The explosive growth of the Internet in no small part is due to the sockets programming interface. This API allows any computers that run TCP/IP to communicate with one another. In this book, the reader will learn how to write programs that communicate over networks by using the sockets interface to the Internet protocols. The sockets interface is widely available under both the Windows and Unix/Linux operating systems, and the reader will learn how to write robust programs that are portable between different systems. The reader will also learn: core protocols in the Internet protocol suite, such as IP, ICMP, IGMP, DHCP, TCP, UDP, HTTP, and Telnet; fundamental principles of networking, such as layering, naming and addressing, multicasting, framing, flow and congestion control, reliable transmission, and connection management; and practical specifics, such as the sockets interface function calls, tools like traceroute and tcpdump, and details about how to configure network interfaces under Windows and Unix. This book assumes some familiarity with the C programming language, and will teach multithreaded programming and useful features of C++, such as classes and exception handling. components communicate across networks, as well as programs that interface with Internet content providers.