1. 1 Lesson 24 Network Fundamentals Computer Literacy BASICS: A Comprehensive Guide to IC 3, 3 rd Edition Morrison / Wells

2. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 222 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.

3. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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 333

4. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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) 444

5. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 555

6. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 666

7. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E Network Benefits The biggest network of all is the Internet. Network benefits include: – Information sharing – Collaborative environment – Hardware sharing – Software sharing – Enhanced communications 777 Information sharing

8. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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 888

9. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 999

10. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E Network Types Networks are divided into two main types: local area networks (LANs) and wide area networks (WANs). 10

11. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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) 11 Wireless LAN

12. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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 12

13. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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 13

14. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E Network Security Issues Passwords are the most common form of restricting access to data. 14 Establishing and maintaining computer security is necessary to keep hardware, software, and data safe from harm or destruction.

15. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 15

16. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 16

17. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 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. 17

18. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 18 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. 18

19. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 19 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. 19

20. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 20 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. 20

21. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 21 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. 21

22. Lesson 24 Morrison / WellsCLB: A Comp Guide to IC 3 3E 22 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. 22