COMPUTER SCIENCE PROJECT:

COMPUTER SCIENCE PROJECT:

BY:Pruthivi muhilanPawan S RaoPradeepPraveenNishchay

Protocol means the rules that are applicable for a network .

Defines a standardized formats for data packets, techniques for detecting and correcting errors and so on .

It is a formal description of message formats and the rules that two or more machines must follow to exchange those messages .

It supports multitasking.

There are few common protocol :

COMMUNICATION PROTOCOL:

1. HTTP (Hypertext transfer protocol) 2. FTP (File transfer protocol )3. TCP/IP (Transmission control protocol /Internet

protocol)4. SLIP/PPP (Serial line internet protocol / Point to Point

protocol).

HYPERTEXT TRANSFER PROTOCOL:Is a communication protocol for the transfer of

information on the internet and the World Wide Web(WWW).

Is an application level protocol with the lightness and speed necessary for distributed, collaborative, hypermedia information systems.

It is also used as a generic protocol for communication between user agent and gateways to other Internet protocols.

It consists of two distinct items:

The set of request from browsers to servers

The set of responses going back to the other way.

The HTTP has various built-in methods.

HTTP CONNECTIONS

FILE TRANSFER PROTOCOL: Is the simplest and most secure way to exchange file over the

internet .

Files of any type can be transferred, although have to specify whether the files is ASCII or binary file.

The objectives are :

1. To promote sharing of files.2. To encourage indirect or implicit use of remote computers,3. To shield a user from a variations in file storage system

among hosts,4. To transfer data reliably and efficiently.

The advantages are:

1. It is very useful to transfer files from one network in an organization to another ,

2. It is an effective way to get a geographically dispersed group to co-operate on a project,

3. It is a potent and popular way to share information over the internet.

TRANSMISSION CONTROL PROTOCOL /

INTERNET PROTOCOL: Is responsible for verifying the correct delivery of data from client to the server. Data can be lost in the intermediate network.

It keeps track of what is sent, and retransmits anything that did not get through.

If any message is too large for one datagram, TCP will split it up into several datagram, and make sure that they all arrive correctly.

IP operates on gateway machines that move data from department to organization to region and then around the world.

TCP and IP were developed by a Department of Defense (DOD) research project to connect a number of different networks designed by different vendors into a network of networks.

It is based on “ catenet model ”, open connection , built on “connectionless “ technology.

Information is transferred as a sequence of “ datagrams ”.

TCP-A mind map

SERIAL LINE INTERNET PROTOCOL /POINT- TO- PONT PROTOCOL:

SLIP allows a computer to use the Internet protocol with a standard voice-grade telephone line and a high-speed modem.

PPP is used by users connected to a network with a serial connection or modem to establish a temporary network connection. It is usually used to route IP, and sometimes IPX network traffic between the fixed network and the remote user.

SLIP/PPP provides the ability to transport TCP/IP traffic ever serial line between two computers. The home user’s computer has a communications link to the internet. The home user’s computer has the networking software that can speak TCP/IP with other computers on the internet. The home user’s computer has an identifying address(IP address) at which it can be contacted by other computers on internet. E.g. dial up connection.

SLIP CONNECTION:

PPP CONNECTION:

IPCP – IP control protocol

NCP- Network control protocol

LCP- link control protocol

LAYERED PPP:

WIRELESS/MOBILE COMPUTINGWireless communication is

simply data communication without the use of landlines.Mobile communication means that the computing device is not continuously connected to the base or central network.

Various Technologies and Interfaces

GSMCDMAWLL3G and EDGESMSEmailVoice MailChatVideo Conferencing

GSM

GSM is short for Global System for Mobile communications, which is one of the leading digital cellular systems. It was established in mid 1980’s.GSM has now become the international standard in Europe, Australia and much of Asia and Africa.

SIM CARDA SIM is actually a tiny computer

chip that gives a cellular device its unique phone number. It has a memory, a processor and the ability to interact with user. Currently SIM typically have 16 to 64kb of memory, which provides plenty of room for storing hundreds of personal phone numbers, text messages and other data.

CDMA

CDMA (Code Division Multiple Access) uses a spread-spectrum techniques where data is sent in small pieces over a number of discrete frequencies available for use. Each user’s signal is spread over the entire bandwidth by unique spreading code. At the receiver and the same unique code is used to recover the signal.

WLL

Mobile telephone is primarily meant to provide telephone for people on the move. The telephone is meant to keep the person connected while he/she is away from home and office. The key here is universal coverage.

3G AND EDGE3G (Third Generation) mobile

communication technology is a broadband, packet based transmission of texts, digitized voice, and multi at data rates up to and possibly higher than 2 Mbps, offering a consistent set of services to mobile computer and phone users no matter where they are located in the world.

SMS

Short Message Services (SMS) is the transmission of short text messages to and from a mobile phone, fax machine and/or IP address.

E-MAIL

Email is basically short form for electronic mail i.e., messages sent electronically. Electronic mail is changing the world thinks about exchanging information. It has invaded every area of computing and has revolutionized science and business.

VOICE MAILThe voice-mail refers to email systems that supports audio. Users can leave spoken messages for one another and listen to the messages by executing the appropriate command in the e-mail system.

CHAT

Chatting is the most fantastic thing in internet. Chatting is like a text-phone. In a telephonic conversations, you say something, people hear it and respond, you hear their responses on spot and can reply instantly. In the same manner, in chatting, you type a message on your screen, which is immediately received by the recipient., then the recipient can type a message in response to your message, which is received by you instantly.

VIDEO CONFERENCING

The next dimension in Internet communication is the videophone. People who have a multimedia PC with a camera and video comparison hardware, access to Internet over an ordinary telephone line, and videophone software can see each other while talking, which is what is called video conferencing.

Internetworking Terms and concepts

In this section we will be dealing with:

1. WWW (World Wide Web).2. Telnet.3. Web Browsers and Servers.4. URL(Uniform Resource locator) & Domains.5. Web Sites, Web pages & Web Address.6. Web Hosting.7. HTML(Hyper Text Markup Language).8. XML((eXtensible Markup Language).9. DHTML(Dynamic HTML).10. Web Scripting.

WWW - ’world Wide Web’

World Wide Web (WWW) is a set of protocols that allows us to access any document on the net through a naming system based on URL’s.

WWW also specifies a way –The Hyper text Transfer Protocol – To request and send a document over the internet.

Some people mistake WWW for Internet BUT WWW is a small part of Internet. If Internet is a Highway then, WWW is a truck that uses the Highway

User Friendly Multimedia Documents access easy Hyper Text and Hyper Links Interactive –User Network Interface Frames.

WWW ATTRIBUTES

2. TELNET

Telnet is an older Internet Utility that lets you logon to remote computer system.

Basically a Telnet programme give you a character based Terminal window on another system. If you have a permitted Access you can work on that system.

Telnet is an Internet facility to logon to remote computer system

To Run a TELNET Session

o Run TELNET Client – Start ->Run open : telnet

o Connect to TELNET site.o Start browsing o Disconnect TELNET (Alt+ F4 key

combination)

3. WEB BROWSERS & WEB SERVERS

WWW is based upon clients and Servers

WWW client is called Web browser & WWW server is called a Web Server Internet explorer and Netscape Navigator are two most popular web Browsers.

Definition: Web browser is WWW client that Navigates through the WWW and displays Web Pages.

WEB –SITE, BROWSER, PAGES

A location on Net server is called a Website

Each Website has unique address called URL

Eg. Website of Kendriya Vidyalaya Malleswaram has a URL (address) called

http://www.kvmb.org

http://www.kvmb.org/

URL AND DOMAIN NAMES

• The Internet structure is built on a set of rules called Hypertext transfer Protocol (http) and Hypertext markup language (html) . http uses Internet address a special format called Uniform Resource Locator (URL), it looks like type://address/path

• Type specifies the type of server in which the file is located

• Address is the address of the server • Path tells the location of the file on the

server

Eg. http://encycle.msn.com/getinfo/style.asp http specifies the type of serverEncycle .msn.com is the address of the

serverGetinfo/ style.asp is the path of the file

style .asp

SYNTAX ELEMENTS OF URL

URL is an address of a file on Internet.

A File’s Internets address is determined by the following Type of server or protocol Name /address of the server on the

Internet Location of the file on server

Intelligent Browsers like Internet Explorers can display files in any format

Example: DOMAIN NAME SYSTEM (DNS) Consider URL :

http://www.google.co.in http identifies both the protocol and the

server : and // follow protocol server. Next component is the server name

beginning with www, “.com” suffix called domain indicates whether the web site is commercial (“.com”), non profit organisation (“.org”), school or university (“.edu”), branch of government (“.gov”)

In addition to Domain and Protocol, URL may also indicate Country name “.in” refers to India.

http://www.google.com/

INTERNET SERVERS AND WHAT THEY PROVIDE?SERVER PROTOCOL INFORMATION IT

PROVIDES

ftp File transfer protocol Text and Binary files that are organised in hierarchical structure like tree

http Hyper text transfer protocol

Hyper text / Hyper media files (multimedia documents-images, sound and video documents)

News Network news trasfer protocol (NNTP)

News group organised in hierarchical structure

Mail Post office protocol (POP) & simple mail transfer protocol (SMTP)

Message sent via Electronic Mail.

Some common Domains

Sl.no. Domain ID Affiliation

1. com Commercial

2. edu Educational

3. mil Military

4. net Network resources

5. co Company

6. biz Business

7. tv Television

WEB PAGE

Definition: A location on the net server is called

Web page.HOME PAGE- Top level web pages of a

web site WEB PORTAL- It is a web site that

hosts other web sites.Eg.: google, yahoo

WEB HOSTING

Definition: Web Hosting is a means of hosting web server application on a computer system through which electronic content on the internet is readily available to any browser client.

Computer which provides Web Hosting is called Web server. Web Host allows customers to place documents on web server.

WEB HOSTING

WEB HOSTING

FREE HOSTING

SHARED HOSTING

CO-LOCATION HOSTING

DEDICATED HOSTING

FREE HOSTING Some servers offer free of cost publishing of

web pages. Open and check out Pawan’s personal website

http://pawansrao.teacher.tripod.com/index.html

SHARED HOSTING Web hosting company provide some space on its

server for publishing the web pages on charges.



HTML

Everything we see on web is documents written in the special language called html. This language tells the browsers (internal explorer) how to display text pictures on the screen

html is not a word processing tool not a desk top publishing software but just a page layout and hyperlink specification language.

Layout commands are called tags.

Extensible Markup Language, text format, commonly known as XML, created to structure, store, and send electronic information, especially on the World Wide Web. In appearance, XML is similar to Hypertext Markup Language (HTML), which is used to create pages on the Web. The main difference between the two is that HTML determines how Web pages look whereas XML categorizes information on a Web page

XML

XML and HTML complement each other. For example, HTML includes the tags, or markup language, needed to indicate a section of text that should be centered on a screen. XML takes this a stage further and creates tags for certain categories such as dates, names, addresses, prices, and so on.

DHTML(DYNAMIC HYPERTEXT MARKUP LANGUAGE) “Dynamic HTML” is typically used

to describe the combination of HTML, style sheets and scripts that allows documents to be animated.

For example: A piece of text can change from one side or color to another, or a graphic can move from one to another location, in response to some kind of user action such as clicking a button.

WEB SCRIPTING

A web scripting is a script list of commands embedded in a web page . scripts are interpreted and executed by a certain program.

TYPES OF SCRIPTS: the web scripting are of two types : 1- CSS(CLIENT-SIDE SCRIPTS) IN this script the interaction within a web

page is takes place. SOME SAMPLE USES OF CLIENT-SIDE SCRIPT

ARE : a. to get data from user screen or from browser. b. for plying on line game. c. customizing the display of pages in browser

with reload the page.

2- SSS(server- side script) THIS scripts enables the completion or

carrying out a task at the server end and then sending the client end.

UESE OF SSS:1. Password protection2. Browser customization.3. Form processing4. Building and displaying pages created

from a data base.5. Dynamically editing changing or adding

content to a web page

OPEN SOURCE BASED SOFTWARES

THE TERM “OPEN SOURCE SOFTWARE”GENERALLY REFERS TO THOSE CATEGORIES OF SOFTWARES WHOSE LICENSES DO NOT

IMPOSEMUCH CONDITIONS.THESE SOFTWARES GIVE USERS FREEDOM TO RUN THE SOFTWARE FOR ANY PURPOSE, TO STUDY AND MODIFY THE PROGRAM,AND TO REDISTRIBUTE THE COPIES.THERE ARE TWO CATEGORIES:-FREE SOFTWARE ANDOPEN SOURCE SOFTWARE

FREE SOFTWARES

FREE SOFTWARES MEANS THE S/W IS FREELY

ACCESSIBLE AND CAN BE FREELY USED,CHANGED,

IMPROVED,COPIED ANDDISTRIBUTED BY ALL

WHO WISH TO DO.ALSO NO PAYMENT ARE

NEEDED TO BE MADE FOR FREE S/W.

OPEN SOURCE SOFTWARES

OPEN SOURCE SOFTWARE CAN BE FREELY USEDBUT IT DOES NOT HAVE TO BE FREE OF CHARGE.IN CASE OF OPEN SOURCE S/W,THE SOURCE CODEIS FREELY AVAILABLE TO THE CUSTOMER.BUT ITDOSEN’T JUST MEAN ACCESS TO THE SOURCE CODETHE DISTRIBUTION TERMS OF OPEN SOURCE S/WMUST COMPLY WITH THE FOLLOWING CRITERIA:-FREE REDISTRIBUTIONSOURCE CODE

OPEN SOURCE SOFTWARES

DERIVED WORKS INTEGRITY OF THE AUTHOR’S SOURCE CODE. NO DESCRIMINATION AGAINST PERSONS OR

GROUPS. NO DESCRIMINATION AGAINST FIELDS OF

ENDEAVOR. DISTRIBUTION OF LICENSE. LICENSE MUST NOT BE SPECIFIC TO A

PRODUCT. THE LICENSE MUST NOT RESTRICT OTHER

S/W. LICENSE MUST BE TECHNOLOGY NEUTRAL.

TERMINOLOGIES PERTAINING TO OSS

OSS:- REFERS TO OPEN SOURCE S/W,WHICH REFERSTO S/W WHOSE SOURCE CODE IS AVAILABLE TOCUSTOMERS AND IT CAN BE MODIFIED ANDREDISTRIBUTED WITHOUT ANY LIMITATION.AN OSS MAY COME WITH FREE OF COST OR WITH A PAYMENT OF NOMINALCHARGES.FLOSS:- REFERS TO FREE LIBRE(FREEDOM) AND OSS.IT REFERSTO A S/W WHICH IS BOTH FREE

S/W AS WELL AS OPEN SOURCE SOFTWARE.


GNU(GNU’s Not Unix):-GNU PROJECT EMPHASIZE ON THE FREEDOM AND ITS OBJECTIVE IS TO CREATE A SYSTEM COMPATIBLE TO UNIX BUT NOTIDENTICAL WITH IT.

FSF(FREE S/W FOUNDATION):-IT IS A NON-PROFIT ORGANIZATION CREATED FOR THE PURPOSE OF FREE S/W MOVEMENT.FSF HAS FUNDED HAS FUNDED MANY SOTWARE DEVELOPERS TO WRITE SOFTWARES.


OSI(OPEN SOURCE INITIATIVE):-IT IS AN ORGANISATION DEDICATED TO CAUSE OF

PROMOTING OPEN SOURCE SOFTWARE.IT SPECIFIES

THE CRITERIA FOR OPEN SOURCE S/W AND PROPERLY

DEFINES THE TERMS AND SPECIFICATIONS OF OSS.

THE DISTRIBUTION TERMS OF OSS MUST COMPLY

WITH THE OPEN SOURCE DEFINITION BY OSS.

W3C(WORLD WIDE WEB CONSORTIUM):-IT IS RESPONSIBLE FOR PRODUCIND THE S/W STANDARDS FOR WORLD WIDE WEB.IT WAS CREATED IN OCT 1994,TO LEAD THE WORLD

WIDE


WEB TO ITS FULL POTENTIAL BY DEVELOPING COMMON PROTOCOS THAT PROMOTE ITSEVOLUTION AND ENSURE ITS INTEROPERABILITY.PROPRIETARY SOFTWARE:-IT IS THE SOFTWARE THAT IS NEITHER OPEN

NORFREELY AVAILABLE.ITS USE IS REGULATED AND FURTHER DISTRIBUTION AND MODIFICATION IS EITHER FORBIDDEN OR REQUIRWS SPECIAL PERNISSION BY THE SUPPKIER OR VENDOR.ITS SOURCE CODE IS NOT AVAILABLE.


FREEWARE:-THESE ARE THE S/W FREELY AVAILABLE,WHICH PERMIT REDISTRIBUTION BUT NOT MODIFICATION.FREEWARE IS DISTRIBUTED IN BINARY FORM WITHOUT ANY LICENSING FEE.SHAREWARE:-SHAREWARE IS THES/W FOR WHICH LICENSE FEE IS PAYABLE AFTER SOME TIME LIMIT,ITS SOURCE CODE IS NOT AVAILABLE AND MODIFICATION TO THE S/W ARE NOT ALLOWED.


SHAREWAREIS NOT SAME THING AS FOSS FOR

TWO MAIN REASONS:-THE SOURCE CODE IS NOT AVAILABLE.MODIFICATION TO THE S/W ARE NOT

ALLOWED.