Origin of the Internet

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LECTURE 1
Using the Internet: Making the Most of the Web’s Resources
The Origin of the Internet


ARPANET:


Advanced Research Projects Agency Network



Funded by the US Government in the 1960s



Allowed computers at leading universities and research
organizations to communicate with each other over great distances



The Internet was created to respond to two concerns: to establish a safe
form of military communications and to create a means by which all
computers could communicate.



Scientists were asked to come up with a solution to secure
communications between large computer centers in case of a nuclear
attack. They responded by inventing packet-switching and routers. By
taking data messages and breaking them into small packets, each packet
could be addressed and sent individually to a destination through a series
of routers. The routers, like robot traffic cops, would send each packet
along the optimum path to the next router, depending on traffic and
availability.



This development also gave birth to a network that could be scaled up
infinitely. It could be argued that the scientists who quietly built the first
packet-switched network in 1969 were more important to the future than
the NASA scientists who landed a man on the moon in the same year.

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,
etcetera): the means to access the Internet.



Internet development in the early 1990s gave birth to the Web. One
crucial development was the introduction of Hypertext Markup Language
(HTML) and Hypertext Transfer Protocol (HTTP): the software technologies
that allow Web pages to link to other Web pages, whether they are on the
same server or on the other side of the world.



HTTP (Hypertest Transfer Protocol) is the code in a web address URL that specifies
that you are looking for a common web site. Basically this protocol establishes the
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standard that computers on the Internet use to communicate and transfer data
through web browsers. Other protocols you might see instead of HTTP are things like
FTP, GOPHER and HTTPS. HTML (Hypertext Markup Language) is the
programming language that web pages are created in. When you publish a website
to a host, this is the core language that the website is coded in.


The other critical development was the browser, multi-platform software
that allows users to see HTML files, called Web pages.



Thus, the Web is a subset of the Internet, but because of its tremendous
use, it represents the largest amount of Internet traffic.

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

The Internet is a huge client/server network. Thus, a computer connected
to the Internet acts in one of two ways: it is either a client, a computer
that asks for data, or a server, a computer that receives the request and
returns the data to the client.

Connecting to the Internet


Dial-up connections:


Uses standard telephone line



Least costly connection



Requires a modem






Modulate: converts digital signals the computer can
understand to analog signals that can travel over the phone
line.



Demodulate

Slowest connection speed (56kbps)

To take advantage of the resources the Internet offers, you need a means
to connect your computer to it. Home users have several connection
options available. The most common is a dial-up connection.

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A dial-up connection is the least costly method of connecting to the
Internet, needing only a standard phone line and a modem. A modem is a
device that converts (modulates) the digital signals the computer
understands to the analog signals that can travel over phone lines. In turn,
the computer on the other end must also have a modem to translate
(demodulate) the received analog signal back to a digital signal for the
receiving computer to understand.



Modern desktop computers generally come with internal modems. Laptops
use either internal modems or PC cards that are inserted into a special slot
on the laptop.



Current modems have a maximum data transfer rate of 56 Kbps, usually
referred to as 56K

Broadband Connections


Digital Subscriber Lines




Faster than dial-up


Upstream (16Kbps -640kbps)



Downstream (1.5 Mbps – 9 Mbps)



ADSL: asymmetrical DSL



SDSL: same upload and download speed.

Requires special DSL modem



Other connection options, called broadband connections, offer faster
means to connect to the Internet. Broadband connections include DSL,
cable, and satellite.



DSL uses a standard phone line to connect to the Internet. However, the
line is split between digital and voice, meaning that the digital signal does
not have to be converted into sounds, and greater speeds can be realized.



DSL requires a special DSL modem.



Although the monthly fee is higher than dial-up, there is no need for a
second phone line, and often the end price is comparable, but the Internet
speed is at least double.



Not all areas of the U.S. have DSL. Also, in order to use DSL, your
telephone connection must be within fairly close proximity of a switching
station. DSL provider Web sites include interactive tools you can use to
determine whether your phone line is capable of including a DSL
connection.

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The more typical DSL transmissions download data from the Internet
faster than they can upload data. Such transmissions are referred to as
Asymmetrical Digital Subscriber Line (ADSL). Other DSL
transmissions, called Symmetrical Digital Subscriber Line (SDSL),
upload and download data at the same speed.

Broadband Connections


Cable:


Uses TV coaxial cable



Fast connection speed (300kbps – 4mbps)



Speed depends on number of users



Not available in all areas



Requires a cable modem



Another broadband connection is cable Internet.



Cable Internet uses coaxial cable and a cable modem.



If your cable company has an Internet service, you can receive data at
speeds up to 4 Mbps and send data at approximately 500 Kbps. As
technology improves, these transfer rates also will improve.



This always-on connection can be slowed by the number of users
connected at any one time, and it is not available in all areas.

Satellite Connections


Uses a satellite dish and coaxial cable


Download speed 500kbps



Upload speed 100kbps



Signal is affected by location and weather



Satellite Internet is another broadband option.



You need a satellite dish, which is placed outside your home and connects
to your computer with coaxial cable. Therefore, the initial equipment
investment is high.



Most satellite connections are used by people in rural areas unable to get
cable or DSL connections.



Even though bandwidth can be high, the signal must travel a long distance
from the satellite and back, increasing the delay time.

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In North America the southern sky has to be free of obstruction, and heavy
rain can cause interference in the signal.

Comparing Internet Connection Options
Connection Option

Maximum Upload Data Transfer
Rate (approximate)

Maximum Download Data Transfer Rate

Dial-Up

56kbps

56kbps

DSL (ADSL)

300 kbps

1 Mbps

DSL (SDSL)

1.5mbps

1.5mbps

Cable

500 kbps

6 mbps

Satellite

100kbps

400kbps

(approximate)

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

The differences between Internet Service Providers and Online Service
Providers has to do with content that is exclusively available to the OSP
clients. Firms like America Online offer web access but when users log on
they must enter through AOL’s site. There they receive information and
services unavailable to non-subscribers. Whether these services are worth
the premium price is a question each consumer must answer. Generally
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connection speed is similar and with the enormous amount of information
available on the web, many have left the OSP providers in order to save
money.

Choosing an ISP




Factors to consider:


Customer service



Local access numbers



E-mail options



Cost



Trial period

The choice of Internet Service Provider should be based on cost verse
service. It is very important that a dial-up provider offer a local access
number, so that there are no long distance charges incurred. Many
providers will offer multiple e-mail accounts and some will provide space
for a personal web page. Local ISPs sometimes maintain sites with local
information and web links.

Navigating the Web: Web Browsers


Computer software



Graphical



Enables Web navigation



Popular browsers:


Internet Explorer



Netscape Navigator



Mozilla (firefox)



Web browser is software installed on your computer system that allows
you to locate, view, and navigate the Web.



Web browsers are graphical, meaning they can display pictures (graphics)
in addition to text, as well as other forms of multimedia, such as sound
and video.



Although Microsoft Internet Explorer is the most used web browser, there
are other browsers available. All of them have similar tools. Because

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Microsoft products are the main targets for virus writers, an alternative
browser may be less vulnerable.


Internet Explorer is derived from the original browser developed for the
government by Marc Andreeson who went on to start Netscape. The entry
of Internet Explorer over a year later, as an embedded part of the
Windows operating system, was a large part of the anti-trust conviction
suffered by Microsoft in 2000 as it vastly reduced Netscape’s market
share.


The toolbar features are described here. All of these features point to the
power of the web browser. The navigation buttons allow you to travel
down a long string of links and then back all the way out. The refresh
button allows you to get the latest page update quickly. Being able to set a
home page gave birth to the portal concept, where web services offer free
services to entice users to set their homepage to their site. Favorites are a
way to keep track of personal web preferences.

URL


URL:


Uniform Resource Locator
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Unique Web page address



Protocol identifies the means of access



Domain name contains the host and top-level domain



Path identifies the subdirectories within the Web site



A URL is a Web site’s address. It is composed of several parts that help
identify the Web document for which it stands.



The first part of the URL indicates the set of rules (or the protocol) used
to retrieve the specified document. HTTP is most common. Another
popular protocol is FTP.



The protocol is generally followed by a colon, two forward slashes, www
(indicating World Wide Web), and then the domain name. Domain names
consist of two parts: the host and the top-level domain (TLD).



At times, a forward slash and additional text follow the domain name. The
information after the slash indicates a particular file or path (or
subdirectory) within the Web site.

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

The first page in a web site is called the home page. If you type the
domain name into the browser window, the server will find the site and
look for a file called index.htm, the standard name for the home page.
Every web page has a unique URL and is an HTML document. It may or
may not have links to other pages or other web sites.

Current Top-Level Domains
.aero

Members of the air transport industry

.biz

Businesses
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.com

Can be used by anyone

.coop

Cooperative associations

.edu

Degree granting institutions

.gov

United States government

.info

Information service providers

.mil

United States military

.museum

Museums

.name

Individuals

.net

Networking organizations

.org

Organizations (often nonprofits)

.pro

Credentialed professionals



The three-letter suffix in the domain name (such as .com or .edu) is called
the top-level domain (TLD). This suffix indicates the kind of organization
the host is.



The most used is the .com or commercial domain, which can be used by
anyone.



There are also domains for countries outside the United States. For
instance a Web site in Germany has the extension .de and in Britain it is
.UK



The three-letter suffix in the domain name (such as .com or .edu) is called
the top-level domain (TLD). This suffix indicates the kind of organization
the host is.



The most used is the .com or commercial domain, which can be used by
anyone.



There are also domains for countries outside the United States. For
instance a Web site in Germany has the extension .de and in Britain it is
.UK

Hyperlinks


Provide access to other Web pages



Specially coded text or graphics



Cursor becomes a hand with finger pointing upward

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Once you’ve reached a Web site, you can jump from Web page to another
within the Web site or to another Web site altogether by clicking on
specially coded text called hyperlinks



When programming HTML, the Web page author can code any word or
image to be a hyperlink.



Generally, text that operates as a hyperlink appears in a different color
(often blue) and/or is underlined. Sometimes images also act as
hyperlinks.



When you pass your cursor over a hyperlink, the pointer turns from an
arrow to a hand. Clicking the left mouse button when the hand is present
immediately makes a request for the Web site referred to in the code.

Favorites and Bookmarks


List created of favorite Web pages



Easy method of returning to Web pages



Internet Explorer uses Favorites



Netscape uses Bookmarks



While browsing the Web, you may want to remember a site for future
reference. Using the “Favorites” or “Bookmark” feature, the site’s URL is
stored in a special folder.



To add a Web page to your list of Favorites in IE, from within the site you
wish to mark, click on the Favorites menu and select Add to Favorites.



You can modify the name of the Web page on your Favorites list to make it
more meaningful. You can also add subfolders that categorize the
Favorites.

Tabbed Browsing


Found on Firefox and Safari browsers.


Not available on Internet Explorer



Multiple pages in same browser window



A very nice feature that is only available on Firefox and Safari browsers is
tabbed browsing.



With tabbed browsing, Web pages are loaded in “tabs” within the same
browser window. Rather than having to switch between Web pages on
several open windows, you can flip between the tabs in one window.



You can even open several Favorites from one folder and choose to have
them displayed as tabs
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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



A search engine is a set of programs that searches the Web for specific
keywords you wish to query and then returns a list of the Web sites on
which those keywords are found.



Search engines have three parts. The first part is a program called a
spider, which collects data on the Web.



An indexer program organizes the data into a large database.



The search engine software searches the indexed data, pulling out
relevant information according to your search.



Using search engines like Google, users can scan millions of web sites in
seconds, with the search page returning thousands of relevant web pages.
Revenue is generated by offering a side column of paid links that are ties
to certain search requests. For instance, if you put “cat food” in the search
box, Google returns many related sites. Businesses who agreed to pay to
have their link appear when someone requests “cat food” pay a small
amount for every time their ad links appears.

Subject Directories


Web pages organized by topics and subtopics



A subject directory is a guide to the Internet organized by topics and
subtopics. Examples include Yahoo! or the Librarian’s Index.



With a subject directory, you do not use keywords to search the Web.
Instead, after selecting the main subject from the directory, you narrow
your search by successively clicking on subfolders that match your search
until you have reached the appropriate information.



For example, to find previews on newly released movies in Yahoo’s subject
directory, you would click on the main category of Entertainment, select
the subcategory Movies and Films, select the further subcategory Preview,
and then open one of the listed Web sites.

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?
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Is the information current?



Are links available?



Evaluating the content of a web site is important. Before you believe what
the site says or take action based on the information presented, several
questions need to be answered.



Who exactly owns and operates the website?



Who are they trying to reach with their message?



Are the opinions expressed objective, or are they slanted toward one
position or another? If it is slanted, why is it slanted?



Is the information up to date? How often is the site updated?




Do the hyperlinks all work or are some dead-ends?
Like anything else, how well maintained a site is helps determine its
believability.

Communicating Through the Internet


E-mail



Weblogs



Chat rooms



Instant messaging



Newsgroups



A major function of the Internet is communication. It happens in several
ways.



The oldest of the mediums is e-mail. Like the postal system, e-mails are
written documents, with or without attachments, that are delivered
through mail protocols.



Blogs are personal journals that are written and updated periodically for
public viewing.



Chat rooms are public connections where the conversation is written but
seen by all participants as it is entered.



Instant messaging is similar but the connection is private and chosen by
the participants.



Newsgroups are threaded commentary, sort of a public discussion based
on a previous comment about a specific topic..

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E-mail


Electronic mail



Primary means of communication



E-mail accounts





Client-based



Web-based

Spam


Prevention



E-mail has quickly caught on as the primary method of electronic
communication because it’s fast and convenient and reduces the costs of
postage and long-distance phone calls.



Some e-mail accounts are client-based. These programs require a
computer with the correct e-mail client. Client-based systems are normally
tied to a local ISP and use that domain for an address. If a user changes
ISPs, then the e-mail address changes.



Web-based e-mail, on the other hand, finds the messages at a host site
received by and stored on a mail server, and can be accessed from
anywhere. A web-based e-mail address will stay the same no matter what
ISP is used. Free e-mail accounts such as Yahoo! or Hotmail use Web-based
e-mail clients.

Weblogs


Known as blogs



Personal logs or journal entries posted on the Web



Available to the public



Weblogs or blogs are a way for anyone to post their thoughts for public
viewing. Of course posting a blog doesn’t guarantee that anyone will read
it.



Blogging is easy and free. Reading blogs can be very interesting, as they
plug into the unsolicited viewpoints of people who believe they have
something to say.

Chat Rooms


Real time text based conversations



Rooms focus on specific topics or interests

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Identity protection


Username



A chat room is an area on the Web where many people come together to
communicate online. The conversations are in real time and are visible to
everyone in the chat room.



Chat rooms are sometimes theme oriented and sometimes not.



There is no chance for editing out outlandish or offensive opinions or
language.



People in chatrooms choose an identity and therefore are anonymous.



General rules of etiquette (netiquette) include introducing yourself when
you enter the room and specifically addressing the person you are talking
to, refraining from swearing, name calling, and using explicit or prejudiced
language. Users cannot repeatedly post the same text and shouldn’t type
in all capital letters.

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



A chat room is an area on the Web where many people come together to
communicate online. The conversations are in real time and are visible to
everyone in the chat room.



Chat rooms are sometimes theme oriented and sometimes not.



There is no chance for editing out outlandish or offensive opinions or
language.



People in chatrooms choose an identity and therefore are anonymous.



General rules of etiquette (netiquette) include introducing yourself when
you enter the room and specifically addressing the person you are talking
to, refraining from swearing, name calling, and using explicit or prejudiced
language. Users cannot repeatedly post the same text and shouldn’t type
in all capital letters.

Newsgroups
14



Online discussion forums



Post and reply to messages



Newsgroups are sometimes called threaded discussions or discussion
groups. Built around topics or interests, participants read entries from
other participants and respond, each respondent adding something new to
the discussion, creating a thread. A participant can also start a new
thread. Unlike chat rooms, threaded discussions don’t rely on instant
response but on a more thought-out written response. In distance
education classes, threaded discussions are often required, and serve as
the class participation component of a course.



Listservs are similar except that the threads are sent out as e-mails, where
each participant in the thread receives each new posting. They are less
public than newsgroups.

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



Phishing and Hoaxes – Ruses to fool and maybe steal from users.



As the Internet has grown, so have the annoying things on it. Some of
these are dangerous and some merely annoying. Like heavy traffic on the
roads, air pollution, gossip, or any number of annoyances in life, the
Internet reflects the public who uses it, with its share of things to add
stress to a user’s life.



The next few slides will discuss each of these annoyances in more details

Spam


Junk E-Mail



Spam filters



Anti-spam practices



Spam is a particularly difficult problem because there is little that can be
done to control the people who send it. All one needs is a list and a
message. Lists with millions of e-mail addresses can be purchased. There
have been laws passed to make sending spam illegal, but they are difficult
to enforce.

15



One way to avoid spam in your primary account is to create a special email address that you use when you fill out forms on the Web.



A spam filter is an option you can select in your e-mail account that
places known spam messages into a folder other than your inbox. 95% of
spam can be filtered, never reaching your inbox.



You should are careful by reading privacy practices carefully before
registering your name on Web sites, by not replying to spam, and
reporting spam to agencies that filter and fight spam.

Pop-ups


Usually advertising



Pop-up automatically



Pop-up blockers



Pop-up windows are the billboards of the Internet.



Some sites use pop-ups to increase the functionality of their site
(your account balance may pop up at your bank’s Web site, for
example).



There are ways to reduce or eliminate pop-ups. Firefox and Safari
have built-in pop-up blockers. Windows XP (Service Pack 2)
includes a Pop-up Manager to Internet Explorer that allows you to
selectively block pop-ups.



If you feel you need more protection, you can install anti-pop-up software
such as Pop-Up Stopper and Pop-Up Defender.

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

Cookies are a necessary annoyance because they enhance the web
experience and speed up web page loading. When you go to a web page
for the first time the web document drops a small text file in a folder. This
text file saves information about the user and assigns an identification
code so that when the user returns, the same preferences are loaded and
the web site may be more geared to the user. This is critical on sites where
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the content is somewhat chosen to meet the user’s wishes, like in My
Yahoo or other personalized sites.


Although cookies are generally not privacy risks, there have been
cases where the information has been collected and sold to advertisers.

Spyware


Added as a program piggybacked with a requested program



Gathers information, usually about surfing habits



Anti-virus software doesn’t detect it



Anti-spyware programs are required



Often a company will offer something for free, like a screensaver or a
game. Piggybacked with the program is a hidden spyware program that
monitors your browsing and sends this information back to a server.



Anti-spyware software is available from many sources, often for free, and
can effectively find and destroy these annoyances.

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.



If you receive an official looking e-mail from your bank saying that there
has been a software security breach and to help regain control you need
to confirm your username and password, don’t do it. This is one of the
most common scams called phishing. The e-mail is made to look very
official, with logos and signatures, and many unsuspecting customers
have entered their passwords into the return.



Hoaxes often are offers to make millions from a distraught African exprince or to help the victims of a hurricane. It is always best to absolutely
know who is sending the message before responding.

Conducting Business Over the Internet


E-Commerce:


Electronic commerce



Business-to-consumer (B2C)



Business-to-business (B2B)

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Consumer-to-consumer (C2C)



Secure transactions



E-commerce grows in importance everyday, with billions of dollars worth
of transactions.



In business to consumer or B2C transactions, such as Amazon.com, the
end buyer purchases goods or services over the Internet.



In business to business or B2B transactions, businesses sell to one another
.



In consumer to consumer C2C transactions, like Ebay.com, consumers sell
to one another.



Businesses hire security companies such as VeriSign to certify that their
online transactions are secure. Thus, if the Web site displays the VeriSign
seal, you can usually trust that the information you submit to the site is
protected. Another indication that a Web site is secure is the appearance
of a small icon of a closed padlock (IE) or key (Netscape) on the status bar
at the bottom of the screen. Additionally, the beginning of the URL of the
site will change from http:// to https://, the s standing for “secure.”.

Web Entertainment


Multimedia:


Involves forms of media and text


Graphics



Audio



Video



Streaming audio and video: deliver on-demand pictures and sounds
without downloading the whole file.



Plug-in: built-in program and automatically loads



Multimedia is anything that involves one or more forms of media in
addition to text.



All kinds of multimedia are available on the web. One can download music
files, video files, and even movies.



Streaming audio and video can deliver on-demand pictures and sounds.
Sites like CNN.com offer clips from their broadcasts.



Some files require a plug-in program like RealPlayer. In recent versions of
Windows, Microsoft’s MediaPlayer is built-in and automatically loads when
a music file is selected.
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The speed and quality of audio and video on the Web is dependent on the
speed of the Internet connection.

Future of the Internet


Large Scale Networking (LSN):




Research and development of cutting-edge networking and wireless
technologies

Internet2:


Project sponsored by universities, government, and industry to
develop new Internet technologies



Internet2 backbone supports transmission speeds of 10 Gbps

The Internet will continue to have great influence in the future. Greater
bandwidth, wireless access ,and the amalgamation of telephone, TV, and
Internet technologies will bring change and spur new, unforeseen developments.


The U.S. government sponsors research called the Large Scale Networking
(LSN) program, which funds cutting-edge research in wireless and
networking technologies.



Another major effort is Internet2, a cooperative research project of over
200 universities. A major thrust of their research is increased bandwidth
for the whole Internet.



There are also companies working on smell generators and printers that
output taste cards.



We are still in the beginning stages of Internet development. As the
technology becomes more and more part of the fabric of our lives, newer
and better methods for using these tools will emerge. What it all becomes
will be determined by users. Each of us who uses the Internet will help
shape it in the future.

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