Designing and building a highway with state-of-the-art traffic management tools, lighting systems and maintenance capabilities is a heck of an achievement. But it doesn’t mean much until you open it up to cars and trucks and semis.

Since 2014, we’ve been designing and building a radically new type of network. It’s a network built on software. Just as consumers replaced their bulky CD players and point-and-shoot cameras with apps on their phones, we’ve been replacing specialized network equipment with apps running on standard servers.

Our public goal was – and is – to virtualize 75% of our network functions by 2020. We’re on track. The highway is almost complete.

But with most of the concrete poured and the lights installed and the stripes painted, the real test was always going to be how it all responded when the rubber met the proverbial road, when actual network traffic started flowing over this software-defined network.

While we’ve been ramping up for some time, we’re now at a major inflection point: 75% of the data traffic running through the multiprotocol label switching (MPLS) tunnels, which connect the core elements of our network together, is now under SDN control. Think of the tunnels as the interstates of our network that connect major cities and regions of the country. While the tunnels aren’t the only part of our network, they are the element that will benefit the most from software-defined networking.

This is a huge deal. While we’re not done yet, this proves that this model that we designed works.

What does this mean for our customers?

SDN allows to us to move traffic around seamlessly to parts of the network that might be under-used as demand fluctuates (say, as people get home from work and fire up their video streaming apps).

SDN also gives us much greater visibility into potential network problems in a single interface. In the network world, “Layer 1” refers to the physical components, such as the network interface cards in the servers carrying our traffic. “Layer 3” is the network itself. So by integrating layer 1 and layer 3, we can instantly spot both hardware problems – such as a network card that might be about to fail – as well as software issues – such as a cybersecurity threat – and SDN control systems route around those anomalies and ensure our customers enjoy uninterrupted service.

With 5G, our expectations of what a network can do are changing fast. Edge computing, for example, means that we’re moving compute capabilities into the network, closer to our users. That means developers can now create high-performance applications built around 5G’s speed and low latency that reside between the device and the data center. Our SDN technology makes it much easier to deploy and maintain edge capabilities. For 5G to reach its full potential, SDN will be critical.

We’re not done with the construction yet. But this milestone is a huge win for us and, most importantly, for our customers.