Business Data Communication Networking - c01.pdf

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001-038_fitzg01_p1.qxd 7/5/06 6:10 PM Page 1
PART 1
INTRODUCTION
Courtesy Cisco Systems, Inc.
Network equipment from Cisco Systems, Inc.
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CHAPTER 1
INTRODUCTION TO DATA
COMMUNICATIONS
Fundamental Concepts
Network Technologies
Application Layer
LAN WLAN
Backbone
Transport Layer
Network Layer
Data Link Layer
Physical Layer
WAN
Internet
M
k
Network Management
The Three Faces of Networking
3
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CHAPTER 1
INTRODUCTION TO DATA COMMUNICATIONS
T HIS CHAPTER introduces the basic concepts of data communications and shows
how we have progressed from paper-based systems to modern computer networks. It
begins by describing why it is important to study data communications and how the
invention of the telephone, the computer, and the Internet has transformed the way we
communicate. Next, the basic types and components of a data communication network
are discussed. The importance of a network model based on layers and the importance of
network standards are examined. The chapter concludes with an overview of three key
trends in the future of networking.
OBJECTIVES
Be aware of the history of communications, information systems, and the
Internet
■
Be aware of the applications of data communication networks
■
Be familiar with the major components of and types of networks
■
Understand the role of network layers
■
Be familiar with the role of network standards
■
Be aware of three key trends in communications and networking
■
CHAPTER OUTLINE
INTRODUCTION
A Brief History of Communications in North America
A Brief History of Information Systems
A Brief History of the Internet
DATA COMMUNICATIONS NETWORKS
Components of a Network
Types of Networks
NETWORK MODELS
Open Systems Interconnection Reference Model
Internet Model
Message Transmission Using Layers
NETWORK STANDARDS
The Importance of Standards
 
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INTRODUCTION
The Standards-Making Process
Common Standards
FUTURE TRENDS
Pervasive Networking
The Integration of Voice, Video, and Data
New Information Services
IMPLICATIONS FOR MANAGEMENT
SUMMARY
INTRODUCTION
Over the past few years, it has become clear that the world has changed forever. We are
now in the Information Age—the second Industrial Revolution, according to John Cham-
bers, CEO (chief executive officer) of Cisco Systems, Inc., one of the world’s leading net-
working technology companies. The first Industrial Revolution revolutionized the way
people worked by introducing machines and new organizational forms. New companies
and industries emerged and old ones died off.
The second Industrial Revolution is revolutionizing the way people work though
networking and data communications. The value of a high-speed data communication net-
work is that it brings people together in a way never before possible. In the 1800s, it took
several weeks for a message to reach North America by ship from England. By the 1900s,
it could be transmitted within the hour. Today, it can be transmitted in seconds. Collapsing
the information lag to Internet speeds means that people can communicate and access in-
formation anywhere in the world regardless of their physical location. In fact, today’s
problem is that we cannot handle the quantities of information we receive.
Data communications and networking is a truly global area of study, both because
the technology enables global communication and because new technologies and applica-
tions often emerge from a variety of countries and spread rapidly around the world. The
World Wide Web, for example, was born in a Swiss research lab, was nurtured through its
first years primarily by European universities, and exploded into mainstream popular cul-
ture because of a development at an American research lab.
One of the problems in studying a global phenomenon lies in explaining the differ-
ent political and regulatory issues that have evolved and currently exist in different parts
of the world. Rather than attempt to explain the different paths taken by different coun-
tries, we have chosen simplicity instead. Historically, the majority of readers of previous
editions of this book have come from North America. Therefore, although we retain a
global focus on technology and its business implications, we focus exclusively on North
America in describing the political and regulatory issues surrounding communications
and networking. We do, however, take care to discuss technological or business issues
where fundamental differences exist between North America and the rest of the world
(e.g., ISDN [integrated services digital network]) (see Chapter 9).
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