Tubes: A Journey to the Center of the Internet

The title "tubes" comes from a quote from the late Senator Ted Stevens who described the internet as "a bunch of tubes." In this book Andrew Blum travels the world to see the physical structures that make up our modern internet.

He starts with the story of his local internet going down because of a squirrel chewing on cables. He then goes on to describe the structure of the internet. He sees the massive switching centers, undersea cables and even data centers. The "last mile" connections from the fiber to the individual cable-modem was harder to come by, but he was able to end with some basic details of how the network finally reached his house.

The concept of peering was interesting. The internet is made up of a number of different networks. These networks all operate on their own. They must be joined somewhere to the outside world. Often this linkage will be in a big city, so you might have all traffic between two networks in Minnesota routed through Chicago. This networks may later decide to link themselves, allowing traffic to pass directly between them.

The internet is also highly redundant and decentralized. There are multiple paths to reach most destinations. This paths are typically not contained in a central location, but instead contained in individual routers. The global backbones help provide fiber-optic cable to the world.

The book was an eye-opener in the physical world of the internet. The one open question that I had was "who gets paid and who does the paying?"