Sharing the Network: From Circuit Switching to Packet Switching (The Hitchhiker's Guide to Computer Networks)
Prelude ... From Circuit Switching to Packet Switching The simplest approach for two people to communicate over long distances is to connect them through a dedicate physical wire. However, how would we scale that model to a million people that individually want to be able to communicate with everyone else? One approach is to extend wires between all pairs of users, requiring hundreds of billions of wires. This is definitely not a good way to design a network. So what's wrong with that design? First, it is unlikely that every single person in that network will want to talk to everyone else at the same time. This means that we can use fewer wires. Second, not all connections are created equal. Longer wires cost a lot more money than short ones. Our design should have short wires whenever possible. Also it will be nice if the cost of extending long wires is shared between multiple users at the same time. Let's revisit our connection strategy. Rather than extending wires betwe...