CHAPTER 6 Networks

Chapter Outline 6.1 What Is a Computer Network? 6.2 Network Fundamentals 6.3 The Internet and the World Wide Web 6.4 Network Applications

Learning Objectives 1. Define the term computer network, and compare and contrast the two major types of networks. 2. Describe the differences among the three types of wireline communications media, and discuss the main advantages and disadvantages of each type. 3. Differentiate between the Internet and the World Wide Web, and describe the most common methods for accessing the Internet.

Learning Objectives (continued) 4. Identify six major categories of network applications, provide an example of each, and explain how that application supports business functions.

6.1 What Is a Computer Network? In a computer network, connected computers: Work together Are interdependent Exchange data with each other © Ilin Sergey/Age Fotostock America, Inc.

Broadband Fiber opticsCoaxial cable Source: Philip Hatson/Photo Researchers, IncSource: GIPhotoStock/Photo Researchers, Inc

Size of Computer Networks Home computer network National computer network Global computer network

Local Area Networks

Wide Area Networks © Ilin Sergey/Age Fotostock America, Inc.

Enterprise Network

6.2 Network Fundamentals Analog and Digital Signals Communications Media and Channels Transmission Technologies Network Protocols Types of Network Processing

Analog and Digital Signals

Communications Media and Channels Twisted-pair wire Coaxial cable Fiber optics Sources: deepspacedave/Shutterst ock, GIPhotoStock/Photo Researchers, Inc, Philip Hatson/Photo Researchers

Transmission Technologies Digital subscriber line (DSL) Asynchronous transfer mode (ATM) Synchronous optical network (SONET) T-carrier system

Network Protocols Ethernet Transmission Control Protocol/Internet Protocol (TCP/IP)

The Four Layers of the TCP/IP Protocol

Packet Switching

Types of Network Processing Client/server computing Peer-to-peer processing © Matthias Pahl/Age Fotostock America, Inc. © Toh Kheng Ho/Age Fotostock America, Inc.

6.3 The Internet and the World Wide Web Accessing the Internet The Future of the Internet The World Wide Web Image of the Internet in the United States Source: © Mark Stay/iStockphoto)

An Intranet © Corbis/Age Fotostock America, Inc.

Accessing the Internet Connecting via an online service Internet kiosks Dial-up DSL

Accessing the Internet Cable Modem Satellite Wireless Fiber to the Home

Addresses on the Internet IP v 4 32 bits128 bits IP v 6

Addresses on the Internet Domain names Top-level domain Name of the organization Name of the specific computer

Internet Address example Top level domain: edu Name of the organization: Auburn University Name of the specific computer: business

The Future of the Internet Source: © Mark Stay/iStockphoto)

The World Wide Web Not the same thing as the Internet Home page Uniform resource locator © Ilin Sergey/Age Fotostock America, Inc.

Browser Competition © Matthias Pahl/Age Fotostock America, Inc.

6.4 Network Applications Discovery Communication Collaboration E-Learning and Distance Learning Virtual Universities Telecommuting

Discovery Search engines Metasearch engines Discovery of material in foreign languages Portals

Four Large Search Engines The largest search engines are: Google Yahoo Bing Baidu © Claver Carroll/Age Fotostock America, Inc.

Metasearch Engines Figure 4.10 The KartOO home page (

Publication of Material in Foreign Languages

Portals Commercial (public) portals Affinity portals Mobile portals Corporate portals Industry wide portals

Affinity Portal (example) Figure 4.12 University of West Georgia affinity portal. (Courtesy of West Georgia University.)

Industrywide Portal (example) Figure 4.13 The TruckNet portal

Communication Electronic mail ( ) Web-based call centers (customer call center) Electronic chat room Voice Unified © Mario S Ragma Jr/Age Fotostock America, Inc.

Electronic Mail Source: Stockphoto4u/iStockphoto

Call Centers © Dinodia/Age Fotostock America, Inc.

Voice Communication Two examples of Internet telephony (VoIP) Skype Vonage

Collaboration Work group Virtual group (team) Source: Howard Kingsnorth/The Image Bank/Getty Images, Inc.

Collaboration (continued) Virtual collaboration Collaboration software Electronic Teleconferencing E-Learning and Distance Learning

Crowdsourcing © YURI ACURS/Age Fotostock America, Inc.

Software products supporting collaboration Microsoft Sharepoint IBM Lotus Quickr Google Docs Jive Software

Telepresence Systems See video on Cisco Magicvideo Source: PRNews Foto/Polycom, Inc./NewsCom

E-Learning and Distance Learning E-Learning Distance learning Source: Mike Flippo/Shutterstock

Benefits of E-Learning Self-paced learning increases content retention. Online materials deliver high-quality, current content. Students have the flexibility of learning from any place at any time at their own pace. Learning time generally is shorter, and more people can be trained due to faster training time. Training costs can be reduced.

Drawbacks of E-Learning Instructors may need training to be able to teach electronically. The purchase of additional multimedia equipment may be necessary. Students must be computer literate and may miss the face-to-face interaction with instructors. There are issues with assessing students’ work, as instructors really do not know who completed assignments.

Telecommuting Source: © Maria R.T. Deseo/PhotoEdit

Telecommuting Benefits For Employees Reduced stress, improved family life Employment opportunities for single parents and persons with disabilities For Employers Increased productivity Ability to retain skilled employees

Telecommuting Disadvantages For Employees Feelings of isolation No workplace visibility Potential for slower promotions For Employers Difficulties in supervising work Potential information security problems Additional training costs

Chapter Closing Case The Problem The Solution The Results