This chapter is an introduction to the application layer. In the next eight chapters we introduce common client-server applications used in the Internet. In this chapter, we give a general picture of how a client-server program is designed and give some simple codes of their implementation. The area of network programming is a very vast and complicated one; it cannot be covered in one chapter. We need to give a bird’s-eye view of this discipline to make the contents of the next eight chapters easier to understand. | Chapter 15 Application Layer and Client-Server Model CONTENTS CLIENT-SERVER MODEL CONCURRENCY PROCESSES Figure 15-1 Comparison between OSI and TCP/IP CLIENT-SERVER MODEL Figure 15-2 Client-server model Figure 15-3 Client-server relationship CONCURRENCY Figure 15-4 Server types Figure 15-5 Connectionless iterative server Figure 15-6 Connection-oriented concurrent server PROCESSES Figure 15-7 Programs and processes Figure 14-8 Prototype for the getpid function Figure 15-9 A program that prints its own processid Figure 14-10 Prototype for the fork function Figure 14-11 A program with one parent and one child Figure 15-12 A program with two fork functions Figure 15-13 The output of the program in Figure Figure 15-14 A program that prints the processids of the parent and the child Figure 15-15 Example of a server program with parent and child processes | Chapter 15 Application Layer and Client-Server Model CONTENTS CLIENT-SERVER MODEL CONCURRENCY PROCESSES Figure 15-1 Comparison between OSI and TCP/IP CLIENT-SERVER MODEL Figure 15-2 Client-server model Figure 15-3 Client-server relationship CONCURRENCY Figure 15-4 Server types Figure 15-5 Connectionless iterative server Figure 15-6 Connection-oriented concurrent server PROCESSES Figure 15-7 Programs and processes Figure 14-8 Prototype for the getpid function Figure 15-9 A program that prints its own processid Figure 14-10 Prototype for the fork function Figure 14-11 A program with one parent and one child Figure 15-12 A program with two fork functions Figure 15-13 The output of the program in Figure Figure 15-14 A program that prints the processids of the parent and the child Figure 15-15 Example of a server program with parent and child processes | Chapter 15 Application Layer and Client-Server Model CONTENTS CLIENT-SERVER MODEL CONCURRENCY PROCESSES Figure 15-1 Comparison between OSI and TCP/IP CLIENT-SERVER MODEL Figure 15-2 Client-server model Figure 15-3 Client-server relationship CONCURRENCY Figure 15-4 Server types Figure 15-5 Connectionless iterative server Figure 15-6 Connection-oriented concurrent server PROCESSES Figure 15-7 Programs and processes Figure 14-8 Prototype for the getpid function Figure 15-9 A program that prints its own processid Figure 14-10 Prototype for the fork function Figure 14-11 A program with one parent and one child Figure 15-12 A program with two fork functions Figure 15-13 The output of the program in Figure Figure 15-14 A program that prints the processids of the parent and the child Figure 15-15 Example of a server program with parent and child .
