COMPUTER SCIENCE PROJECT:

1. COMPUTER SCIENCE PROJECT: BY:Pruthivi muhilan Pawan S Rao Pradeep Praveen Nishchay

2. COMMUNICATION PROTOCOL: • 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 : HTTP (Hypertext transfer protocol) FTP (File transfer protocol ) TCP/IP (Transmission control protocol /Internet protocol) SLIP/PPP (Serial line internet protocol / Point to Point protocol).

3. 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.

4. HTTP CONNECTIONS

5. 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 : • To promote sharing of files. • To encourage indirect or implicit use of remote computers, • To shield a user from a variations in file storage system among hosts, • To transfer data reliably and efficiently. • The advantages are: • It is very useful to transfer files from one network in an organization to another , • It is an effective way to get a geographically dispersed group to co-operate on a project, • It is a potent and popular way to share information over the internet.

7. 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 ”.

8. TCP-A mind map

9. 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.

10. SLIP CONNECTION:

11. PPP CONNECTION: LAYERED PPP:

12. Wireless 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. WIRELESS/MOBILE COMPUTING

13. Various Technologies and Interfaces • GSM • CDMA • WLL • 3G and EDGE • SMS • Email • Voice Mail • Chat • Video Conferencing

14. 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. GSM

15. A 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. SIM card

16. 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. CDMA

17. 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. WLL

18. 3G (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. 3G and EDGE

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

20. 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. E-MAIL

21. The 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. VOICE MAIL

22. 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. CHAT

23. 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. Video Conferencing

24. 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.

25. 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

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

27. 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

28. To Run a TELNET Session • Run TELNET Client – Start ->Run open : telnet • Connect to TELNET site. • Start browsing • Disconnect TELNET (Alt+ F4 key combination)

29. 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.

30. 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

31. 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

32. Eg. http://encycle.msn.com/getinfo/style.asp • http specifies the type of server • Encycle .msn.com is the address of the server • Getinfo/ style.asp is the path of the file style .asp

33. 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

34. 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.

35. INTERNET SERVERS AND WHAT THEY PROVIDE?

36. Some common Domains

37. 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

38. 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.

39. WEB HOSTING

40. 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.

41. 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.

42. XML 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

43. 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.

44. 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.

45. 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.

46. 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: • Password protection • Browser customization. • Form processing • Building and displaying pages created from a data base. • Dynamically editing changing or adding content to a web page

47. OPEN SOURCE BASED SOFTWARES THE TERM “OPEN SOURCE SOFTWARE” GENERALLY REFERS TO THOSE CATEGORIES OF SOFTWARES WHOSE LICENSES DO NOT IMPOSE MUCH 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 AND • OPEN SOURCE SOFTWARE

48. 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.

49. OPEN SOURCE SOFTWARES OPEN SOURCE SOFTWARE CAN BE FREELY USED BUT IT DOES NOT HAVE TO BE FREE OF CHARGE. IN CASE OF OPEN SOURCE S/W,THE SOURCE CODE IS FREELY AVAILABLE TO THE CUSTOMER.BUT IT DOSEN’T JUST MEAN ACCESS TO THE SOURCE CODE THE DISTRIBUTION TERMS OF OPEN SOURCE S/W MUST COMPLY WITH THE FOLLOWING CRITERIA:- • FREE REDISTRIBUTION • SOURCE CODE

50. 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.