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Computer Networks Fundamentals. Morrison / Wells. Objectives. Describe a network. Explain the benefits of a network. Identify the risks of network computing. 2. 2. Vocabulary. biometric security measures cable modem client. client/server network communication channels
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Computer Networks Fundamentals Morrison / Wells
Objectives • Describe a network. • Explain the benefits of a network. • Identify the risks of network computing. 2 2
Vocabulary • biometric security measures • cable modem • client • client/server network • communication channels • digital subscriber line (DSL) 3 3
Vocabulary • 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.
Vocabulary • extranet • firewall • hacker • hub • Internet • intranet • local area network (LAN) • modem
Vocabulary (continued) • node • peer-to-peer network • proxy server • Public Switched Telephone Network (PSTN) • router • server 6 6
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. 7 7
Introduction • server operating system • T-1 line • wide area network (WAN) • WiMAX-Worldwide Interoperability for Microwave Access • wireless Internet service provider • (WISP)-wirelessISP • wireless LAN (WLAN)
Use of networks • Companies and organizations use networks to connect employees and subsidiaries nationally and even internationally.
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. 10 10
Network Benefits • The biggest network of all is the Internet. Network benefits include: • Information sharing • Collaborative environment • Hardware sharing • Software sharing • Enhanced communications Information sharing 11 11
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. 12 12
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 13 13
Network Os • 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.
Network Types • Networks are divided into two main types: local area networks (LANs) and wide area networks (WANs). 15 15
Network Types (continued) • Wide Area Networks: • A WAN covers a large geographical area and can contain communication links across metropolitan, regional, or national boundaries. 16 16
Network Types (continued) • Local Area Networks: • Most LANs connect personal computers, workstations, and other devices such as printers and scanners in a limited geographical area. Wireless LAN 17
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
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 19 19
Network Security Issues • Passwords are the most common form of restricting access to data. • Establishing and maintaining computer security is necessary to keep hardware, software, and data safe from harm or destruction. 20 20
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. 21 21
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. 22 22
Network Security • Wireless networking is very common, but has many security issues and hackers have found it very easy to access wireless networks. 23 23
Summary In this lesson, you learned: • A network is a group of two or more computers linked together. 24 24
Summary • 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.
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. 26 26
summary • 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.
Summary (continued) • A wide area network (WAN) is made up of several connected local area networks. 28 28
Summary • 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.
Summary (continued) • Data security is a risk with many networks. Some risks to computers are natural causes, some are accidents, and others are intentional. 30 30
Summary • 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.
Summary • 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.
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. 33 33
Summary • 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.