1 Introduction 1 1.1 Networks, Packets, and Protocols 1 1.2 About Addresses 4 1.3 About Names 6 1.4 Clients and Servers 6 1.5 What Is a Socket? 7 1.6 Exercises 8 2 Basic Sockets 9 2.1 Socket Addresses 9 2.2 TCP Sockets 15 2.2.1 TCP Client 16 2.2.2 TCP Server 21 2.2.3 Input and Output Streams 25 2.3