Overview of Network Communications

Despite all its other merits, the rapid embrace of Java by the computing community is primarily due to its powerful integration with Internet networking. The Internet revolution has forever changed the way the personal computer is used, empowering individuals to gather, publish, and share information in a vast resource with millions of participants . Building on this foundation, Java could be the next major revolution in computing.

The Java execution environment is designed so that applications can be easily written to efficiently communicate and share processing with remote systems. The standard Java API within the java.net package provides much of this functionality. As a foundation for this chapter on Java and network communications, there are some fundamentals that should be understood before the discussion goes too far. The fundamentals revolve mainly around the design of the Internet network protocol suite: TCP/IP.

TCP/IP is a suite of protocols that interconnects the various systems on the Internet. TCP/IP provides a common programming interface for diverse and foreign hardware. The suite supports the joining of separate physical networks implementing different network media. TCP/IP makes a diverse, chaotic , global network such as the Internet possible.

Models provide useful abstractions of working systems, ignoring fine detail while enabling a clear perspective on global interactions. Models also facilitate a greater understanding of functioning systems and provide a foundation for extending that system. Understanding the models of network communications is an essential guide to learning TCP/IP fundamentals. Although there are several communication protocols that are used to communicate over the Internet and intranets , TCP/IP and UDP are the focus in this chapter.