Networking Bible

Chapter 9. Routing, Switching, and Bridging

IN THIS CHAPTER

• Circuit versus packet switching

• Hubs, repeaters, bridges, routers, and gateways

• Routing methods

• Anonymous communication with onion routers

Networks require connection devices that can create circuits. Common connection devices such as hubs, bridges, switches, routers, and gateways are described and compared with one another. This chapter explains the two broad categories of networks: circuit switched and packet switched. A circuit is a defined path between two endpoints. Circuit switched networks are stateful and can be described in terms of endpoints and a path. Data travels over the circuit and arrives in sequence. Packet switched networks are stateless. They have endpoints, but the path varies for individual packets based on conditions.

Switching devices can be categorized by the highest level in the OSI data model that they operate on. Hubs and repeaters are the simplest devices; they are simply physical connections. Bridges are devices that span two different network segments, but do not provide protocol translation. A router can connect two different types of networks. Switches and gateways are general terms that describe a variety of different systems.

Circuit versus Packet Switching

Broadly speaking, there are two types of switched networks in use: circuit switched and packet switched. A circuit switched network is defined by a physical or virtual circuit (or connection) that connects two endpoints and has a certain circuit ...