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CHAPTER 4Telecommunications

and Networking

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1. What Is a Computer Network?2. Network Fundamentals3. The Internet and the World Wide

Web4. Network Applications

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>>>1. Compare and contrast the major types of

networks.

2. Describe the wireline communications media and transmission technologies.

3. Describe the most common methods for accessing the Internet.

4. Explain the impact that networks have had on business and everyday life for each of the six major categories of network applications.

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OPENING >• Get Rid of E-Mail?

Seriously?

Is it feasible for your university to eliminate e-mail? Why or why not? Would you support such a policy at your school? Why or why not?

Describe the advantages and disadvantages of eliminating e-mail from an organization. Provide specific examples to support your answers.

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What Is a Computer Network?

4.1

• Computer Network• Bandwidth

Broadband

• Local Area Networks (LAN)• Wide Area Networks (WAN)

Metropolitan area networks (MAN)

• Enterprise Networks

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Basic Concepts

• Computer networks:ConnectTransmitShare work

• Bandwidth: transmission capacityBps, Kbps, Mbps

• LAN: limited geo area

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Figure 4.1: Ethernet Local Area Network (LAN)

One thing missing

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Figure 4.2: Enterprise Network

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Network components

• Clients• Server

Network operating systems (NOS)

• Media• Communications processors

SwitchRouter

• Protocol

• Logical “flow” of the above

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Network Fundamentals

4.2

• Analog and Digital Signals• Modem• Communications Media and

Channels• Network Protocols• Types of Network Processing

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Figure 4.3: Analog and Digital Signals

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Modem

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Communications Media and Channels

• Twisted-Pair Wire• Coaxial Cable• Fiber Optics

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Communications Media: Twisted-Pair Wire

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Communications Media: Coaxial Cable

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Communications Media: Fiber Optics

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Table 4.1: Advantages and Disadvantages of Wireline Communications Channels

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Network Protocols

• A common set of rules and proceduresDefines _____ (things)Specifies _________ (ways)Handles _______________ (situations)Facilitates and assures _________ (obj)

• Ethernet• Transmission Control Protocol /

Internet Protocol (TCP/IP)

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Transmission Control Protocol / Internet Protocol

• Three Basic Functions of TCP• Packets & Packet Switching• Four Layers of the TCP/IP Reference

Model

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Figure 4.8: Packet Switching

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Three Basic Functions of the TCP

1. Manages the movement of data packets between computers by establishing a connection between the computers

2. Sequences the transfer of packets3. Acknowledges the packets that have

been transmitted

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Four Layers of the TCP/IP Reference Model

1. Application Layer2. Transport Layer3. Internet Layer4. Network Interface Layer

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Figure 4.7: The Four Layers of TCP/IP Reference Model

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Types of Network Processing

• Distributed Processing• Client/Server Computing• Peer-to-Peer Processing

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’S ABOUT BUSINESS 4.1

• Internet Access in Cuba

Describe the advantages and disadvantages of the global Internet to Cuban citizens.

Describe the advantages and disadvantages of the global Internet to the Cuban government.

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The Internet and the World Wide Web

4.3

• Internet versus WWW• Accessing the Internet• The Future of the Internet• The World Wide Web

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Figure 4.9: Internet (backbone in white)

40 maps that explain the internet

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The World Wide Web (WWW)

• World Wide Web• Internet• Intranet• Extranet

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Accessing the Internet

• Connecting via an Online ServiceISP; NAP

• Connecting via Other MeansInternet kiosksSmart phones and iPadsCybercafes

• Addresses on the Internet

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Table 4.2: Internet Connection Methods

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Future of the Internet

Experts are concerned that Internet users will experience brownouts from 3 factors:1. increasing number of people working

online2. Popularity of Web sites such as YouTube

requiring large amounts of bandwidth3. Demand for high-definition television

delivered over the Internet

Domain name system (DNS)(AKA: Domain name service)

Some country domains that are commonly seen: .au, .ca, .cn, .fr, .hk, .jp, .kr, .mx, .ru, .sg, .tv(!), .tw, .ua, .uk,

Domain name system (DNS) – Converts IP addresses into domains: www.csun.edu = 130.166.238.195

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Network Applications4.4

• Discovery• Communication• Collaboration • E-learning and Distance

EducationVirtual Universities

• Telecommuniting

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Network Applications: Discovery

• Search Engines and Metasearch Engines

• Publication of Material in Foreign Languages

• Portals

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Publication of Materials in Foreign Languages

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’S ABOUT BUSINESS 4.2

• Just Exactly What Is Quara? Is Quora a search engine, a knowledge-

management system, or both? Provide specific examples to support your answer.

Is there an inherent problem with Quora itself selecting experts to whom the site sends questions? Support your answer.

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Network Applications: Portals

• Commercial portal• Affinity portal• Corporate portal• Industrywide portal

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Affinity Portals

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Network Applications: Communication

• Electronic Mail• Web-Based Call Centers• Electronic Chat Rooms• Voice Communication

Voice Over Internet Protocol (VoIP)

• Unified Communications• Collaboration• Electronic Teleconferencing

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Telecommunication: Teleconferencing/Telepresence

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Network Applications: Collaboration (PP. 122-125)

• Workgroup• Workflow• Virtual Team• Virtual Collaboration• Crowdsourcing• Synchronous versus Asynchronous• Collaboration Tools

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Collaboration Tools

• Microsoft Sharepoint• Google Drive• IBM Lotus Quikr• Jive

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Network Applications: E-Learning versus Distance Education

• E-Learning• Distance Education

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Virtual Universities

• University of Phoenix• California Virtual Campus• University of Maryland

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Network Applications:

Telecommuting

• Knowledge workers• Digital Nomads