Data communication and networking by Behring a forouzan 4th edition
Data communications
and networking may be the fastest growing technologies in our culture
today. One of the ramifications of that growth is a dramatic increase in
the number of professions where an understanding of these technologies
is essential for success and a proportionate increase in the number and
types of students taking courses to learn about them.
Data
communications and networking are changing the way we do business and
the way we live. Business decisions have to be made ever more quickly,
and the decision makers require immediate access to accurate
information. Why wait a week for that report from Germany to arrive by
mail when it could appear almost instantaneously through computer
networks? Businesses today rely on computer networks and inter-networks.
But before we ask how quickly we can get hooked up, we need to know how
networks operate, what types of technologies are available, and which
design best fills which set of needs.
The development of the personal
computer brought about tremendous changes for business, industry,
science, and education. A similar revolution is occurring in data
communications and networking. Technological advances are making it
possible for communications links to carry more and faster signals. As a
result, services are evolving to allow use of this expanded capacity.
Research
in data communications and networking has resulted in new technologies.
One goal is to be able to exchange data such as text, audio, and video
from all points in the world. We want to access the Internet to download
and upload information quickly and accurately and at any time.
This
part addresses four issues: data communications, networks, the Internet,
and protocols and standards. First we give a broad definition of data
communications. Then we define networks as a highway on which data can
travel. The Internet is discussed as a good example of an inter-network (
a network of networks ). Finally, we discuss different types of
protocols, the difference between protocols and standards, and the
organizations that set those standards.
Networks exist so that
data may be sent from one place to another- the basic concept of data
communications. To fully grasp this project, we must understand the data
communication components, how different types of data can be
represented, and how to create a data flow.
Data communications
between remote parties can be achieved through a process called
networking, involving the connection of computers, media, and networking
devices.
Protocols and standards are vital to the implementation of
data communications and networking. Protocols refer to the rules; a
standard is a protocol that has been adopted by vendors and
manufacturers.
Network models serve to organize, unify, and control
the hardware and software components of data communications and
networking. Although the term “network model” suggests a relationship to
networking, the model also encompasses data communications.
The two
dominant networking models are the Open System Interconnection (OSI)
and the Internet model (TCP/IP). The first is a theoretical framework;
the second is the actual model used in today’s data communications. So,
we will discuss the OSI model to give a general background. We then
concentrate on the Internet model.
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