CompTIA Network+ Study Guide

Chapter 1. How Networks Work

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In this chapter, you will learn how to:

• Describe how networks work

• Explain the OSI reference model

• Describe the TCP/IP model

Obj. 1.1: Explain concepts related to the Open Systems Interconnection (OSI) reference model

You might have met that person. You at least know the type. Some seemingly impossible technical problem crops up and, after a lot of head scratching, someone suggests, “Call John. He’ll have an idea.”

And he does. Describe the problem to John and he’ll readily have a couple of possible causes for the problem and a few solutions to try.

What makes these “magic troubleshooters” so special? John—or whatever the person’s name is—is not smarter than you or your colleagues. But he knows how things are supposed to work. By understanding the systems, magic troubleshooters can picture the process and imagine where things could have failed or not been implemented properly.

Let’s translate that now into information technology (IT) networking.

Mastering the art of building, maintaining, and fixing networks requires ...