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‘Computer Networks' PDF: Free chapter download

Download this computer networking PDF excerpt from "Computer Networks," a book that addresses the key principles of computer networks. In Chapter 1, Foundation, learn how local and wide area networks (WANs) are now built to connect more than computers.

It is important to lay a foundation before you build a general-purpose computer network. If you're looking to build a  network that has the potential to grow to global proportions and support increasingly diverse applications, first you need to learn what available technologies can help you to reach your specific goals. 

This free networking PDF, "Foundation," Chapter 1 from the Computer Networks: A Systems Approach, Fifth Edition, will teach you what building materials you will need to construct a network from scratch. It explores the requirements that different applications and communities place on the network, introduces network architecture basics and options, discusses the networking and IT groups that should be consulted in network design, examines key elements in computer networks and identifies the key metrics used to evaluate the computer network performance.

Computer Networks: A systems Approach, Fifth Edition After reading the summary below, use the download form above to get the PDF of Chapter 1: "Foundation," from Computer Networks: A Systems Approach, Fifth Edition, by Larry L. Peterson and Bruce S. Davie (Morgan Kaufmann, 2012).

Applications over your network

A network must provide connectivity among a set of computers. While some networks limit the number of connected machines, others grow as large as a global wide area network (WAN). Chapter 1 of Computer Networks: A Systems Approach, Fifth Edition hopes to explain why networks are designed the way they are to help readers better understand how to build a network from the ground up. This computer networking PDF walks you through how to build a network that supports application diversity.

Network requirements to accommodate application needs

Efficiency is the key requirement of computer networks, which is why networks use packet switching as their main strategy. It's too simplistic to view a computer network as simply delivering packets among a collection of computers, however. A network should be thought of as the way to deliver a set of applications distributed over those computers. Success includes both understanding the applications' requirements and recognizing the limitations of the underlying technology. The challenge is to fill the gap between what the application needs and what the technology can provide.

Networks do not remain fixed and must be able to evolve to accommodate technological changes, and networking and IT professionals must be able to manage them. Designing a network to meet those requirements isn't easy. The most basic requirements for a network are that they must provide general, cost-effective, fair and robust connectivity among a large number of computers.

Network architecture as the blueprint

Network architectures are general blueprints that guide the design and implementation of your network. The idea of abstraction, which hides your networking details behind a well-defined interface. The idea of abstraction is to make a model that can capture an important aspect of the system, but the challenge is to identify abstractions that simultaneously provide a service that proves useful in a large number of situations. Abstractions naturally lead to layering. The idea is that you start with the services the underlying hardware offers, then add a sequence of layers, each of which provides a higher level of service. Layering helps IT professionals build a network into more manageable components.

Implementing network software

One of the things that has made the Internet such a success is the fact that software running in general-purpose computers provides so much of its functionality, which means new functionality can be added easily. As a result, new applications and services can deployed in a heartbeat. Knowing how to deploy network software is an essential part of understanding computer networks. Specific instructions and visual representations for both the client and the server can be found in the networking PDF.

Network performance

Naturally, computer networks are expected to perform well, and it's vital to understand the factors that can impact network performance. Network performance is measured by bandwidth and latency. A network's bandwidth is the number of bits that can be transmitted over the network in a certain period of time. Latency is how long it takes a message to travel from one end of a network to the other and is measured in time. Equations found in this chapter can help you properly assess the performance of your computer LAN or WAN network.

To read the full book chapter, download this free computer networking PDF using the form above.

About the book

Computer Networks: A Systems Approach, Fifth Edition, teaches the key principles of computer networks, using the Internet as a primary example to explain protocols and networking technologies. The book encourages readers to think, through a number of perspectives, about how a network can fit into a larger, complex system of interaction.

About the authors: 
Author Larry Peterson is the Robert E. Kahn Professor of Computer Science and Director of the Princeton-hosted PlanetLab Consortium. His research focuses on the design and implementation of networked systems.

Author Bruce Davie is a visiting lecturer at MIT and chief service provider architect at Nicira Networks. As a fellow at Cisco Systems, he led a team of architects responsible for Multiprotocol Label Switching and IP Quality of Service. He is also an active participant in the Internet Engineering Task Force (IETF) and is currently SIGCOMM chair.

©2012 Elsevier Inc. All rights reserved. Printed with permission from Morgan Kaufmann, a division of Elsevier. Copyright 2012. For more information on this title and similar networking books, please visit

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This was last published in June 2012

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