SD-WAN has become the most disruptive network technology on the market today, but it has yet to supplant MPLS for most large enterprises, according to a report from Avant published this week.

Avant's SD-WAN report — which polled 300 U.S.-based enterprise decision-makers from manufacturing, financial services, healthcare, e-commerce, and consulting services — explored how rapidly the market is transitioning from legacy solutions to the newer technology that is replacing or supplementing it.

Avant used the data collected from these surveys to develop what it calls a rate of disruption index. Based on this data, the report ranked SD-WAN the most disruptive networking technology of 2019 followed by universal communications-as-a-service and cloud infrastructure.

Avant found a diverse spread of capabilities driving SD-WAN adoption. According to responders, auto failover and redundancy, simplified management, and cost savings over MPLS were the top three.

However, Avant notes that smaller companies with between 250 and 500 employees were far more drawn to cost savings than any other value category.

When Avant looked a the industries where SD-WAN was seeing the fastest rate of adoption, consulting and business series saw the highest rate of disruption, while e-commerce and healthcare posed the lowest rate of disruption.

"It is Avant's belief that SD-WAN will continue to make ongoing incursions into the higher-end enterprise, beginning at remote offices, and other edges of the network, and then reaching steadily closer toward the core," the report reads.

One of SD-WAN's core promises is to reduce costs by shifting bandwidth off of — and in some cases eliminating the need for — expensive MPLS connections. But while more than half of companies surveyed reported that cost savings over MPLS was a key concern, Avant found the majority were still split on whether to keep or replace their MPLS connections in favor of SD-WAN.

Roughly 40% of those surveyed said they planned to use a hybrid solution that combines the two.

Here Avant notes a distinct split between small-to-medium size business and large enterprises with $1 billion-plus in annual revenues. Avant found 53% of large businesses planned to continue and even increase their investments in MPLS, while smaller businesses were displacing MPLS much more quickly.

According to Nate Grinnel, vice president of global sales at Cybraics who was cited in the report, says many smaller enterprises were quicker adopters of cloud technologies making it far easier for them to do away with MPLS at the edge.

Security in the SD-WAN space also remains an ever-present concern for enterprises.

Of those surveyed, Avant found more than 74% expressed fear that a cyberattack would cost them their job, while fewer than half believed their companies were prepared to combat such an attack.

Avant notes that while many SD-WAN offerings include firewalls, site-to-site encryption, application policy control, segmentation for VLANs, and split tunneling, how vendors deliver these security tools varies wildly. For some vendors security is a core component of their offerings, for others a third-party security solution is simply bolted on.

Avant notes that many vendors claim their SD-WAN is interoperable with third-party security tools — meaning enterprises can get away with keeping their existing firewalls and other security gear. But some play together better than others.

The survey found 54% of customers entering the SD-WAN discussion were uncertain how to approach security.