CHAPTER 6Networks

6.1 What Is a Computer Network?

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Local Area Networks

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

Analog and Digital Signals

Communications Media and Channels

Twisted-pair wire

Coaxial cable

Fiber optics

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Network ProtocolsA protocol is the set of rules and procedures governing transmission across a network.

Ethernet is a common LAN protocol.

Transmission Control Protocol/Internet Protocol (TCP/IP) is a file transfer protocol that can send large files of information across sometimes unreliable networks with assurance that the data will arrive uncorrupted

The Four Layers of the TCP/IP Protocol

Packet Switching

Types of Network Processing

Client/server computing

Peer-to-peer processing•The first type of peer-to-peer (P2P) processing accesses unused CPU power among networked computers.•The second type of P2P is real-time, person-to-person collaboration.•The third type of P2P is open-source, free, peer-to-peer file-sharing.

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Accessing the InternetCable Modem

Satellite

Wireless

Fiber to the Home

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Addresses on the Internet

IPv432 bits 128 bits

IPv6

Addresses on the InternetDomain names consist of multiple parts, separated by dots, which are read from right to left.

▫ Top-level domain the rightmost part of an Internet name; common top-level domains are .com, .edu, .gov

▫ Name of the organization the next section of the Internet name

▫ Name of the specific computer the next section of the Internet name

Internet Address examplewww.business.auburn.edu

Top level domain: edu

Name of the organization: Auburn University

Name of the specific computer: business

The World Wide Web

•World wide web: A system of universally accepted standards for storing, retrieving, formatting, and displaying information via a client/server architecture.

• Not the same thing as the Internet• Home page a text and graphical screen display that

usually welcomes the user and explains the organization that has established the page.

• Uniform resource locator the set of letters that points to the address of a specific resource on the Web.

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6.4 Network Applications Discovery Communication Collaboration E-Learning Telecommuting

Discovery

▫Broswer Competitioin▫Search engines▫Metasearch engines▫Discovery of material in foreign languages▫Portals

Portals - is a Web-based, personalized gateway to information and knowledge that provides relevant information from different IT systems and the Internet using advanced search and indexing techniques.

• Commercial (public) portals- offer content for diverse communities and are most popular portals on the Internet.

• Affinity portals support communities such as a hobby group or a political party.

• Mobile portals are accessible from mobile devices

• Corporate portals offer a personalized single point of access through a Web browser

• Industry wide portals for entire industries.

CommunicationElectronic mail (e-mail)Web-based call centers (customer call center)Electronic chat roomVoice (VOIP, SKYPE)Unified (integrates voice, fax, chat, location, etc.)

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Collaboration Work group refers specifically to two or more

individuals who act together to perform some task.

Virtual group (team) is when group members are in different locations.

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Collaboration (continued)

• Virtual collaboration is the use of digital technologies that enable organizations or individuals to collaboratively plan, design, develop, manage and research products, services and innovative applications.

• Workflow technologies facilitate the movement of information as it flows through the sequence of steps that make up an organization’s work procedures. Includes workflow management and workflow systems

• Groupware refers to software products that support groups of people who share a common task or goal and who collaborate to accomplish it.

• Electronic Tele/Videoconferencing• E-Learning and Distance Learning

Crowdsourcing refers to outsourcing a task to an undefined, generally large group of peoplein the form of an open call.

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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

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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