"Using BGP, your networks tells its directly-connected providers that, 'I know the way to these IP addresses, and can get you there in one hop,'" Joffe explained. "Those providers are connected to other networks as well, and begin to tell the world the way to you."

The process continues, with each network's routers describing a pathway to a specific network. Some of those paths may be long -- ten, eleven, even more 'hops' as Joffe described them -- while others may be much more direct, taking fewer hops from one network to another.

"At any time, there are hundreds of different ways to get from Point A to Point B," Joffe said. "So if for some reason there's a disconnection of a nine-hop path, the traffic switches to a path using, for example, 11 hops."

But all that fails when a network refuses to announce to others that it exists.

The kill switch deployed by Egyptian ISPs took effect in a matter of minutes, and was the easiest way for the government to sever connections.