Web Application Architecture: Principles, Protocols and Practices, 2nd Edition

Chapter 2. Core Internet Protocols

IN THIS CHAPTER

• TCP/IP

• Telnet

• Electronic mail

• Messaging

• Security and encryption

• FTP and file server protocols

• And then came the web ...

OBJECTIVES

• Offer a historical perspective on TCP/IP.

• Explain the client-server paradigm.

• Provide an overview of key Internet protocols and application services that predate the web.

• Show how these protocols and services provided the foundation for HTTP and the web.

As we mentioned in the previous chapter, Tim Berners-Lee did not come up with the worldwide web in a vacuum. The web as we know it was built on top of core Internet protocols that had been in existence for many years. Understanding the ideas behind those underlying protocols is important for the discipline of building robust web applications.

In this chapter, we examine the core Internet protocols that make up the TCP/IP protocol suite, which is the foundation for the web protocols that are discussed in Chapter 3. We begin with a brief historical overview of the forces that led to the creation of TCP/IP. We then go over the layers of the TCP/IP stack, and show where various protocols fit into it. Our description of the client-server paradigm used by TCP/IP applications is followed by discussion of the various TCP/IP application services, including Telnet, electronic mail (e-mail), message forums, live messaging, and file servers. While some of these protocols and services may be deprecated, if not obsolete, knowledge of how they work and what they do provides critical ...