internet chapter 5 5. objectives of this chapter: discuss the history of the internet describe the...

INTERNETINTERNET

ChapterChapter 55

Objectives of this chapter:

Discuss the history of the Internet

Describe the types of Web sites

Explain how to access and

connect to the Internet

You can…

Imagine the future of the internet

Overview

• This chapter covers– Introduction– History– Internet Software– Internet Services– Future of the Internet

5.1 Introduction

• What is the Internet?– The largest network of networks in the world– Uses TCP/IP protocols and packet switching– Runs on any communications substrate

Introduction

• Also called the Net• One huge global interconnected networks that

comprised millions of computers• A world-wide collection of networks that links

millions of businesses, government agencies, educational institutions, and individual

• Internet services widely use – World Wide Web & e-mail

Introduction (cont’d)

• A technology to link LAN network to a bigger network

• Every computer in the network can directly share data and information with other computers

• Internet Service Provider (ISP) are responsible to provide Internet services:

– Examples: Jaring, MIMOS, TMNet, Telekom, Maxis.net , Time Telekom


• “Galactic” Network– A network that is connected globally where each

computers are able to retrieve data directly and share information

– Every computer on the internet has an IP address (similar to a telephone number) and it is able to exchange data directly with other computers by “dialing” the computer’s address

– The Internet uses packet switching concept where data sent are divided into smaller units known as packets

– Each unit of packet has a number and destination address


• Interoperability– The Internet allows every computer in a network to

operate even tough each remote computers are of different brands and models or in a cross-platform network.

– For example, a user can contact other computers like MAC, Windors PC, UNIX Machine and Mainframe using MAC.

– Telnet is an example of an Internet service where a user can access a remote computer in a network after keying in login and password


High-speed connection

High-speed connection

Slow-speed technology

Slow-speed technology

• How to connect to the Internet?

Dial-up accessmodem in your computer uses a

standard telephone line to connect to the Internet

Dial-up accessmodem in your computer uses a

standard telephone line to connect to the Internet

Digital subscriber line (DSL), cable telephone Internet

services (CATV), cable modem,fixed wireless, and satellite modems

Digital subscriber line (DSL), cable telephone Internet

services (CATV), cable modem,fixed wireless, and satellite modems

Connection is always on—whenever the computer

is running

Connection is always on—whenever the computer

is running

Connection must be established each time you log on. Slow but inexpensive

Connection must be established each time you log on. Slow but inexpensive


– All computers have a unique Internet Protocol (IP) address.

– All computers use TCP/IP protocol to communicate.

– Requires communication device like modem, ISDN adapter, Ethernet card, telephone line

– Download - to transmit data from a remote computer to a local computer

– Upload - to transmit data from a local computer to a remote computer


• TCP/IP– Transmission Control Protocol/Internet Protocol (TCP/IP)

– a combined set of protocols that tells computers how to exchange information over the Internet.

• TCP monitors and ensures correct transfer of data.

• IP receives the data from TCP, breaks it up into packets, and ships it off to a network within the Internet.


– Each Internet services require different protocols.

– Examples like FTP and HTTP sit on top of TCP/IP.

• FTP (File Transfer Protocol) – accessed using FTP browser or DOS prompt

• HTTP (Hypertext Transfer Protocol) – accessed using Web Browser

• POP3 and SMTP – accessed using Mail Browser


• Role of ISP– Access is provided by the Internet Service

Provider (ISP) i.e. Jaring, TMNet.– ISP provides a back bone to the network – either:

• PSTN (Public Switch Telephone Network)• ISDN (Integrated Services Digital Network) or• SONET (Synchronized Optical Network)

– ISP also provide domain name registration for each organization.


• What is a domain name?

Text version of Internet protocol (IP) address

Number that uniquely identifies each computer or device connected to Internet


• Communication Link– Shell Access

• Usually by free shell account providers used for text-based email, IRC.

• Modem and phone line temporary IP

• Computer providers that connect to the Internet (not directly connect to Internet)

– Dial-up Point-to-Point (PPP)

• Modem, phone line, ISDN adapter temporary IP

• Computer Internet


– Cable/Satellites

• Dial-up with modem and phone line temporary IP.

• Faster transmission rate.

– Leased Line

• Modem and dedicated line fixed IP.

• Usually to host Internet/Web Server.

• Support Extranet (external Internet) i.e. Sony Malaysia and Sony Japan.


How the Internet Works• How might data travel the Internet using a cable modem connection?

5.2 History

• 1962– Started from Lickder’s “Galactic Network” idea that

introduced the concept of Packet Switching. RAND researchers concluded that Packet Switching was the best concept

• 1968– Lawrence G Roberts from DARPA formulated the

specifications for Advanced Research Agency Network (ARPANET)

• 1969– ARPANET connected 4 computers in California and

Utah, connecting university and research center with the Department of Defence (DoD) - USA

History

• 1973– ARPANET became an international network

• 1981– ARPANET connected 213 computers

• 1984– Total computers connected to ARPANET reached 1000

• 1987– Total computers connected to ARPANET reached 10,000

History (cont’d)

• Packet Switching– In 1962, Galactic Network introduced the concept

of packet-switching, a new technology to transfer information between 2 distant computers

– Packet-switching technology will break each message/data into smaller unit called packets for speedy and guaranteed delivery

– Each packet carries a unique identification number and the destination address

History (cont’d)

• ARPANET – (Advanced Research Projects Agency Network)

– In 1968, L.G. Roberts from DARPA institute published a specification for Advanced Research Agency Network (ARPANET)

– In 1969, ARPANET successfully connected 4 research computers in California & Utah

– E-mail services was introduced in 1972 – people exchange text messages across a long distance

– In 1973, ARPANET become international network

History (cont’d)

– By 1981, ARPANET has 213 inter-connected computers called the Internet

– In 1982, ARPANET was taken by DARPA and given to NSF (National Science Foundation)

– In 1983, the Internet Protocol (TCP/IP) was introduced by Kahn & Cerf

– By 1984 the network has grown to 1,000 computers and increased to 10,000 in the following 3 years

History (cont’d)

• World Wide Web (WWW)– In 1989, a researcher named Tim Berners-Lee

proposed the idea WWW while working at CERN (a physics laboratory in Europe)

– In 1993, a group of professors and students at the University of Illinois National Center for Supercomputing Applications (NCSA) release mosaic – the first graphically based web browser

History (cont’d)

• What is the World Wide Web (WWW)?

A worldwide collection of electronic documents

Each electronic document is called a Web page

Also called the Web

Can contain text, graphics, sound, video, and built-in connections

A Web site is a collection of related Web pages

History (cont’d)

5.3 Internet Software

• Internet software allows user to use the services provided by the Internet

1. Web Browser– Allows user to view web page and

browse Internet sites

Internet Software

• Example of Web browser

MicrosoftInternetExplorer

Netscape

Firefox Opera

Mozilla

Safari

Internet Software - www

• How does a Web browser display a home page?

Step 1.Click the Web browser program name

Step 2.Web browser looks up the home page setting

Step 3.The Web browser communicates with the ISP’s server to retrieve the IP address. The IP address is sent to your computer.

Step 4.The home page displays in the Web browser

Internet Software - www

2. Pager– A software that allows a individual user to

communicate with other Internet users. Each user has to have the same software in their computer and register at a certain website for them to obtain an unique identity or ID

– The user can then use this software by adding in other user’s ID in his/her pager software to be able to know whether the other user is online on the Internet

Internet Software (cont’d)

– It is usually used to communicate with other “known” individual; as the user needs to know the other user’s ID

– Examples of pager software - Yahoo Messenger, ICQ and MSN Messenger etc

– Some software such as Skype also allows user to communicate via telephone, using Internet as the intermediary medium


3. E-Mail– A software that allows user to read, write and

store e-mails– Examples of e-mail software – Microsoft

Outlook, Outlook Express, Netscape Messenger and Mozilla Thunderbird

4. Internet Relay Chat (IRC)– A software that allows user to use Internet

Relay Chat services (Real-time Chat).– An examples of IRC software – mIRC


5. Download Manager– Allow users to download files to their computers– It can continue to download the file if the user decide to continue

downloading at a later time, or if the user got disconnected and connected again from the network, without having to start the download again from the beginning of the file

– However, to continue downloading from where you stop depends on the server that hosts the file(s). Note that not all server support this process

– The software is also capable of searching other server that hosts the same file(s), which is faster and/or closer to the user’s location.

– E.g. – FlashGet, Download Accelerator Plus, Godzilla and RealNetwork download manager


6. Internet Music Player

– Capable of playing music from the internet

– Some web pages like radio or tv station’s web sites, provide a web based audio and/or video broadcasting/streaming through the internet. It can only be viewed using special software

– Among the popular software are RealPlayer and Microsoft Media Player

– This technology of listening/viewing audio/video through the internet is called “Streaming”


5.4 Internet Services

1. E-mail– Used to send messages digitally through the

internet– Every message delivery should have: address of

the recipient, address of the sender, subject of the message and body of the message

– Email operations include - reply, forward, delete, save and print

– Email will take a few seconds to be sent, it will be stored in the recipient’s email server until the recipient retrieves it. Then the recipient may reply, forward, delete, save or print the email

Internet Services

[email protected]

• User name/ID: azuramasura

• Domain name: jpa

• Top-level domain: .gov

• Two-letter country extension: .my

Internet Services (cont’d)

Other Internet Services

• How does an e-mail message travel?

Step 4.When recipient uses e-mail software to check for e-mail messages, the message transfers from incoming mail server to recipient’s computer

Step 2.Your software contacts software on your ISP’s outgoing mail server

Step 3.Software on outgoing mail server determines best route for data and sends message, which travels along Internet routers to recipient’s incoming mail server

Step 1.Using e-mail software, you create and send message

2. File Transfer Protocol (FTP)– FTP is a protocol used to transfer (download or

upload) files between computers on the internet.– FTP Client software can be used on PCs to

connect to FTP server. – 2 types of modes to transfer files using FTP are:

• ACII (text files)• Binary (usually programs, graphics and

basically all other file types other than text)


– Usually username and password is required to login to FTP service on a FTP server

– Anonymous FTP is one way to connect to FTP server without having to identify yourself. Anonymous FTP example:

• Type the following command on a DOS prompt

ftp ftp.jaring.myEnter the following username an password when askedLogin: anonymous or AnonymousPasswd: <enter your email address>


3. Newsgroup/Message boards


Newsgroup

Many Web sites use message boards because they are easier to use

Online area where users discuss a particular subject Message board

Type of discussion group

4. Chat – Real-time typed conversation that takes place on a

computer– Chat room is location on server that permits users

to discuss topics of interest– Instant Messaging– Example: mIRC, Yahoo Messanger, Skype, MSN

Messanger etc


5. Internet Telephony

– Real-time audio and video technology, such as Voice Over IP (VoIP) and Video Conferencing is getting more popular

– VoIP techology uses three methods:

• PC-to-PC – Using sound card, microphone and computer

• Phone-to-PC

• Phone-to-Phone – Using Telephones that support VoIP

– The quality is not guaranteed (No QoS), There are noise and echo. All calls are charged as local calls.

6. Telnet

– Allows users to login to remote computers using valid username and password. Users need to have an account on the remote computer. Issue the following command in DOS promt

telnet www.upm.edu.my

– A secured alternative to telnet is by connecting to remote computer using SSH (Secure Shell)

ssh www.upm.edu.my

– The remote computer must have Telnet/SSH server running for users to connect to it


7. Ping

– Allows users to check whether a remote computer is up/operational. Type the following command in DOS prompt

ping www.upm.edu.my

– This command or service might not work properly if:• The server or user is behind a firewall and it blocks ICMP request.

• Your ISP does not allow this type of request.

• The server has an embedded firewall on it and it blocks ICMP request.


8. Web Sites– A framework architecture used to share and access

documents that is connected to the internet– Information displayed are intuitive, easy to use and using

interesting graphical interface– Information are exchanged using client server concept.– A web document that interconnects pages is called

hypertext– A text string that links a page to other pages is called a

hyperlink– Hypertext that contains other media (graphics, audio,

video, etc.) is called hypermedia– WWW is a world wide hypermedia and hypertext system


– Every address is unique and is called Universal Resource Locator (URL)

http://www.jaring.my/intro/index.html

– URLs consists of 4 parts:• Protocol: HyperText Transfer Protocol

(HTTP)• Server: Internet domain name• Path: The location of the document

in the server- folder/directory name• Resources name: The filename, usually in one of

these formats html/cgi/sound/movie/graphic

protocol

serverpath File name

Internet Services (cont’d)-website

• What is Search engine

Program used to find Web sites and Web pages by entering words or phrases called search text

Also called a keyword


• What is a hit? Any Web site name that is listed as the result of a search

Step 4. Click link to view Web site

Step 1. Go to search engine

Step 2.Select type of search you wantto run

Step 3. View hits


Advocacy Blog WikiSocial

NetworkContent

AggregatorPersonal

Portal


News InformationalBusiness/Marketing

Educational Entertainment

• 12 basic types of Web sites


A Web site that offers a variety of services from one, convenient location, usually for free

Searching, news, sports and weather, Web publishing, reference tools, stock quotes, maps, shopping, e-mail, and online communities (Web sites that join people with similar interests)

• Portal Web site

• News Web site

Contains newsworthy material Stories and articles relating to current events, life,

money, sports, and the weather


• Informational Web site Contains factual information Created by organizations and government agencies


• Business/marketing Web site Contains content that promotes products or services Allows you to purchase products or services online


• Educational Web site

Some companies offer online training for employees

Some colleges offer online classes and degrees

Offers avenues for formal and informal teachingand learning


• Entertainment Web site Offers an interactive and engaging environment

featuring music, video, sports, games, and more


• Advocacy Web site Contains content that describes a cause, opinion,

or idea



Short for Weblog Uses a regularly updated

journal format to reflect the interests, opinions, and personalities of the author and sometimes site visitors

Video blog (vlog), blogosphere, and vlogosphere

• Blog web site

• Wiki web site Collaborative Web site that allows users to add to,

modify, or delete the Web site content via their Web browser



Encourages members to share their interests, ideas, stories, photos, music, and videos

Media sharing Web site Other example?

Friendster Facebook Hi5 Geni (family tree)

• Online social network

• Content aggregator web site Business that gathers and organizes Web content and

then distributes, or feeds, the content to subscribers for free or a fee


• Personal Web site Web page maintained by private individual Reasons: sharing life experience with the world

or job hunting


• Graphics formats are used on the Web

BMPBMP

GIF(pronounced JIFF)

GIF(pronounced JIFF)

JPEG(pronounced JAY-peg)

JPEG(pronounced JAY-peg)

TIFFTIFF

PNG(pronounced ping)

PNG(pronounced ping)


• What is streaming audio/video?

The process oftransferring audio/video

in a continuousand even flow

Enables you tolisten to music/ watch video

as it downloadsto your computer

Example of a web site offers video streaming: www.youtube.com

Example of a web site offers audio streaming: www.i-bands.net/bandlist.php


Netiquette

• What is netiquette?

Golden Rule: Treat others as you would like them to treat you.

Code of acceptable behaviors users should follow while on the Internet

5.5 HTML Programming Language

Introduction

What is HTML?

HyperText Markup Language

It provides a means to describe the structure of text-based information in a document—by denoting certain text as links, headings, paragraphs, lists, and so on—and to supplement that text with interactive forms, embedded images, and other objects [wikipedia].


HTML Version Timeline

19951995

HTML 2.0HTML 2.0

19971997

HTML 4.0HTML 4.0

19971997

HTML 3.2HTML 3.2

20002000

HTML 4.01HTML 4.01


Web page authoring software

Creates sophisticated Web pages without need to type/edit HTML It generates HTML automatically Examples:

Dreamweaver Flash Microsoft Frontpage Expression Web Silverlight

HTML Editor

HTML documents are plain-text files that can be created using any text editor Example:

Netscape Composer Notepad, word.

Web Page Development

How are special effects and interactive elements added to a Web page?

CounterCountertracks

number of visitors to Web site

Image mapImage mapgraphic

image that points to

URL

ScriptScriptinterpreted

program that runs on client

AppletAppletusually runs

on client, but is compiled

Processing Processing formform

collects data from visitors to Web site

ServletServletapplet that

runs on server

ActiveX ActiveX controlcontrol

small program that runs on

client


Some scripting language :

JavaScript Perl (Practical Extraction

and Report Language) PHP (PHP: Hypertext

Preprocessor) Rexx (Restructured

eXtended eXecutor) TCL (Tool Command

Language) VBScript (Visual Basic,

Scripting Edition)


What are XHTML, XML, and WML?

XHTML XHTML (Extensible HTML)

enables Web sites to be displayed more easily on microbrowsers

XML XML (Extensible Markup Language)

allows developers to create customized tags

WMLWML (Wireless Markup Language)

allows developers to design pages specifically for microbrowsers

Includes features of HTML and XML

Many Internet-enabled smart phones and PDAs

use WML as their markup language

Server sends entire record to client, enabling client to do much of processing without

going back to server

Microbrowser - is a web browser designed for use on a mobile device such as a mobile phone or PDA.

Web page Development

• HTML is composed of tags• Tags - tells browser how to display the

information provided• HTML tags are always enclosed in angle-brackets

( < > ) and are case-insensitive• Generally used in pairs

– Open tag– Closing tag – same tag with / in front– Example: <tag> ... </tag>

Web page Development (cont’d)

• Basic tags

<html>

<body> </body>

</html>

If you view this from the browser, you will see a blank page.


• HTML Header and Paragraph

• See the output of this HTML

<html><body>

<h1>Heading 1</h1><h2>Heading 2</h2><h3>Heading 3</h3><h4>Heading 4</h4><h5>Heading 5</h5><h6>Heading 6</h6>

<p> This is a paragraph</p><p> This is another paragraph</p>

</body></html>

The text between this tag is displayed as a heading.

HTML has six levels of headings, <h1> through <h6>

with 1 being the largest

The text between this tag is

displayed as a paragraph

• HTML Document – linking– Hyperlink - browser highlights the identified text or image

with color and/or underlines to indicate that it is a hypertext link

– Relative linking - the path to the linked file relative to the location of the current file.

<a href=“page1.html”> Click Page 1 </a>

– Absolute linking - linking to documents that are not directly related

<a href=“http://www.fsktm.upm.edu.my”>FSKTM</a>



HTML Links• HTML links are defined with the <a> tag.• Example:

• See the output • Add target=“_blank” to open link in new window

– Example: <a href=“www.upm.edu.my” target="_blank">UPM</a>

<html><body>

<h3>Universiti Putra Malaysia (UPM)</h3>

<p>UPM is a Malaysia’s leading research intensive public university</p>

<a href="http://www.upm.edu.my">Click here to know more about UPM</a>

</body></html> Target page Clickable text


• Create a mailto link– send electronic mail to a specific person or mail alias by including the

mailto attribute in a hyperlink– will only work if you have mail installed

– See output

<html><body>

<p>This is a mail link: <a href="mailto:[email protected]">Send Mail</a></p>

</body></html>


• HTML Images– HTML images are defined with the <img> tag.

– See the output of this HTML

<html><body>

<img src=upmhead.jpg >

<h3>Universiti Putra Malaysia (UPM)</h3><p>UPM is a Malaysia’s leading research intensive public university</p><a href="http://www.upm.edu.my">Click here to know more about UPM</a>

</body></html>

Image source

– GIF• Graphics Interchange Format

• Use for graphics

– JPG• Joint Photographic Experts Group

• Use for photographs

– PNG• Portable Network Graphics

• Expected to replace GIF



• An image as a link– This example demonstrates how to use an image

as a link.

– See output

<html><body>

<a href=http://www.upm.edu.my> <img src=upmhead.jpg> </a><p>Click on the banner to go to UPM’s portal</p>

</body></html>


• HTML Text Formatting tag

• See output

Tag DESCRIPTION

<b> Defines bold text

<big> Defines big text

<em> Defines emphasized text

<i> Defines italic text

<small> Defines small text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<ins> Defines inserted text

<del> Defines deleted text

<s>Deprecated. Use <del>

instead

<strike>Deprecated. Use <del>

instead

<u> Deprecated. Use styles instead

<html><body>

<p><b>This text is bold</b></p><p><strong>This text is strong</strong></p><p><big>This text is big</big></p><p><em>This text is emphasized</em></p><p><i>This text is italic</i></p><p><small>This text is small</small></p><p>This is<sub> subscript</sub> and <sup>superscript</sup></p>

</body></html>


• HTML Style Attribute– The purpose of the style attribute is to provide a common way to style

all HTML elements.

– HTML Style Examples: • style="background-color:yellow"• style="font-size:10px"• style="font-family:Times"• style="text-align:center“

– See output

<html>

<body style="background-color:PowderBlue;"><h1>Look! Styles and colors</h1><p style="font-family:verdana;color:red">This text is in Verdana and red</p><p style="font-family:times;color:green">This text is in Times and green</p><p style="font-size:30px">This text is 30 pixels high</p></body>

</html>

This is the new style attributes. The obsolete old style was:

<body bgcolor=“PowderBlue”>


• Table– Tables are defined with the <table> tag. – divided into rows (with the <tr> tag), and each

row is divided into data cells (with the <td> tag).– The letters td stands for "table data" which is the

content of a data cell. – A data cell can contain text, images, lists,

paragraphs, forms, horizontal rules, tables, etc.

• Tables Tags– <table> ... </table>

- define table in HTML

– <tr> ... </tr>

- specifies a table row within a table

– <th> ... </th>

- defines a table header cell

– <td> ... </td>

- defines a table data cell



• Table demonstration– One row and One Column

– See output

<html><body>

<h1>one Row One column:</h1>

<table border="1"><tr> <td><h1>1,1</h1></td></tr></table>

</body></html>


– One Row Two Column

– See output

<html><body><h1>One Row and Two Columns</h1>

<table border="1"><tr> <td><h1>1,1</h1></td> <td><h1>1,2</h1></td></tr></table>

</body></html>


– Two Row and Two Column

– See output

<html><body><h1>Two Rows and Two Columns:</h1>

<table border="1"><tr> <td><h1>1,1</td> <td><h1>1,2</td></tr><tr> <td><h1>2,1</td> <td><h1>2,2</td></tr></table>

</body></html>

• Tables – more properties– BORDER = X

- add borders to the table– WIDTH=x, HEIGHT=x,

- control the size of the table– ALIGN=left or center or right

- align a table/data to the left,center or right – CELLSPACING-the width of the spacing between cell

and along edges of cells.– CELLPADDING-amount of space inserted btw cell

content and the inner edge of a cell



• HTML List– HTML supports unordered, ordered and definition lists– Unordered List

• marked with bullets (typically small black circles).• starts with the <ul> tag. • each list item starts with the <li> tag

– Ordered Lists• marked with numbers.• starts with the <ol> tag • each list item starts with the <li> tag

– Definition List• It is a list of items (terms), with a description of each item (term).• starts with a <dl> tag (definition list).• each term starts with a <dt> tag (definition term).• each description starts with a <dd> tag (definition description).


• Demonstration of Unordered list

• See output

<html><body>

<h1>An Unordered List:</h1><ul> <li><h1>Coffee</h1></li> <li><h1>Tea</h1></li> <li><h1>Milk</h1></li></ul>

</body></html>


• Demonstration of Ordered list

• See output

<html><body>

<h1>An ordered List:</h1><ol> <li><h1>Coffee</h1></li> <li><h1>Tea</h1></li> <li><h1>Milk</h1></li></ol>

</body></html>


• Demonstration of Definition list

• See output

<html><body><h1>A Definition List:</h1>

<dl><dt>Coffee</dt><dd>Black hot drink</dd><dt>Milk</dt><dd>White cold drink</dd></dl>

</body></html>

End of Chapter 5

internet chapter 5 5. objectives of this chapter: discuss the history of the internet describe the...

Documents

internet slide

internet chapter

individual internet

remote computers

computer s

millions of computers

galactic network

lan network