Do you know what the Internet looks like? Odds are you have no idea what path the data transmitted to and from your computer takes to get from point A to point B.

It’s hard to imagine, but until recently, neither did anyone else. Since private companies laid most of the long-haul fiber in this country, no single entity had a really clear idea of the big picture. Thanks to a map produced by a team led by Paul Barford, a computer science professor at the University of Wisconsin–Madison, we now know where all the fiber actually is.

To create the map, Barford’s team spent four years piecing together data from private Internet Service Providers (ISPs) and from federal, state, and local governments. The resulting map actually looks much the way you might expect: fiber routes create a clear outline of the U.S., and if you know a little geography, it’s easy to identify some of the major intersections: Atlanta, Dallas, Denver, Salt Lake City, and so on. The authors also note that in many cases fiber routes correspond neatly with road and rail infrastructure.

Why is this important?
The authors’ goal when compiling this map was to help strengthen our broadband infrastructure by looking for weaknesses. Knowing where infrastructure resources are located makes it easier to predict the effects of disruption to physical pieces of Internet infrastructure on our Internet access. For example, 19 different ISPs share the fiber links between Phoenix and Tucson, Ariz., Salt Lake City and Denver, and Philadelphia and New York City.

It’s easy to see how a problem with these portions of the network could create connectivity issues for a huge number of users. The authors point out that the Federal Communication Commission’s (FCC) decision to reclassify ISPs as Title II carriers likely means there will be an increase in sharing existing long-haul fiber resources. But that also means an increase in risk, as ISPs seek to minimize construction costs.

The paper gets into some pretty deep math to provide specific examples of how we can make infrastructure improvements. But the authors also offer some more general recommendations:

“Risk and latency (i.e., propagation delay) can be reduced by deploying new links along previously unused transportation corridors and rights-of-way. In particular, focusing on a subset of high-risk links is sufficient to improve the overall robustness of the network to failures.”

What are the odds of wide-scale failure?
In California, a series of acts of sabotage against buried Internet fiber have resulted in ongoing disruption of online networks, sometimes affecting tens of thousands of customers at a time. Severing physical fiber connections does more than make it impossible to look at funny cat pictures: in the California attacks, and another attack in Arizona, credit card readers and fiber-based phone systems, including 911 call centers, have also been taken offline.

Fortunately, these attacks seem to be little more than vandalism. Imagine the effects of the Internet going down nationwide and you can see why our Internet infrastructure would make a tempting target for terrorism. The more services we move to fiber, the more we rely on the Internet — and the greater the consequences when something goes wrong.

The U.S. Department of Homeland Security thinks information used to create the map is important enough to make the data available to public and private research groups that can make concrete policy recommendations for infrastructure upgrades.

Why You Should Care
If this work does produce physical improvements to broadband infrastructure, as the authors intended, your Internet access could get faster and more reliable. It will be better able to cope with challenges ranging from natural disasters to everyday heavy bandwidth demands.

While you may not be able to do much for the Internet as a whole, you can easily improve your little corner of it. Enter your ZIP code below to see how much better going online can be.

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