Chapter 1: Introducing TCP/IP

Exam Objectives

Understanding the purpose of TCP/IP

Revealing the components of TCP/IP

Exposing the OSI reference model

Understanding the function of each layer in the OSI model

Examining data encapsulation

Comparing differences in the DoD and OSI models

In almost every aspect of our daily computing lives, we are communicating, researching, and relying on the Internet, a culmination of some of the finest inventions ever conceived. From the humble beginnings of the telephone and telegraph to radio broadcasts and computers, the Internet has allowed us to “get connected.” From online banking to online dating, more than 1.5 billion users use this great tool for education and entertainment, conducting business, and connecting globally with others. Just as we use speech and more than 6,800 different languages to transmit thoughts and ideas, this interconnected web of networks also needed its own language for communication. This language is TCP/IP.

Transmission Control Protocol (TCP) and Internet Protocol (IP) are a set of protocols — a standard set of rules that control and enable communication among computers — developed to allow data exchange and sharing of resources across a network. All hosts that speak this same language on the network can understand one another and communicate together. This language, or protocol, defines how messages are formatted and how errors are handled. A networking world without these rules and protocols in place would probably ...

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