adapted their products to the change. “[AT&T and Verizon offer Multi-protocol Label Switching] MPLS which used to be great when the most common traffic pattern was between a remote office and headquarters,” said Kramer.

But today’s traffic is very different. “[An executive might] use his smartphone in a hotel room in Tokyo to access Workday with customer data coming from AWS. The Wide Area Network (WAN) has to be reevaluated over the next five to 10 years to accommodate these changes,” he explained.

Cato believes that its so-called Software Defined (SD-WAN) is a much better solution for customers’ current traffic patterns than the ones offered by AT&T and Verizon. “Cato Cloud securely connects all enterprise locations, people, and physical and cloud datacenters into a global, encrypted and optimized SD-WAN in the cloud. And it offers a migration path from the old to the new.”

SD-WAN is a large market that’s growing quickly. According to IDC, worldwide SD-WAN infrastructure and services revenue will grow at a nearly 70% compound annual rate to reach $8.05 billion in 2021.

The reason for this growth is that SD-WAN is flexible and based in software in the cloud; whereas incumbents offer “a rigid, widget-based solution. We are [borrowing from T-Mobile] the un-carrier,” argues Kramer.

Cato, which Kramer plans to build into a big company, says it’s the market leader in SD-WAN. According to a statement, “Cato Cloud has a larger network footprint than any other global, cloud-based SD-WAN with 39 points-of-presence (PoPs) around the globe, including two locations in China, Beijing and Shanghai, and twice the number of PoPs in North America as its closest competitor.”

But will AT&T or Verizon buy the company to get its technology? After all, 2017 featured two acquisitions of SD-WAN companies. To wit, VMware purchased SD-WAN vendor VeloCloud in November 2017 for an undisclosed amount and Cisco purchased Viptela for $610 million in August 2017, according to SDX Central.

Cato says it has “hundreds of customers with thousands of branch locations across all verticals. Among these is Pet LoversCentre Pte Ltd, an Asian pet products and services retailer which runs “more than 100 sites on Cato Cloud,” according to Cato. David Whye Tye Ng, CEO & Executive Director at Pet Lovers says, “I would recommend Cato to a friend, and that’s a big deal for me to say.”

AT&T argues that its service is great for customers. According to the company, “Virtual Private Networks (VPN) based on MPLS are an excellent option for connecting to cloud-based services because of their private network characteristics, improved levels of connectivity, availability of infrastructure redundancy, capabilities for prioritizing traffic.”

Cato believes that AT&T and Verizon have been slow to deliver their own SD-WAN service. “They have been trying to do what they know, which is to orchestrate big integration projects. But when it comes to offering a carrier cloud, the polite way to describe what they’re doing is ‘it’s perpetually arriving soon,'” said Kramer

Randall Stephenson, CEO and chairman of AT&T, told investors during its first-quarter 2017 conference call that it needs an SD-WAN product in its portfolio. According to Stephenson, “You should assume we’re developing [an SD-WAN] capability ourselves because we think it’s a viable offer down market [for small and medium-sized businesses]. We’re seeing some effect from it and while it’s not material yet, we need to have it.”

Indeed, Fierce Telecom reported that in 2016 AT&T was collaborating with VeloCloud, which VMWare acquired (see above). But that has not stopped AT&T, which SDX Central reported last month is the basis of its SD-WAN offering.

SD-WAN seems to offer businesses a more flexible solution that better meets their needs and requires much less overhead.

This leaves two questions: Will large companies also adopt SD-WAN? Will Cato or AT&T and Verizon dominate that market?