8/4/2019 Lecture 01 2

1/16

Introduction to Internet

Prof. Indranil Sen Gupta

Dept. of Computer Science & Engg.

I.I.T. Kharagpur, INDIA

Indian Institute of Technology Kharagpur

Lecture 1: Introduction to Internet

On completion, the student will be able to:

1. Define the Internet.

2. Explain how the Internet has evolved.

3. Identify the distinguishing characteristics of the Internet.

4. Summarize the popular Internet applications.

5. Identify the Internet resources and documents (RFC

documents).

6. Identify the topics that would be covered in the presentcourse.

8/4/2019 Lecture 01 2

2/16

What is Internet?

The network formed by the co-operativeinterconnection of a large number ofcomputer networks.

Network of networks.

No one owns the internet

Every person who makes a connectionowns a slice of the Internet.

There is no central administration to theInternet.

Network

Network

Network

Network

Network

Network

8/4/2019 Lecture 01 2

3/16

So what is it actually?

A community of people who use and develop the networks.

A collection of resources that can be reached from those

networks.

A setup to facilitate collaborationamong members of the research and

educational communities, world-wide.

The connected networks use theTCP/IP protocol.

Key Milestones in Evolution

1950s

ARPA (Advanced Research ProjectsAgency)

1970

ARPANET creates precursor toTransmission Control Protocol (TCP)

1971

Universities added to netTelnet and FTP are available

1972

First electronic mail message sent

8/4/2019 Lecture 01 2

4/16

Contd.

1973-

ARPANET connected to England andNorway

1974-

TCP starts being used for communicatingacross a system of networks

1982-

US DoD starts building defense data

networks based on ARPANET technology 1983-

ARPANET splits into ARPANET and MILNET

Contd.

1983-Internet now in place

TCP/IP standardized

1986-National Science Foundation (NSF)

implements NFSNET; a system ofregional network of routers connectedover a backbone network

1991-Archie and Gopher released

8/4/2019 Lecture 01 2

5/16

Contd.

1992-Internet links more that 17,000 networks

in 33 countries; 3 million hosts

1993-World Wide Web is launched

1995-Interconnected network providers start

offering service

1995-About 30 million users

Growth of Internet

010000000

2000000030000000400000005000000060000000700000008000000090000000

100000000

1989 1992 1995 1998 2001

ExponentialGrowth

Numberofhosts

8/4/2019 Lecture 01 2

6/16

Important Internet Applications

Telnet

File Transfer Protocol (FTP)

Electronic Mail (Email)

Gopher

Internet Relay Chat (IRC)

Usenet News

World Wide Web (WWW)

Request for Comments (RFC)

8/4/2019 Lecture 01 2

7/16

Internet standards and RFCs

The Internet Society

Internet Architecture Board (IAB)

Internet Engineering Task Force (IETF)

Internet Engineering Steering Group (IESG)

Request for Comments (RFC) Publication

The actual development of new standardsis carried out by working groups charteredby the IETF.

Membership is voluntary.

The process involved:

The working group makes a draftversion of the document.

Places it in the Internet Draft onlinedirectory.

Kept there for six months, and review

and comments on the draft obtained.

8/4/2019 Lecture 01 2

8/16

The IESG may approve the publication ofthe draft as an RFC during this period.

Or else it is withdrawn from thedirectory.

The working group may subsequentlypublish a revised version of the draft.

RFC Publication Process

Internet Draft

ProposedStandard

Experimental Informational

DraftStandard

InternetStandard

Historic

Light shaded

boxes aretemporary

states

8/4/2019 Lecture 01 2

9/16

Important RFCs

RFC821: Simple Mail Transfer Protocol

RFC791: Internet Protocol

RFC793: Transmission Control Protocol

RFC2616: Hypertext Transfer Protocol 1.1

RFC2045: MIME

RFC1321: MD5 Message Digest Algorithm

RFC1866: Hypertext Markup Language 2.0

RFC2437: RSA Crypto Specifications 2.0

RFC2631: Diffie-Hellman Key Agreement

Where to find the RFCs?

Available in many web sites.

http:// www.faqs.org / rfcs /

http:// www.ietf.org / rfc.html

http:// www.rfc.net

8/4/2019 Lecture 01 2

10/16

Topics to be Covered

Module 1

Introduction

Lecture 1

Introduction to Internet

Lecture 2

Review of network technologies

8/4/2019 Lecture 01 2

11/16

Module 2

Transmission Control Protocol /Internet Protocol

Lecture 3

TCP/IP Part I

Lecture 4

TCP/IP Part II

Lecture 5

TCP/IP Part III

Module 3

Addressing and Routing

Lecture 6

IP subnetting and addressing

Lecture 7

Internet routing protocols Part I

Lecture 8

Internet routing protocols Part II

8/4/2019 Lecture 01 2

12/16

Module 4

Common Internet Applications

Lecture 9

Client-server concepts, DNS, Telnet, FTP

Lecture 10

Electronic mail

Lecture 11

World wide web Part I

Lecture 12World wide web Part II

Module 5

Creating Web Pages

Lecture 13

HTML Part I

Lecture 14

HTML Part II

Lecture 15

HTML Part III

Lecture 16

XML

8/4/2019 Lecture 01 2

13/16

Module 6

Designing Interactive Web Pages

Lecture 17

HTML forms

Lecture 18

Image maps

Lecture 19

CGI scripts

Lecture 20Other technologies

Module 7

Practical Extraction and ReportingLanguage (PERL)Lecture 21

PERL Part I

Lecture 22

PERL Part II

Lecture 23PERL Part III

Lecture 24

PERL Part IV

8/4/2019 Lecture 01 2

14/16

Module 8

Javascript

Lecture 25

Javascript Part I

Lecture 26

Javascript Part II

Lecture 27

Javascript Part III

Module 9

Java and the Internet

Lecture 28

Java applets Part I

Lecture 29

Java applets Part II

Lecture 30

Client-server programming in Java

8/4/2019 Lecture 01 2

15/16

Module 10

Internet Security

Lecture 31

Intranet, extranet, firewall

Lecture 32

Basic cryptographic concepts Part I

Lecture 33

Basic cryptographic concepts Part II

Lecture 34Basic cryptographic concepts Part III

Module 11

Miscellaneous Applications

Lecture 35

Electronic commerce

Lecture 36

Real-time applications, IP telephony

Lecture 37

Web crawler, search engines

Lecture 38

Miscellaneous topics

8/4/2019 Lecture 01 2

16/16

Module 12

Case Studies

Lecture 39

Web-based mail, proxy server

Lecture 40

Connectivity to backend databases