The internet is going private. It’s also grown to 138 Tbps of capacity

The world is still sucking down bandwidth like it’s an elixir of the gods, with global bandwidth demand reaching 138 Tbps in 2013, a 4.5 fold increase from the 30 Tbps of capacity from five years before. But it’s the mix of that growth that’s worth noting, according to a report out Wednesday from Telegeography.
Traffic on private networks owned by Facebook(s fb), Amazon(s amzn), Google(s goog) and other web giants is┬ádriving the majority of that growth — about 55 percent of it averaged over that five-year period between 2009 and 2013. The remainder comes from public network traffic operated by carriers like AT&T(s t), Comcast(s cmsa), Level 3(s lvlt) and others. Those public carriers still make up most of the traffic, however. From the report:

Internet backbones remain the primary users of international bandwidth, accounting for 75 percent of demand in 2013. However, the drivers of international bandwidth demand are changing. As private network operators, including large content providers like Google, Microsoft, and Facebook, expand their internal networks, their bandwidth requirements increasingly exceed those of the largest carriers.

Last year a quarter of international bandwidth was used on private networks, as companies try to figure out how to expand their reach and lower the costs they pay for networking. This has led to a shift in how the internet operates, from connecting users to users to the newer model of linking users to data centers, and data centers to each other, according to Alan Mauldin, a research director at Telegeography.
This trend is driving decisions such as Facebook’s leasing of fiber in Europe and in the U.S. as well as Google’s decision to invest in submarine cables. It’s also leading to economic shifts, as ISPs who play in the transit market like AT&T, Verizon(s vz) and Comcast attempt to use their singular access to last-mile subscribers as a way to drive big companies to pay for network interconnections or transit.
We’ll discuss this topic in greater depth at our Structure conference in San Francisco June 18 and 19th when Craig Labovitz of Deepfield Networks shares some of his data on how the structure of the internet is changing.