Computer Networks Fundamentals

Computer Networks Fundamentals

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Morrison / Wells

Lesson 24

Morrison / Wells CLB: A Comp Guide to IC3 3E

Objectives

O Describe a network.O Explain the benefits of a network.O Identify the risks of network computing.

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Vocabulary

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O biometric security measures

O cable modemO client

O client/server network

O communication channels

O digital subscriber line (DSL)

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VocabularyO Describe the roles of clients and

servers on a network.O List and describe the types of

networks.O List and describe communications

media and hardware.O Describe network security.

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Vocabulary

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O extranetO firewallO hackerO hub

O InternetO intranetO local area

network (LAN)O modem

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Vocabulary (continued)

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O nodeO peer-to-peer

networkO proxy server

O Public Switched Telephone Network (PSTN)

O routerO server

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IntroductionO Connecting computers through a

network, a group of two or more computers linked together, allows users to share software applications and to share hardware devices such as printers, scanners, and other hardware add-ons.

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Introduction

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O server operating system

O T-1 lineO wide area

network (WAN)

O WiMAX -Worldwide Interoperability for Microwave Access

O wireless Internet service provider

O (WISP)-wirelessISP

O wireless LAN (WLAN)

Lesson 24


Use of networksO Companies and organizations use

networks to connect employees and subsidiaries nationally and even internationally.

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Introducing Networks

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O The Public Switched Telephone Network (PSTN) supports telephone service and is the world’s collection of interconnected commercial and government-owned voice-oriented systems.

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Network BenefitsO The biggest network of all is the

Internet. Network benefits include:O Information sharingO Collaborative environmentO Hardware sharingO Software sharingO Enhanced communications

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Information sharing

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Client/Server NetworksO The term client/server network

describes a software architectural model relationship.

O In most instances, the client is a software program such as Internet Explorer. The server is hardware and can be one of many types of servers, such as a mail server, a database server, an FTP server, an application server, or a Web server.

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Risks of Networked Computing

O As with any technology, disadvantages also exist. Disadvantages of networks include:O Individual loss of autonomyO Malicious codeO Network faultsO Setup and management costsO E-mail is not necessarily private

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Network OsO Server operating systems are high-

end programs designed to provide network control and include special functions for connecting computers and other devices into a network.

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Network TypesO Networks are divided into two main

types: local area networks (LANs) and wide area networks (WANs).

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Network Types (continued)

O Wide Area Networks:O A WAN covers a large geographical area and

can contain communication links across metropolitan, regional, or national boundaries.

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Network Types (continued)

O Local Area Networks:

O Most LANs connect personal computers, workstations, and other devices such as printers and scanners in a limited geographical area.

17Wireless LAN

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Network types include:

O Client/server network: Server manages resources

O Peer-to-peer network: All computers are equal

O Intranet: Used within an organizationO Extranet: Specific outside users can

accessO Internet: Global network allows

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Communication Hardware:

O Communication hardware devices facilitate the transmitting and receiving of data. Examples are:O Modem: Converts analog signals to digital and

vice versaO Cable modem: Uses coaxial cableO Digital subscriber line: Uses ordinary phone linesO T-1: Type of fiber-optic telephone lineO Wireless: Delivers fast connection speeds

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Network Security Issues

O Passwords are the most common form of restricting access to data.

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Establishing and maintaining computer security is necessary to keep hardware, software, and data safe from harm or destruction.

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Network Security Issues (continued)

O Other security measures include:O Electronic identification cardsO Firewalls to protect companies’ networks from external networksO Antivirus softwareO A proxy server that acts as an intermediary between a user and

the Internet.

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Network Security Issues (continued)

O Planning for Security:O Companies must plan for security before it is

neededO Institute a selective hiring process.O Regularly back up data and store it off site.O Employ biometric security measures.

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Network Security

O Wireless networking is very common, but has many security issues and hackers have found it very easy to access wireless networks.

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SummaryIn this lesson, you learned:O A network is a group of two or

more computers linked together.

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SummaryO A telephone network is similar in

makeup to a computer network. The Public Switched Telephone Network (PSTN) supports telephone service, and it is the world’s largest collection of interconnected commercial and government-owned voice-oriented systems.

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Summary (continued)O You can use a network for

information sharing, hardware sharing, software sharing, and as a collaborative environment.

O Networks are divided into two main types: local area networks and wide area networks.

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summaryO Local area networks (LANs) connect

personal computers, workstations, and other devices such as printers and scanners in a limited geographical area, such as an office building, a school, or a home.

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Summary (continued)

O A wide area network (WAN) is made up of several connected local area networks.

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SummaryO In a client/server network, one or

more computers on the network act as a server. The server manages network resources. In a peer-to-peer network, all of the computers are equal.

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Summary (continued)O Data security is a risk with many

networks. Some risks to computers are natural causes, some are accidents, and others are intentional.

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SummaryO The best way to protect data is to

effectively control the access to it. Generally, this protection is the responsibility of the network administrators and security personnel.

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SummaryO If unauthorized persons gain access

to data, they may obtain valuable information or trade secrets. Hackers are people who break into computer systems to steal services and information.

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Summary (continued)O Transmission media can be either

physical or wireless.O A modem is a type of communication

device. A hub is a device that controls the incoming and forwarding of data. A router directs traffic on the Internet or on multiple connected networks.

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SummaryO No computer is designated as the

server. People on the network each determine what files on their computer they share with others on the network.

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Computer Networks Fundamentals

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