Showing posts with label
Data communications and networking.
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Showing posts with label
Data communications and networking.
Show all posts
INTRODUCTION
1970s and 1980s saw a merger of the fields of computer science and data
unications that profoundly changed the technology, products, and
panies of the now-combined computer-communications industry. Al-
though the consequences of this revolutionary merger are still being worked out, it
is safe to say that the revolution has occurred, and any investigation of the field of
data communications must be made within this new context.
The computer-communications revolution has produced several remarkable
facts:
There is no fundamental difference between data processing (computers) and
data communications (transmission and switching equipment).
There are no fundamental differences among data, voice, and video commu-
nications.
Data communications and networking are changing the way wedo business and the way
welive. Business decisions have to be madeever morequickly, and the decision makers
require immediate access to accurate information. Why wait a weekfor that report
from Germany to arrive by mail whenit could appear almost instantaneously through
computer networks? Businesses today rely on computer networks and internetworks.
But before weask how quickly wecan gethooked up, weneed to know how networks
operate, what types of technologies are available, and which design best fills which set
of needs.
What is the Internet?
In this book we use the public Internet, a specific computer network (and one which probably most readers have used), as our
principle vehicle for discussing computer networking protocols. But what is the Internet? We would like to give you a one-senten ce
definition of the Internet, a definition that you can take home and share with your family and friends. Alas, the Internet is ve ry
complex, both in terms of its hardware and software components, as well as the services it provides.
A Nuts and Bolts Description
Instead of giving a one-sentence definition, let's try a more descriptive approach. There are a couple of ways to do this. One w ay is
