According to Scientific American, the Internet’s infrastructure is, for the most part, hidden. In this “Future of the Internet” report, industry observers notes that in the U.S. there are on the order of one hundred Internet service providers that control the fiber lines and the routers that direct traffic throughout the network. Each of these ISPs has agreements with the others to exchange traffic.
“Each of these ISPs has agreements with the others to exchange traffic. In essence, these agreements say if you move my bits, I’ll move yours. However, all these agreements are not just independent and unregulated, they’re secret. Proprietary corporate information. This makes it impossible to understand how traffic will get redirected when, say, one path fails. It makes it impossible to understand just how strong the overall system is when something goes wrong. It makes it impossible to map the overall structure of the Internet (something intensely frustrating to claffy, whose job it is to map the overall structure of the Internet). And it also makes it difficult to predict how the Internet will grow.”