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UNIT 3 INTERNET AND ITS APPLICATIONS

Structure

3.0 Introduction to Internet

3.1 Objectives

3.2 Telnet

3.3 FTP

3.3.1 FTP commands

3.3.2 Steps to get/put data from an anonymous FTP site

3.4 Gopher

3.4.1 Usenet

3.4.2 Classification of news groups

3.5 Web Browser

3.6 Search Engines

3.7 Google Search Engine

3.7.1 Components of Google Search Engine

3.7.2 Search tips using Google

3.8 E-mail

3.8.1 Steps to create E-mail account

3.8.2 Spam mail

3.8.3 Voice mail

3.9 Internet Chat Session

3.9.1 Instant Messaging

3.9.2 Voice chat

3.10 Blog

3.11 Internet Development Tools

3.12 Internet Security and Security Measures

3.13 Summary

3.14 Further Readings

3.0 INTRODUCTION TO INTERNET

Internet is a collection of million of computers and computing devices that are all

connected using wire and wireless technologies with star, bus, ring or mesh topologies.

Internet basically operates on TCP/IP protocol. With help of internet user can view

results of examination, access bank account, view stock market details, news, sports, etc,

Ftp allows user to download/upload files across multiple sites. Various web browsers

provides facilities to search on a specific topic, have email account, logs, etc., Internet

security can be provided by firewall and antivirus software.

3.1 OBJECTIVES

After studying this unit, the student is expected to be capable of the following:

• Knows about TELNET

• Knows about FTP

• Knows about GOPHER

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• Will be able to browse Internet

• Use search engines

• Able to give e-mail

• Able to chat

• Create a blog

• Exposure to Internet development tools

• Exposure to Internet security

3.2 TELNET

TELNET (TErminal NETwork) is a protocol that enables the user to log on a different

system and use the resources. The different system (remote) can be located in same

building, city, and country or geographically located in another place of the world. The

system where the user works physically (local system) is called client and the remote

system is called host. Therefore, telnet follows client/server model. To access the host

system, user should know the IP address of that system. If user has login account and

password on remote system, then it is called full-privilege telnet session, otherwise user

can login as guest and share resources (files, memory and CPU) Restricted telnet

connection is called anonymous/guest telnet session

3.3 FTP

FTP (File Transfer Protocol) is a protocol to transfer file(s) from local machine to remote

machine or get file(s). FTP works on a client/server model. On the local machine FTP

client is installed and on the remote machine FTP server is installed. Many FTP sites

allow anyone to log on the server and download related files. Such ftp sites are known as

Anonymous FTP. In restricted ftp sites, user should get login and password from the ftp

server system.

3.3.1 FTP Commands

account, append, ASCII, bell, binary, bye, case, cd, cdup, close, cr, delete, debug, dir,

discount, form, get, glob, hash, help, lcd, ls, macdef, mdelete, mdir, mget, mkdir, mls,

mode, mput, nmap, ntrans, open, prompt, proxy, sendport, put, pwd, quit, quote, recv,

remotehelp, rename, reset, rmdir, runique, send, status, struct, sunique, tenex, trace, type,

user, verbose

3.3.2 Steps to get/put data from an anonymous FTP site

1. FTP to access file in Berkeley education web site. Type ftp

anarres.cs.berkeley.edu at command prompt. Login is anonymous and password is

guest. Any one can access these files. Figure 3.1 depicts successful login.

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Figure 3.1

2. Help at ftp prompt displays a list of ftp commands(figure 3.2).

Figure 3.2

3. ls displays list of files on Berkeley site; Here folders are pub and ucb(figure 3.3)

Figure 3.3

4. cd pub. Change directory to pub (public) directory and ls displays list of file on

pub directory (figure 3.4)

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Figure 3.4

5. cd algebra, change directory to algebra. ls –al, displays list of file in long format

(figure 3.5)

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Figure 3.5

6. pwd – print/present working directory. Binary to get/put files in binary mode and

ASCII to get/put files in ASCII mode. lcd to display local directory path and get

MixedVolume gets the file to local directory c:\. Disconnet to close the

connection to Berkeley. put file.txt is valid, provided the anonymous user can put

files on the destination site. Otherwise put is not valid(figure 3.6)

Figure 3.6

7. Once the ftp task is done, close/disconnect will close the web site connection and

bye will terminate ftp session(figure 3.7)

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Figure 3.7

3.4 GOPHER

Gopher is a tool to search, download and display related data from various sites across

the world. It is a client/server application similar to any web browsers. Presently, WWW

is used with much more search facilities and options compared to gopher. A gopher space

maintains all the related data of various fields .

For a gopher session any one of the following are used:

Browser for Gopher

Client based gopher tool based on the operating system being used

Archie – to search a file related to topic of interest. And later downloaded using FTP

Veronia – Used to access all gopher space for a search also use other search engine

features

CWIS – Campus Wide Information Servers. Using gopher servers, data related to campus

of school, university, office, banks, corporates can be maintained. Now-a-days much

sophisticate www tools are used.

WAIS – Wide Area Information Server. Using Veronia detail searching is not done and

contents of documents are not referred. Using WAIS, details search can be done over

more than 10,000 data bases.

3.4.1 Usenet

Usenet is an application tool which enables the user(s) to join the user group(s) and chat

or discuss on any topic of interest. These groups are called Usenet News Groups. There

are more than 7000 Usenet groups. Each usenet site is maintained by news server and

managed by administrator. Newsgroups are distributed around the globe through news

servers.

3.4.2 Classification of news groups

Comp - computer related features i.e. data bases, architecture, operating systems,

games, etc.,

News - news related network like announce, questions and answers etc.

Rec - recreational topics like sports, books, cinema, dance, music etc.

Biz - business and management related features

Soc - society related issues

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sci - Scientific and technical features like physics, mathematics, chemistry,

biology, etc.

talk - group discussion and debate

alt - wide range of subjects

misc - miscellaneous topics

3.5 WEB BROWSER

An application that runs at user end and facilitates to access many internet resources like

email, search engine, train/air reservation, examination results, net banking, online

shopping, etc., Using URL, the corresponding web site is found. Web browsers operate

using HTTP protocol. Browsers support text, audio, video, animation, etc., features for

displaying web pages. Various types of web browsers are Microsoft Internet Explorer,

Netscape Navigator, Mozilla, Konqueror, Firefox, Safari, Opera, Lynx, etc., With the

help of web browsers user can access search engines, and access emails and use all the

facilities of internet.

3.6 SEARCH ENGINES

Search engines provide the facility to search on any topic across many sites in various

formats. Programs called spiders scan web periodically and maintain latest update in

search engines. Search engine operates on the architecture of search query techniques.

Various types of search engines are AltaVista, Aesop Search, ASK Jeeves, Direct Hit,

Excite, Google, HotBot, Lycos, NorthenLight, SearchKing, WebCrawler,Yep,etc., Each

search engine is application specific and google search is wide generally used.

3.7 GOOGLE SEARCH ENGINE

Images, Video, Maps, News, Shopping, Gmail etc. are components of Google search

engine.

3.7.1 Components of Google Search Engine

1. Browse to http://www.google.com . Search can be done using in any regional or

national languages like Hindi. Default language is English (figure 3.8).

Figure 3.8

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2. To search for any image on any topic, click on Images on http://www.google.com

(figure 3.9).

Figure 3.9

3. To locate any part of the city in any country across the continents, click on Maps

on http://www.google.com (figure 3.10).

Figure 3.10

4. To track latest news in various countries, click on News on

http://www.google.com (figure 3.11).

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Figure 3.11

5. With Orkut, user can create a community of friends and share text, audio, video

and instant message. Orkut mobile helps user to communicate through VoIP

(figure 3.12).

Figure 3.12

6. Google Scholar is an advanced search engine useful for researchers to search for

articles etc. (figure 3.13).

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Figure 3.13

7. Google Translator will translate text from/to any language(figure 3.14).

Figure 3.14

8. Google YouTube to share, upload and view video clips. Video clips can be any

movie clip, user generated sequence of slides, TV clips or any clips. YouTube has

video clips with audio facilities in built. Browse to http://www.youtube.com

(figure 3.15)

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Figure 3.15

3.7.2 Search tips using Google

For searching for any topic user has to type the relevant text and click on search option.

Various options used in google search are:

1. Quotes ( “Mega Structures “ ) - Searches for exact string Mega Structures is

shown in figure 3.16.

Figure 3.16

2. Exclude words ( Bio -Chemistry) – Searches for Bio and not related to chemistry

(figure 3.17).

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Figure 3.17

3. Similar words (~Wireless) – Searches for words like mobile, cell, laptop, cellular,

etc. (figure 3.18).

Figure 3.18

4. Multiple Words (Quantum OR Nano Computing) – Searches for quantum or nano

computing (figure 3.19).

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Figure 3.19

5. Range (Global climate change 2001 … 2005) – Searches for global climate

change from 2001 to 2005.

6. Define (Define YouTube) – Searches for the definition of YouTube (Figure 3.20)

Figure 3.20

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7. Site Specific (VLSI Design site:.edu)- Searches for VLSI Design in all

educational institutions (figure 3.21)

Figure 3.21

8. Link Page (MCA Course: www.ignou.ac.in) – Searches for MCA in ignou web

page (figure 3.22)

Figure 3.22

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3.8 E-mail

E-mail is Electronic Mail. E-mail works on Simple Network Management Protocol

(SNMP). Using e-mail we can send text, audio and video files to one person or a group of

persons. Free E-mail can be created in Google, Yahoo, Hotmail, Netscape, Lycos, etc.,

the following shows sequence of steps to create email account in Gmail which is a part of

Google.com. To create email account in yahoo site, hotmail site or any other site same

sequence of steps can be followed

3.8.1. Steps to create E-mail account

Steps to create E-mail account in Gmail from Google site:

1. In Internet Explorer or any other web browser, type www.google.com and at top

right corner click on sign in option and the page as shown in figure 3.23 appears.

Figure 3.23

2. Click on Create an account option and fill your personal details, as shown below.

Here first name is Student, last name is IGN. Desired login name is student, and

password is given by user and kept confidential (figure 3.24).

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Figure 3.24

3. Security question can be entered as given by gmail or user can have his/her own

question and answer should be given in the below answer option

In case user forgets his/her password, gmail will prompt user this question, and

user should give the correct answer given by him, otherwise gmail will not access

use to login to the system. Word verification meant for confidentiality, so that no

automated tool can create user email account (figure 3.25).

4. After reading terms and conditions, finally user has to click on I accept create my

account option and his email account is created (figure 3.26).

5.

Figure 3.25

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Figure 3.26

Therefore, account of studentign has been created.

The various components of e-mail are explained below:

1. Inbox - Consists of new mail that is not seen and old seen mails in a page. Inbox

is located on left column of gmail. Once the user clicks on the new mail received,

content of the mail is seen on new window (figure 3.27).

Figure 3.27

2. Compose Mail – Meant of composing a mail to a person or group of persons. In

To: recerver’ s email identity (studentignmca@gmail.com) is written

Subject: Welcome you or any other subject regarding user and content of

message is written

Message Box: Here the content of the message is written and fonts, size and color

can be changed.

Once the message is typed, send button at top of In Box is clicked and message is

send to the receiver (figure 3.28).

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Figure 3.28

3. Sent Mail – Gives a list of messages sent by user studentign (figure 3.29).

Figure 3.29

4. Trash – Consists of list of mails deleted(figure 3.30)

Figure 3.30

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5. Contacts – Helps the user to add user name and their email address, postal

address, phone numbers,etc., of their friends, family members, etc. (figure 3.31).

Figure 3.31

6. Settings Change - Click settings option on top right corner of the window to

modify/update user account settings (figure 3.32).

Figure 3.32

3.8.2 Spam mail

Spam is unsolicited junk email send my commercial companies for advertising or by any

unknown person sending email through know email address. Spam decreases email

traffic due to the capacity of unnecessary email flooding. Few spam mails can be detected

and for bulky of spam mails it is more difficult to detect who actually is sending the

spam. Web sites provide spam filter to restrict unnecessary emails to your system.

3.8.3 Voice mail

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Normal e-mail has text, animation and images files. In voice e-mail, the user must record

his/her voice and send. When the receiver opens the e-mail, voice is heard. At both the

ends voice mails need the audio hardware.

3.9 INTERNET CHAT SESSION

Chat is meant for live discussion using text and multimedia features. On the left bottom

of the window, click on chat option; add user email identity with whom we want to chat.

Confirmation comes from the recipient and the chat becomes a two way process.

Internet chat provides a facility to have live chat between many persons or group of

persons. It is a multi way chat technique. Internet Relay Chat (IRC) provides the facility

of internet chat. Each chat group has as separate channel maintained my IRC architecture.

It is normally not meant for one-to-one chat.

3.9.1 Instant Messaging

Mainly meant for one-to-one private communication through messengers or SMS

services in mobile phones. Using instant message text, picture can be send.

Tools that provide instant message features are Microsoft Messenger, Netscape AOL

Instant Messenger, Yahoo Messenger, etc,

3.9.2 Voice Chat

In instant message we can send message, but in voice chat we can have live audio

communication between two persons or group persons using the features of IP telephone

and VoIP (Voice over IP). Many messenger tools support the feature of voice chat also.

Let us assume there are two users given below want to login:

1. Student-MCA

2. Student-IGN

For these two users, email account has to be created in any email provider (yahoo mail,

gmail, hotmail, etc.,) and their respective email identity should be added in each chat

options.

1. Figure 3.33 shows a live chat between two students

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Figure 3.33

2. Using left bottom option users can start voice chat and/or video chat. In this slide,

both the systems do not have audio and video peripherals, as the text appears on

the chat area (figure 3.34).

Figure 3.34

3. Users can use smiley faces for better dialogue (figure 3.35).

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Figure 3.35

4. Above three slides indicate a separate chat window for each user. Here the chat

window is docked out to gmail user, to have full length chat. Docked option is

shown with middle arrow option on right top of chat window. Once the user

minimizes the chat window, it gets docked in to the gmail window as given below

(figure 3.36).

Figure 3.36

3.10 BLOG

A blog is a type of internet website, usually maintained by an individual or a small

company with frequent entries to descriptions of their interest, events, news, game,

movies or to any person sharing his/her views. Material such as text, graphics, audio and

video can also be shared using blog. Blog is normally a one way communication, where

user gives his ideas or comments on that blog site. There are various types of blogs like

science blog, social blog, movie blog, political blog, news channel blogs, etc.

3.11 INTERNET DEVELOPMENT TOOLS

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Java – A programming language enables to run applications from internet. Java applets

provide the facility of GUI and audio/video features. Supports various types of operating

systems and it is operating system independent.

Active X – Active X components and controls are downloaded and run on the computer.

Active X supports all features of internet. IE supports Active x technology.

JavaScript - Script for internet application to create forms, tables and GUI components.

Java script lacks the complexity of programming skills. Java script can call components

create by Java programming.

ASP and .NET also enhances the development of internet.

3.12 INTERNET SECURITY

Computer viruses provide major threat to the system and hamper users work. Memory

and data gets lost and corrupted. Virus slows down CPU and I/O performance. Virus

attack systems data from internet or portable devices like pen drive, CD/DVD drive, etc.

The solution is to have full updated antivirus software.

Cookies are bits of data put on disk when someone visits web site. Cookies keep track of

user login and password and list of files opened by the user. Hackers can access the

cookies and trace personal details about the person.

The following are some of the security measures possible:

• Access control software – Software should be license certified and permission

should be given to users having login accounts

• Antivirus software – Various types of antivirus and spyware software are to

installed to keep system secure

• Firewall – Acts as a protection between computer and external network. Firewall

can be a combination of hardware and software. It is normally installed on the

servers and routers. List of web sites can be listed in the firewall table, restricting

unwanted programs to access the system.

• User login and password – Only users having login and password should use the

systems. Users should not be given any administrator permission to modify any

files.

Session-1 (3 hours)

Question 1: Search for information on CIT programme using atleast two search

engines.

Question 2: Download a video related to the topic titled “How to browse Internet” or

any other technical topic of your interest from Internet.

Question 3: Create an e-mail account using any website which enables creation of

free e-mail accounts.

Question 4: Create your own blog, include information about the seven wonders of

the world on it.

Question 5: Chat with any of your friends.

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3.13 SUMMARY

This unit gives practical idea of Internet and their applications. Using FTP user can

download/upload any file from .edu or any other site. Main functionality of Web

Browsers are explained. Various features of Google search engine and its option are

explained with screen outputs. User can try these and get familiar with google search

options. Various steps to create email account in google are given and the same may be

followed for any email provider. Chat, instant message and voice chat are explained

briefly. Definition of blog and its applications are given. Further, various types of

programming development tools are mentioned briefly to enhance the feature Internet

and its applications. Lastly, Internet security and various security measures are explained.

3.14 FURTHER READINGS

• Internet 101: A Beginner’s Guide to Internet and World Wide Web by Elizabeth

Castro and Wendy G Lehnert; 1998; Addison Wesley Publications

• How the Internet Works:Millenium Edition by Preston Gralla, Sarah Ishida, Mina

Reimer and Stephen Adams; Techmedia Publications

• http://www.google.com

• http://www.wikipedia.org