Internet communication has become a fundamental part of life. The World Wide
Web contains information about such diverse subjects as atmospheric conditions, crop
production, stock prices, and airline traffic. Groups establish electronic mailing lists so
they can share information of common interest. Professional colleagues exchange business
correspondence electronically, and relatives exchange personal greetings.
Unfortunately, most network technologies are designed for a specific purpose.
Each enterprise chooses hardware technology appropriate for specific communication
needs and budget. More important, it is impossible to engineer a universal network
from a single network technology because no single network suffices for all uses. Some
groups need high-speed networks to connect computers in a single building. Low-cost
technologies that fill the need cannot span large geographic distances. Other groups settle
for a slower speed network that connects machines thousands of miles apart.
For over two decades, a new technology has evolved that makes it possible to interconnect
many disparate physical networks and make them function as a coordinated
unit. The technology, called internetworking, accommodates multiple, diverse underlying
hardware technologies by providing a way to interconnect heterogeneous networks
and a set of communication conventions that makes them interoperate. The internet
technology hides the details of network hardware, and permits computers to communicate
independent of their physical network connections.
The internet technology described in this book is an example of open system interconnection.
It is called open because, unlike proprietary communication systems available
from one specific vendor, the specifications are publicly available. Thus, anyone
can build the software needed to communicate across an internet. More important, the
entire technology has been designed to foster communication among machines with
2 Introduction And Overview Chap. 1
diverse hardware architectures, to use almost any packet switched network hardware, to
accommodate a wide variety of applications, and to accommodate multiple computer
operating systems.
To appreciate internet technology, think of how it has changed business. In addition
to high-speed communication among employees in the office environment, networking
technologies provide instant feedback among the production side of the business,
sales and marketing, and customers. As a result, the speed with which business
can plan, implement, assess, and retool has increased; the change is dramatic.
Web contains information about such diverse subjects as atmospheric conditions, crop
production, stock prices, and airline traffic. Groups establish electronic mailing lists so
they can share information of common interest. Professional colleagues exchange business
correspondence electronically, and relatives exchange personal greetings.
Unfortunately, most network technologies are designed for a specific purpose.
Each enterprise chooses hardware technology appropriate for specific communication
needs and budget. More important, it is impossible to engineer a universal network
from a single network technology because no single network suffices for all uses. Some
groups need high-speed networks to connect computers in a single building. Low-cost
technologies that fill the need cannot span large geographic distances. Other groups settle
for a slower speed network that connects machines thousands of miles apart.
For over two decades, a new technology has evolved that makes it possible to interconnect
many disparate physical networks and make them function as a coordinated
unit. The technology, called internetworking, accommodates multiple, diverse underlying
hardware technologies by providing a way to interconnect heterogeneous networks
and a set of communication conventions that makes them interoperate. The internet
technology hides the details of network hardware, and permits computers to communicate
independent of their physical network connections.
The internet technology described in this book is an example of open system interconnection.
It is called open because, unlike proprietary communication systems available
from one specific vendor, the specifications are publicly available. Thus, anyone
can build the software needed to communicate across an internet. More important, the
entire technology has been designed to foster communication among machines with
2 Introduction And Overview Chap. 1
diverse hardware architectures, to use almost any packet switched network hardware, to
accommodate a wide variety of applications, and to accommodate multiple computer
operating systems.
To appreciate internet technology, think of how it has changed business. In addition
to high-speed communication among employees in the office environment, networking
technologies provide instant feedback among the production side of the business,
sales and marketing, and customers. As a result, the speed with which business
can plan, implement, assess, and retool has increased; the change is dramatic.
No comments:
Post a Comment