Internet Core Protocols: The Definitive Guide

Images

Throughout this book, a variety of images are used to represent different types of network devices, including hosts, routers, modems, and other infrastructure equipment. In order to minimize any possible confusion, these symbols are shown in the three figures in this Preface to provide a common interpretation throughout the various chapters.

For example, Figure 0.1 shows the common symbols that are used for Token Ring and Ethernet networks, the symbols used for application clients and servers, and a network router.

Figure 0.1. Common symbols used with local area networks

Figure 0.2 shows the symbols that are commonly used to represent wide area networks (WANs), including those that incorporate modems, satellites, microwave radio, and generic WANs (such as Frame Relay or leased-line networks). Notice that the figures used for network routers, application clients, and servers are the same as those used for LAN-based topologies.

Figure 0.2. Common symbols used with wide area networks

Note that sometimes a generic host will be identified using the “Application Client” symbol, indicating that the device is either sending data to or receiving data from another network device, which may be another client or server, indicating that the role played by the devices is irrelevant to the discussion at hand.