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Lesson 24Network Fundamentals
Computer Literacy BASICS: A Comprehensive Guide to IC3, 3rd Edition
Morrison / Wells
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Objectives
Describe a network. Explain the benefits of a network. Identify the risks of network computing. Describe the roles of clients and servers on a network. List and describe the types of networks. List and describe communications media and
hardware. Describe network security.
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Vocabulary
biometric security measures
cable modem client client/server network communication
channels digital subscriber line
(DSL)
extranet firewall hacker hub Internet intranet local area network (LAN) modem
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Vocabulary (continued)
node peer-to-peer network proxy server Public Switched
Telephone Network (PSTN)
router server
server operating system T-1 line wide area network (WAN) WiMAX wireless Internet service
provider (WISP) wireless LAN (WLAN)
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Introduction
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.
Companies and organizations use networks to connect employees and subsidiaries nationally and even internationally.
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Introducing Networks
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 Benefits
The biggest network of all is the Internet. Network benefits include:– Information sharing– Collaborative environment– Hardware sharing– Software sharing– Enhanced communications
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Information sharing
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Risks of Networked Computing
As with any technology, disadvantages also exist. Disadvantages of networks include:– Individual loss of autonomy– Malicious code– Network faults– Setup and management costs– E-mail is not necessarily private
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Client/Server Networks
The term client/server network describes a software architectural model relationship.
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.
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 Types
Networks are divided into two main types: local area networks (LANs) and wide area networks (WANs).
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Local Area Networks: Most LANs connect
personal computers, workstations, and other devices such as printers and scanners in a limited geographical area.
Network Types (continued)
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Wireless LAN
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Network Types (continued)
Wide Area Networks: A WAN covers a large geographical area and can contain
communication links across metropolitan, regional, or national boundaries.
Network types include:– Client/server network: Server manages resources– Peer-to-peer network: All computers are equal– Intranet: Used within an organization– Extranet: Specific outside users can access– Internet: Global network allows worldwide connection
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Network Communications
Communication Hardware: Communication hardware devices facilitate the
transmitting and receiving of data. Examples are:– Modem: Converts analog signals to digital and vice
versa– Cable modem: Uses coaxial cable– Digital subscriber line: Uses ordinary phone lines– T-1: Type of fiber-optic telephone line– Wireless: Delivers fast connection speeds
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Network Security Issues
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)
Other security measures include:– Electronic identification cards– Firewalls to protect companies’ networks from
external networks– Antivirus software– A proxy server that acts as an intermediary
between a user and the Internet.
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Network Security Issues (continued)
Planning for Security: Companies must plan for security before it is
needed– Institute a selective hiring process.– Regularly back up data and store it off site.– Employ biometric security measures.
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Network Security Issues (continued)
Wireless Security: 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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Summary
In this lesson, you learned: A network is a group of two or more computers
linked together. 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)
You can use a network for information sharing, hardware sharing, software sharing, and as a collaborative environment.
Networks are divided into two main types: local area networks and wide area networks.
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)
A wide area network (WAN) is made up of several connected local area networks.
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. 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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Summary (continued)
Data security is a risk with many networks. Some risks to computers are natural causes, some are accidents, and others are intentional.
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. 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)
Transmission media can be either physical or wireless.
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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