Computers Are Your Future Eleventh Edition Chapter 7: Networks: Communicating & Sharing Resources Copyright © 2011 Pearson Education, Inc. Publishing as

Computers Are Your FutureEleventh Edition

Chapter 7: Networks: Communicating & Sharing

Resources

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 1

2

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic,

mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America.

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Networks: Communicating & Sharing Resources


Objectives

Understand basic networking concepts.

Discuss the advantages and disadvantages of networks.

Distinguish between peer-to-peer (P2P) and client/server local area networks (LANs).

Define topology and understand how the three LAN topologies differ.

4Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Objectives

Explain the importance of network protocols.

Name the most widely used LAN protocol and its versions.

Identify the special components of a wide area network (WAN) that differentiate it from a LAN.


Objectives

Contrast circuit-switching and packet-switching networks and explain their respective strengths and weaknesses.

Identify the options, components, configuration, and maintenance of a home area network (HAN).


Network Fundamentals

A network links multiple computer systems to enable them to share data and resources.

Categories of computer networks for business and organizations: Local area network (LAN) Wide area network (WAN)





LAN Uses cables, radio waves, or infrared

signals Links computers in a limited geographic

area WAN

Uses long-distance transmission media Links computer systems a few miles or

thousands of miles apart The Internet is the largest WANCopyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 9


Communication devices convert data into signals to travel over a medium. Computers Modems Routers Switches Network interface cards

(NICs)Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 10


A node is any device connected to a network.

Network interface card (NIC) An expansion board or adapter that

provides a connection between the computer and the network

Notebook computers have wireless NICs



Routers Connect two or more networks Determine the best route to transmit

data Switches

Filter and forward data between nodes

Are similar to routers but work within a single network



Wireless access point (WAP) Receives and

transmits radio signals

Joins wireless nodes to a wired network


Network Fundamentals File server

High-speed computer that provides program and data files to network users

Contains the network operating system (NOS)

File directories for file and resource location

Computerized software update distribution

Internet services support Protection of services and data Access to connected hardware by

authorized users


Advantages & Disadvantages of Networking

Networking Advantages

Hardware cost reduction Sharing of information, data, and applications Data management centralization Linking of people

Disadvantages Loss of autonomy Lack of privacy Security threats Loss of productivity


Peer-to-peer (P2P) networks Share files without a file server Are easy to set up Are best used for home or small

offices with no more than 10 computers

Do not require a network operating system

Can be slow if there are too many users

Security is not strong


Local Area Networks


Peer-to-peer (P2P) networks

Local Area Networks

Client/server networks Made up of one or more file servers

and clients (any type of computer) Client software enables requests to be

sent to the server Wired or wireless connections Do not slow down with heavy use


Local Area Networks

Virtual private network Operates over the Internet Is accessible by authorized users for

quick access to corporate information Uses secure, encrypted connections

and special software


Local Area Networks

Local Area Networks

LAN topologies Network topology is the physical

design of a LAN. Topology resolves contention, the

conflict that occurs when two or more computers on the network attempt to transmit at the same time.


LAN topologies Bus topology

Practical for home or small office One node transmits at a time

Star topology For office buildings, computer labs, and

WANs Easy to add users

Ring topology For a division of a company or one floor Not in common use today


Local Area Networks


Local Area Networks


Local Area Networks


Local Area Networks

LAN protocols Protocols are the standards used by

networks to permit communication between network-connected devices.

A network’s protocol suite contains the protocols of the network and specifies its network architecture, or how the network works.


Local Area Networks

Local Area Networks

LAN protocols Network layers divide architecture

for separate treatment. Each network layer can operate and be

governed by its own protocols. The vertical arrangement of network

layers is called a protocol stack.


Local Area Networks

LAN protocols LAN technologies

Ethernet is the most-used LAN protocol. The most popular versions are Ethernet star

networks, which use twisted-pair wiring and switches.

Wi-Fi Uses radio waves to provide a wireless

LAN standard at Ethernet speeds Needs a central access point, which could

be a wireless routerCopyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 27

Wide Area Networks

Point of presence (POP) WAN connection point used to obtain

access to the WAN Wired or wireless

Backbones High-capacity WAN transmission lines gigaPoP (gigabits per second

point of presence) transfers data exceeding 1 Gbps


Wide Area Networks

WAN protocols Internet protocols

Transmission Control Protocol (TCP) Defines how Internet-connected computers can

exchange, control, and confirm messages Internet Protocol (IP)

Provides a distinct identification to any computer connected to the Internet: the IP address

TCP/IP Together, they define how the Internet works.


WAN protocols Circuit switching

Used by the public switched telephone networkto send data over a physical end-to-end circuit

Provides a direct connection between devices Packet switching

Used for computer communication Divides and sends outgoing messages as

packets, which are reassembled upon receipt More efficient and less expensive than circuit

switching


Wide Area Networks


Wide Area Networks


Wide Area Networks


Wide Area Networks


Wide Area Networks

Wide Area Networks

WAN applications: E-mail, conferencing, document exchange, remote database access LAN to LAN Connections Transaction Acquisition


Home Networks

Wired Home Networks Ethernet networks link computers

with a switch or router.


Home Networks

Wireless Home Networks Wi-Fi is the wireless standard.

Uses radio signals Communicates through network access

points Needs wireless adapter or router


Home Networks

Setting up a home network Planning

Select technology Purchase equipment and firewall software

Configuring a wired network Connect each computer to the router Plug printer, scanner, etc., into a

computer


Home Networks

Setting up a home network Configuring a wireless network

Connect each node to wireless router with a wireless adapter

Connect DSL or cable modem to wireless router

Maintenance and support Minimal maintenance required Unplug power source from router and

other peripherals and restart computer to correct problems


Home Networks

Future of home networking Control household appliances. Protect homes with security systems. Manage home network events

through central control units in new homes.

Utilize wireless systems.


Summary

Computer networks of two or more linked computers share resources and exchange data.

The two main types of networks are local area networks (LANs) and wide area networks (WANs).

There are advantages and disadvantages to using a computer network.


Summary

42Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Two main categories of LANs are peer-to-peer (P2P) and client/server.

Topologies of a LAN include the bus topology, the ring topology, and the star topology.

Protocols define the manner in which network devices communicate.

Summary

The Ethernet is the most popular LAN protocol.

Distinguishing components of a WAN, as compared with a LAN, are its point of presence (POP) and backbones.

WAN connections may be made through analog telephone calls or digital hookups.


Summary

The technologies on which WAN protocols are based use either circuit switching (PSTN) or packet switching (the Internet).

Wired home networks use Ethernet cable, and wireless home networks rely on Wi-Fi radio signals.


Documents

Computers Are Your Future Eleventh Edition Chapter 7: Networks: Communicating & Sharing Resources Copyright © 2011 Pearson Education, Inc. Publishing as