17.1 Introduction

17.1 Introduction

In this chapter we provide a description of the services provided by TCP for the application layer. We also look at the fields in the TCP header. In the chapters that follow we examine all of these header fields in more detail, as we see how TCP operates.

Our description of TCP starts in this chapter and continues in the next seven chapters. Chapter 18 describes how a TCP connection is established and terminated , and Chapters 19 and 20 look at the normal transfer of data, both for interactive use (remote login) and bulk data (file transfer). Chapter 21 provides the details of TCP's timeout and retransmission, followed by two other TCP timers in Chapters 22 and 23. Finally Chapter 24 takes a look at newer TCP features and TCP performance.

The original specification for TCP is RFC 793 [Postel 1981c], although some errors in that RFC are corrected in the Host Requirements RFC.