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Week 5: Making the Most of Internet Resources

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The Origin of the Internet• ARPANET:

– Advanced Research Projects Agency Network– Funded by the U.S. government in the 1960s– Allowed computers at leading universities and research organizations

to communicate with each other over great distances

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The Web

• The Web is a part of the Internet distinguished by:– common communication protocols TCP/IP and HTML

– special links (called hyperlinks)

• Web invented in 1989 by Tim Berners-Lee

• 1993, National Center for Supercomputing Applications releases the Mosaic browser

• Developers of Mosaic release Netscape (1994)

• Netscape is beginning of Web’s major growth

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The Internet vs. The Web

• Internet – part of the system that is primarily hardware infrastructure (telecommunications, routers, servers, disk drives, etcetera)

• Web – part of the system that contains intellectual property in many multimedia formats (test files, graphic files, sound files, video files, etc.)

INTERNET

WWW

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Internet Communications

• Instant Messaging

• Voice over Internet (VoIP)

• Weblogs

• Podcasts

• Webcasts and Wikis

• Chat Rooms

• Newsgroups

• E-mail

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Instant Messaging

• Real-time text-based conversations

• Set up a list of contacts– Buddy list

• Contacts must be online

• IM software detects presence

• Example: AOL Instant Messenger

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Voice over Internet Protocol• VoIP - The Internet as a means to place phone calls• Uses technology similar to e-mail to send voice data digitally • Requires

– a microphone

– an Internet connection– A VoIP provider

• Services differ– Free services require an account on both ends

– Paid services connect phone to computer– Cable and DSL providers offer phone through broadband– WiFi IP phones call through Internet hotspots and wireless networks

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Weblogs (blogs)• Known as blogs

• Available to the public

• Simple to create, read, and manage

• Entries listed on a single page

• Most recent entry at the top

SearchableSome are personalMany are focused on a topic

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Podcasts

• Video blog (vlog) – entries are video clips• Podcasts – compressed audio/video files

distributed on the Internet• RSS (Really Simple Syndication) technology

allows constant updates for subscribers• Podcasts are all over the Web

– Requires “aggregator” software to gather podcasts– Requires media player software to play them

• Simple to create and attach RSS files DEMO

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Webcasts and Wikis

• Webcasts broadcast audio/visual files but are not updated– use streaming media

• A wiki is a Web site that allows anyone to change its content

• Wikis provide an excellent source for collaborative writing

• Unlike blogs, wikis can be edited for a “common” opinion

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E-mail

• Electronic mail• Primary means

of communication

• E-mail accounts– Client-based

– Web-based

• Spam – Prevention

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Chat Rooms• Real-time text-based conversations• Rooms focus on specific topics or interests• Identity protection

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Newsgroups

• Online discussion forums• Post and reply to messages

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Social Networking

• Social networking sites like Facebook.com• Members share common interests• Members communicate by voice, chat,

instant message, video, and blogs • Members create personalized profiles • Growth has been explosive • Risks must be recognized and reduced

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Web Entertainment

• Multimedia:– Involves forms of media and

text• Graphics• Audio• Video

– Streaming audio and video– Plug-in

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Web 2.0

– Shorthand for the new use-centred Internet where people publicly modifies other’s work, whether it’s an encyclopedia entry or a photo album.

– More on this soon.

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Conducting Business Over the Internet

• E-Commerce:– Electronic commerce– Business-to-consumer (B2C)– Business-to-business (B2B)– Consumer-to-consumer (C2C)– Secure transactions

Manufacturer

Suppliers

Retailer

B2BE-commerce

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Online Annoyances

• Spam – electronic junk mail• Pop-ups – intrusive advertising• Cookies – tracking user’s browsing habits• Spyware – programs that collect data from a

user’s computer• Malware - software that has a malicious intent • Phishing and Hoaxes – Ruses to fool and maybe

steal from users

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Spam

• Junk e-Mail• Spam filters• Antispam

practices

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Pop-ups

• Usually advertising

• Pop-up automatically

• Pop-up blockers

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Cookies

• Text files stored on client computers when visiting Web sites

• Used on return visits to Web sites

• Unique ID number• Personal information

remembered• Privacy risk

– Selling information

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Spyware• Added as a program

piggybacked with a requested program

• Gathers information, usually about surfing habits

• Antivirus software doesn’t detect it

• Spyware removal programs are required

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Malware

• Software that has a malicious intent • Spyware is a form of malware• Other forms are viruses, worms, and Trojan

horses• Designed to render a computer useless or

penetrate it completely

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Phishing and Hoaxes

• Phishing is a phony communication• Attempts to scam someone into sending vital

information• Hoaxes are attempts to scam people into sending

money, or join a chain letter

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Navigating the Web: Web Browsers

• Computer software• Graphical• Enables Web navigation• Popular browsers:

– Foxfire Mozilla– Internet Explorer– Netscape Navigator– Safari (Mac OSX)

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Browser Toolbars

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Web Sites• Web site:

– Collection of related Web pages– First page known as Home or Index page

• Web page:– HTML document

• Text and graphics

– Unique address– Hyperlinks

Home page

Related pages

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URL• URL:

–Uniform Resource Locator–Unique Web page address

URL http://

Protocol identifies the means of access

www.nytimes.com/

Domain name contains the host and top-level domain

Pages/cartoons/

Path identifies the subdirectories

within the Web site

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Current Top-Level Domains

.aero Members of the air transport industry.biz Businesses

.com Can be used by anyone.net Networking organizations

.edu Degree granting institutions.gov United States government

.mil United States military.ca Canada

.tv Tuvalu (funny story).org Organizations (often nonprofits)

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Evaluating Web Sites

• Who is the author of the article or Web site sponsor?

• What audience is the site geared toward?• Is the site biased?• Is the information current?• Are links available?

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Future of the Internet

• Large Scale Networking (LSN):– Research and development

of cutting-edge networking and wireless technologies

• Web 2:– Project sponsored by

universities, government, and industry to develop new Internet technologies

– Internet2 backbone supports transmission speeds of 9.6 Gbps

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The Following SlidesAre Optional

For Your Informational Pleasure

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Client and Server

• Client computer:– Users connect to the Internet– Request data and Web pages

• Server computers:– Store Web pages and data

– Return the requested data to the client Server

Client

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Search Engines

• User keys word or phrase in search box

• “Spider” or “Web Crawler” program scans Web pages

• Results are indexed and sent to the client

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Connecting to the Internet• Dial-up connection:

– Uses standard telephone line

– Least costly connection

– Requires a modem

• Converts analog and digital signals

– Slowest connection speed (56Kbps)

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Broadband Connections

• Digital Subscriber Lines– Faster than dial-up

• Upload (300Kbps – 1.5Mbps)• Download (1Mbps – 1.5Mbps)

– Requires special DSL modem

DSL modem

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Broadband Connections

• Cable:– Uses TV coaxial cable– Fast connection speed

(500Kbps – 4Mbps)– Speed depends on number

of users– Not available in all areas

– Requires a cable modemCoaxial cable

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Satellite Connections

• Uses a satellite dish and coaxial cable– Download speed 500

kbps

– Upload speed 100 kbps

– Signal is affected by location and weather

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Comparing Internet Connection Options

Connection Option

Maximum Upload Data Transfer Rate (approximate)

Maximum Download Data Transfer Rate (approximate)

Dial-Up 56 Kbps 56 Kbps

DSL (ADSL)

300 Kbps 1 Mbps

DSL (SDSL)

1.5 Mbps 1.5 Mbps

Cable 500 Kbps 4 Mbps

Satellite 100 Kbps 500 Kbps

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Choosing an ISP

• Factors to consider:– Customer service

– Local access numbers– E-mail options

– Cost

– Trial period

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Internet Service Providers• ISP:

– Internet service provider– Provide user access to the

Internet– National, regional, or local

companies

• OSP:– Online service provider

– Provide online proprietary content as well as Internet access

– AOL, CompuServe, MSN