INTERNET

INTERNET

BY RAKESH RANJAN KUMAR MANDEEP HARODE

HISTORY OF INTERNET The Internet was the result of some visionary thinking by people in

the early 1960s who saw great potential value in allowing computers to share information on research and development in scientific and military fields. J.C.R. Licklider of MIT, first proposed a global network of computers in 1962, and moved over to the Defense Advanced Research Projects Agency (DARPA) in late 1962 to head the work to develop it. Leonard Kleinrock of MIT and later UCLA developed the theory of packet switching, which was to form the basis of Internet connections. Lawrence Roberts of MIT connected a Massachusetts computer with a California computer in 1965 over dial-up telephone lines. It showed the feasibility of wide area networking, but also showed that the telephone line's circuit switching was inadequate. Kleinrock's packet switching theory was confirmed. Roberts moved over to DARPA in 1966 and developed his plan for ARPANET. These visionaries and many more left unnamed here are the real founders of the Internet.

REAL FOUNDERS OF INTERNET When Senator Ted Kennedy heard in 1968 that the pioneering

Massachusetts company BBN had won the ARPA contract for an "interface message processor (IMP)," he sent a congratulatory telegram to BBN for their ecumenical spirit in winning the "interfaith message

processor" contract.

Charley Kline at UCLA sent the first packets on ARPANet as he tried to connect to Stanford Research Institute on Oct 29, 1969. The system crashed as he reached the G in LOGIN.

Ethernet, a protocol for many local networks, appeared in 1974, an outgrowth of Harvard student Bob Metcalfe's dissertation on "Packet Networks." The dissertation was initially rejected by the University for not being analytical enough. It later won acceptance when he added some more equations to it.

INTRODUCTION The term internet today refers to the network of public

computers running internet protocols. The internet is a global system of interconnec-ted computer

network interchange data by packet switching using the standardized internet protocols(TCP/IP).

It is a network of networks that consists of millions of private and public academic, business and government networks of local to global scope that are linked by coppers wire fibre optic cables wireless connection and other technologies.

The internet carries various information sources such as mail, online chat , file transfer $ file sharing online gaming and interlinked hypertext documents and other sources of world wide web(www).

ADVANTAGES OF INTERNET INFORMATION:- Information is probably the biggest

advantage internet is offering. The Internet is a virtual treasure trove of information. Any kind of information on any topic under the sun is available on the Internet. The search engines like Google, yahoo is at your service on the Internet. You can almost find any type of data on almost any kind of subject that you are looking for. There is a huge amount of information available on the internet for just about every subject known to man, ranging from government law and services, trade fairs and conferences, market information, new ideas and technical support, the list is end less.

ENTERTAINMENT Entertainment is another popular raison d'être why many people

prefer to surf the Internet. In fact, media of internet has become quite successful in trapping multifaceted entertainment factor. Downloading games, visiting chat rooms or just surfing the Web are some of the uses people have discovered. There are numerous games that may be downloaded from the Internet for free. The industry of online gaming has tasted dramatic and phenomenal attention by game lovers. Chat rooms are popular because users can meet new and interesting people. In fact, the Internet has been successfully used by people to find life long partners. When people surf the Web, there are numerous things that can be found. Music, hobbies, news and more can be found and shared on the Internet.

COMMUNICATION The foremost target of internet has always been the

communication. And internet has excelled beyond the expectations .Still; innovations are going on to make it faster, more reliable. By the advent of computer’s Internet, our earth has reduced and has attained the form of a global village.

Now we can communicate in a fraction of second with a person who is sitting in the other part of the world. Today for better communication, we can avail the facilities of e-mail; we can chat for hours with our loved ones. There are plenty messenger services in offering. With help of such services, it has become very easy to establish a kind of global friendship where you can share your thoughts, can explore other cultures of different ethnicity.

E-COMMERCE AND SERVICES E-Commerce:-

Ecommerce is the concept used for any type of commercial maneuvering, or business deals that involves the transfer of information across the globe via Internet. It has become a phenomenon associated with any kind of shopping, almost anything. You name it and Ecommerce with its giant tentacles engulfing every single product and service will make you available at your door steps. It has got a real amazing and wide range of products from household needs, technology to entertainment.

Services:- Many services are now provided on the internet such as online banking, job seeking, purchasing tickets for your favorite movies, guidance services on array of topics engulfing the every aspect of life, and hotel reservations. Often these services are not available off-line and can cost you more.

DISADVANTAGES OF INTERNET Theft of Personal information:-

If you use the Internet, you may be facing grave danger as your personal information such as name, address, credit card number etc. can be accessed by other culprits to make your problems worse.

Spamming:- Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system. Such illegal activities can be very frustrating for you, and so instead of just ignoring it, you should make an effort to try and stop these activities so that using the Internet can become that much safer

VIRUS THREAT :-VIRUS IS NOTHING BUT A PROGRAM WHICH DISRUPTS THE NORMAL FUNCTIONING OF YOUR COMPUTER SYSTEMS. COMPUTERS ATTACHED TO INTERNET ARE MORE PRONE TO VIRUS ATTACKS AND THEY CAN END UP INTO CRASHING YOUR WHOLE HARD DISK, CAUSING YOU CONSIDERABLE HEADACHE.

PORNOGRAPHY:-THIS IS PERHAPS THE BIGGEST THREAT RELATED TO YOUR CHILDREN’S HEALTHY MENTAL LIFE. A VERY SERIOUS ISSUE CONCERNING THE INTERNET. THERE ARE THOUSANDS OF PORNOGRAPHIC SITES ON THE INTERNET THAT CAN BE EASILY FOUND AND CAN BE A DETRIMENTAL FACTOR TO LETTING CHILDREN USE THE INTERNET.

VIRUS THREAT AND PORNOGRAPHY

EFFICIENT USES OF INTERNET

TO FIND INFORMATION:- We can use the Internet to find information about almost anything, using Internet search

engines such as Google and Yahoo. However, we must carefully check the source (website) and quality of the information. An example of good source of general information is wikipedia.org

FILE SHARING:- A file can be put on a “Shared Location” or onto a File Server for instant use by

colleagues. Mirror servers and peer-to-peer networks can be used to ease the load of data transfer.

REMOTE ACCESS:- Computer users can easily connect to other computers and information stores around

the world using the internet. The access can be done with or without security, authentication and encryption, depending on the needs.

Communication and Social Networking:- Internet chat and instant messaging systems allow people to stay in touch in a

convenient way while working at their computers. Messages can be sent and received instantly. In addition, these systems also allow file transfer, as well as voice and video contact.  

Social networking websites allow people to stay in touch with friends and family, and knowing their activities by viewing their profiles. The concept of a social networking website is to store people’s profiles and connecting them between one and another. A personal profile can include pictures and videos to be shared

VoIP:- VoIP (Voice over Internet Protocol) started from an optional two-

way voice chat provided by some of the instant messaging systems that started around the year 2000. The benefit of VoIP is that it can be free or cost much less than a normal telephone call, because the Internet carries that voice traffic. VoIP is surely a cheap solution for long distance call.

HOW DOES INTERNET WORKThe Internet is a global network of

computers each computer connected to the Internet must have a unique address.

Internet addresses are in the form nnn.nnn.nnn.nnn where nnn must be a number from 0 - 255.

This address is known as an IP address.

The picture above illustrates two computers connected to the Internet; your computer with IP address 1.2.3.4 and another computer with IP address 5.6.7.8. The Internet is represented as an abstract object in-between.

NETWORKING INFRASTRUCTURINGpackets travel from one computer to another over the Internet.

packets travel from one computer to another over the Internet.

THE PHYSICAL CONNECTION THROUGH THE PHONE NETWORK TO THE INTERNET SERVICE PROVIDER MIGHT HAVE BEEN EASY THE ISP MAINTAINS A POOL OF MODEMS FOR THEIR DIAL-IN CUSTOMERS. THIS IS MANAGED BY SOME FORM OF COMPUTER (USUALLY A DEDICATED ONE) WHICH CONTROLS DATA FLOW FROM THE MODEM POOL TO A BACKBONE OR DEDICATED LINE ROUTER. THIS SETUP MAY BE REFERRED TO AS A PORT SERVER, AS IT 'SERVES' ACCESS TO THE NETWORK. BILLING AND USAGE INFORMATION IS USUALLY COLLECTED HERE AS WELL . AFTER YOUR PACKETS TRAVERSE THE PHONE NETWORK AND YOUR ISP'S LOCAL EQUIPMENT, THEY ARE ROUTED ONTO THE ISP'S BACKBONE OR A BACKBONE THE ISP BUYS BANDWIDTH FROM. FROM HERE THE PACKETS WILL USUALLY JOURNEY THROUGH SEVERAL ROUTERS AND OVER SEVERAL BACKBONES, DEDICATED LINES, AND OTHER NETWORKS UNTIL THEY FIND THEIR DESTINATION, THE COMPUTER WITH ADDRESS 5.6.7.8. BUT WOULDN'T IT WOULD BE NICE IF WE KNEW THE EXACT ROUTE OUR PACKETS WERE TAKING OVER THE INTERNET? AS IT TURNS OUT, THERE IS A WAY...

IF YOU USE TRACEROUTE, YOU'LL NOTICE THAT YOUR PACKETS MUST TRAVEL THROUGH MANY THINGS TO GET TO THEIR DESTINATION. MOST HAVE LONG NAMES SUCH AS SJC2-CORE1-H2-0-0.ATLAS.DIGEX.NET AND FDDI0-0.BR4.SJC.GLOBALCENTER.NET. THESE ARE INTERNET ROUTERS THAT DECIDE WHERE TO SEND YOUR PACKETS. SEVERAL ROUTERS ARE SHOWN IN DIAGRAM 3, BUT ONLY A FEW. DIAGRAM 3 IS MEANT TO SHOW A SIMPLE NETWORK STRUCTURE

INTERNET INFRASTRUCTURE The Internet backbone is made up of many large networks which

interconnect with each other. These large networks are known as Network Service Providers or NSPs. Some of the large NSPs are UUNet, CerfNet, IBM, BBN Planet, SprintNet, PSINet, as well as others. These networks peer with each other to exchange packet traffic. Each NSP is required to connect to three Network Access Points or NAPs. At the NAPs, packet traffic may jump from one NSP's backbone to another NSP's backbone. NSPs also interconnect at Metropolitan Area Exchanges or MAEs. MAEs serve the same purpose as the NAPs but are privately owned. NAPs were the original Internet interconnect points. Both NAPs and MAEs are referred to as Internet Exchange Points or IXs. NSPs also sell bandwidth to smaller networks, such as ISPs and smaller bandwidth providers. Below is a picture showing this hierarchical infrastructure

If you use traceroute, you'll notice that your packets must travel through many things to get to their destination. Most have long names such as sjc2-core1-h2-0-0.atlas.digex.net and fddi0-0.br4.SJC.globalcenter.net. These are Internet routers that decide where to send your packets. Several routers are shown in Diagram 3, but only a few. Diagram 3 is meant to show a simple network structure. The Internet is much more complex.

Unlike TCP, IP is an unreliable, connectionless protocol. IP doesn't care whether a packet gets to it's destination or not. Nor does IP know about connections and port numbers. IP's job is too send and route packets to other computers. IP packets are independent entities and may arrive out of order or not at all. It is TCP's job to make sure packets arrive and are in the correct order. About the only thing IP has in common with TCP is the way it receives data and adds it's own IP header information to the TCP data. The IP header looks like this:

INTERNET PROTOCOLS

Above we see the IP addresses of the sending and receiving computers in the IP header. Below is what a packet looks like after passing through the application layer, TCP layer, and IP layer. The application layer data is segmented in the TCP layer, the TCP header is added, the packet continues to the IP layer, the IP header is added, and then the packet is transmitted across the Internet.