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 : 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).
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.
FILE TRANSFER PROTOCOL: IIIIs the simplest and most secure way to exchange file over the internet. FFFFiles of any type can be transferred, although have to specify whether the files is ASCII or binary file. TTTThe objectives are : 1.T o promote sharing of files. 2.T o encourage indirect or implicit use of remote computers, 3.T o shield a user from a variations in file storage system among hosts, 4.T o transfer data reliably and efficiently. TTTThe advantages are: 1.I t is very useful to transfer files from one network in an organization to another, 2.I t is an effective way to get a geographically dispersed group to co-operate on a project, 3.I t is a potent and popular way to share information over the internet.
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 ”.
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.
PPP CONNECTION: IPCP – IP control protocol NCP- Network control protocol LCP- link control protocol LAYERED PPP:
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.
Various Technologies and Interfaces GGSM CCDMA WWLL 33G and EDGE SSMS EEmail VVoice Mail CChat VVideo Conferencing
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.
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.
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.
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 (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.
Short Message Services (SMS) is the transmission of short text messages to and from a mobile phone, fax machine and/or IP address.
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.
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.
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.
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
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 server Encycle.msn.com is the address of the server Getinfo/ 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.inhttp://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.
INTERNET SERVERS AND WHAT THEY PROVIDE? SERVERPROTOCOLINFORMATION IT PROVIDES ftpFile transfer protocolText and Binary files that are organised in hierarchical structure like tree httpHyper text transfer protocol Hyper text / Hyper media files (multimedia documents-images, sound and video documents) NewsNetwork news trasfer protocol (NNTP) News group organised in hierarchical structure MailPost office protocol (POP) & simple mail transfer protocol (SMTP) Message sent via Electronic Mail.
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.
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 protection 2. Browser customization. 3. Form processing 4. 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 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
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 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
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 :- 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 NOMINAL CHARGES. FLOSS :- 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.
TERMINOLOGIES PERTAINING TO OSS GNU(GNU’s Not Unix ):- GNU(GNU’s Not Unix ):-GNU PROJECT EMPHASIZE ON THE FREEDOM AND ITS OBJECTIVE IS TO CREATE A SYSTEM COMPATIBLE TO UNIX BUT NOT IDENTICAL 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.
TERMINOLOGIES PERTAINING TO OSS 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
TERMINOLOGIES PERTAINING TO OSS WEB TO ITS FULL POTENTIAL BY DEVELOPING COMMON PROTOCOS THAT PROMOTE ITS EVOLUTION AND ENSURE ITS INTEROPERABILITY. PROPRIETARY SOFTWARE:- IT IS THE SOFTWARE THAT IS NEITHER OPEN NOR FREELY 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.
TERMINOLOGIES PERTAINING TO OSS 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.
TERMINOLOGIES PERTAINING TO OSS SHAREWAREIS NOT SAME THING AS FOSS FOR TWO MAIN REASONS:- THE SOURCE CODE IS NOT AVAILABLE. MODIFICATION TO THE S/W ARE NOT ALLOWED.