The Mechanics of Egypt's Internet Kill Switch

After Egypt shut off its own access to the Internet, people have been speculating about how exactly they did it. A New York Times story today brings us closer to figuring that out. Through interviews with a bunch of engineers, they've pinpointed exactly what happened (at least technically).

After you read their description of the government's move, reread Andrew Blum's piece published here on The Atlantic about the United States' own physical Internet infrastructure. It may not be controlled by our government, but the key interconnection points are increasingly controlled by a few companies (Google, Verizon). Internet choke points matter, as we've seen, and we've got a few of our own to look after.

The attack in Egypt relied on a double knockout, the engineers say. As in many authoritarian countries, Egypt's Internet must connect to the outside world through a tiny number of international portals that are tightly in the grip of the government. In a lightning strike, technicians first cut off nearly all international traffic through those portals.

In theory, the domestic Internet should have survived that strike. But the cutoff also revealed how dependent Egypt's internal networks are on moment-to-moment information from systems that exist only outside the country -- including e-mail servers at companies like Google, Microsoft and Yahoo; data centers in the United States; and the Internet directories called domain name servers, which can be physically located anywhere from Australia to Germany. The government's attack left Egypt not only cut off from the outside world, but also with its internal systems in a sort of comatose state: servers, cables and fiber-optic lines were largely up and running, but too confused or crippled to carry information save a dribble of local e-mail traffic and domestic Web sites whose Internet circuitry somehow remained accessible...

The engineers say that a focal point of the attack was an imposing building at 26 Ramses Street in Cairo, just two and a half miles from the epicenter of the protests, Tahrir Square. At one time purely a telephone network switching center, the building now houses the crucial Internet exchange that serves as the connection point for fiber-optic links provided by five major network companies that provide the bulk of the Internet connectivity going into and out of the country.

Read the full story at the New York Times.