Circuit, Message, and Packet Switching
Robert H. Greenfield · The Internet Encyclopedia · 2004
Abstract Packets and packet switching were invented to utilize effectively, i.e., to multiplex, digital networks. We easily grasp the concepts of circuit switching, such as a voice telephone call, and message switching, such as the paper‐based postal system, because there are many common and historical examples. In recent decades, we've discovered that digital techniques for transmission and switching information are far superior, faster, cheaper, and less error prone than the analog techniques devised in earlier times. These digital methods allowed for the invention of packets and packet switching, thereby making digital technology even more effective. Networks are built in layers. First, we look at some important layering models for different kinds of digital networks. We also mention how addresses fit into our layering schemes. Next, we briefly describe circuit and message switching before surveying the primary topic of packet switching.