• One of the bitter outcomes of the World War II was the Cold War.  By the end of which, in 1945, the United States and Soviet Union emerged as global superpowers. And in order to manifest their supremacy, the two embarked on a nuclear, military, space and technological race.
• The Soviets gained an upper edge by launching the first unmanned artificial satellite into space – the Sputnik, in October 1957. This move took the US by surprise.
• In response to the Sputnik, the US Department of Defence formed the Defence Advanced Research Project Agency (DARPA). This move was to assert its supremacy in military science and technology – which also included a communication project.
• Around the same time, on the technology front, there were developments taking place.  The most powerful invention of the 20th century – the computer, was being built.  The early computers were large and expensive and its use was limited to military and academics.
• Interestingly, it was during the Cold War race in computer technology that the Internet was developed. How? Well it all began with DARPA, but before learning what DARPA had to do with the invention of Internet, it is important to learn about the developments taking place in the computer technology then.

• Speaking of computers around 1957, a computer could work on only one task at a time. This was called batch processing. Now, one task at a time obviously meant a lot of waiting. But then the computer was taking one step at a time.
• As the early computers were big in size, they would occupy an entire apartment. They required cooling and humidity control as tended to heat up, and thus had to be stored in special cool rooms.
• Working directly on the computer wasn’t easy. Programming or instructing it at that time took a lot of manual work.
• The developers came up with an idea; they established a connection with the main computer also known as mainframe. That is, they connected the mainframe to a terminal, and began to program the computer. The mainframe became the Host and the computer connected to the mainframe was called the Terminal.
• But, processing data through this connection took a whole lot of time, since the computer was connected indirectly, lots of bugs began to surface, and fixing and rerunning them made the entire task tedious and time consuming.

• Scientists around the world were working on ways to cut down this time intensive aspect by using the Host-Terminal setup. A solution to this was found by Bob Berner, in 1957.
• Bob Berner was a computer scientist working for IBM. It was Berner who wrote about the concept of time sharing in his article in Automatic Control Magazine. However, the first project to implement a time-sharing system was initiated late in 1957 by John McCarthy, a computer scientist who coined the term Artificial Intelligence.
• But, it was first implemented on a modified IBM 704 and later on a modified IBM 7090 computer.
• Time sharing is the technique of scheduling a computer’s time to carry out more than one task at a time. This meant that now multiple programs could be processed at the same time. So the computer could support multiprogramming and multitasking.
• With time sharing system, developers could connect to the same mainframe computer (host), using multiple terminals and also run different programs from them.
• Thus, Batch processing that could process one task at a time was OUT and Time sharing that can process multiple tasking from different terminals was IN.

• The U.S. president Dwight D. Eisenhower founded the DARPA to undertake high-end research and development projects, and to expand the frontiers of technology and science. Also, to work on futuristic technologies that catered to the needs beyond immediate military requirements.
• Within a year’s time DARPA was renamed ARPA (Advance Research Project Agency), in 1958.
• ARPA in the beginning worked on major national issues that included – space, ballistic missile defence and nuclear test detection.
• However, gradually it transferred the space program to National Aeronautics and Space Administration (NASA) and began to focus on direct energy programs, information processing, and tactical technologies.
• It was ARPA’s attempts in information processing that led to the invention of Internet. And it started with the Galactic Network.

• In August 1962, J.C.R. Licklider of Massachusetts Institute of Technology (MIT) in a series of notes described that social interactions could be possible through networking of computers.
• In the beginning it was just a thought. But, then it is the thought that matters. While discussing the “Galactic Network” that’s what Licklider named the network (short form of the original title – Intergalactic Computer Network), he spoke of a globally interconnected set of computers through which everyone could quickly access data and programs from any site.
• To explore this thought further Licklider was appointed the head of computer research programs at ARPA in October 1962. And while at the agency, he convinced his successors at ARPA, Ivan Sutherland, Bob Taylor, and MIT researcher Lawrence G. Roberts on the importance of the networking concept.
• It was Lawrence G. Roberts who agreed to the entire concept. In 1965 with a view to explore the concept of computer networking, he along with MIT researcher Thomas Merrill connected two computers the TX-2 computer in Massachusetts to the Q-32 in California with a low speed dial-up telephone line creating the first wide area network.
• Ta-da! For the first time, the computers talked to each other. Not a major success though. However, there were a few vital lessons learned.
• The lessons learned were – time shared computers worked well together, running programs and retrieving data from remote machine worked well too, but, it was the circuit switching telephone system which was inadequate for the job.
• Apparently, circuit switching isn’t an effective way of sending a file because it is a methodology wherein at a time only two network nodes can communicate. This kind of concept wasn’t helpful when you are working with more than three computers in a network. Secondly, transferring big files over circuit switching would take forever.
• When you work on a problem, there are chances you will move in circles, but when you are working on a solution, you will come out of the box. Scientists working on the solution developed the Packet Switching protocol.

• To understand what packet switching is, let’s consider this example. Let us say, in a network of computers with terminals A, B, C, D, E, F, G, you have a big file to be sent from terminal A to terminal C.
• Ideally, under circuit switching system the file is sent directly from node A to B and then to C. But in case the size of the file is large, it would consume a lot of time to transfer the file and thereby block the route.
• In packet switching, the big file is broken down into smaller file packets and numbered as packet one, two, three, and sent across via different routes. Once the packets reach the node C they assemble together into the file as sent by node A.
• When the file is sent across the network in small packets, the algorithm (set of instructions) instructs the packet to take the quickest way. It also carries the details of: packet to and packet from. Just in case the packet finds the route blocked or gets stuck in a loop, the packet is then deleted, and the a replacement of the packet is sent from terminal A.
• The concept became a major success when ARPA network of computers also known as ARPANET later used this method.

• Up to this point, knowledge was transferred by people on a one-on-one, one-to-many and many-to-many basis.  In addition, there were several researches being carried out across the country. ARPA was working on channelizing and systematizing knowledge transfer.
• In 1966, ARPA planned a large scale computer network to accelerate knowledge transfer and avoid the doubling up of already existing research. This network was called the ARPANET.
• Like ARPANET, three more concepts were later developed which formed the core elements of the foundation of Internet.
• Concept one was the concept of a Military network of RAND Corporation, US. Concept two was that of a Commercial network of the National Physical Laboratory, in England. Finally, the Scientific network Cyclades in France. These concepts developed one after the other, across the timeframe of 1960s.
• The combination of these networks – scientific, military, and commercial went on to become the core elements of the foundation of Internet.
• Since these networks had their own identity, they were highly sensitive about their data and hence protected it zealously. So, the idea of directly connecting to the main computer of these networks was thought to be unsafe.
• The only way to play safe was to link the host computer of each network to a terminal and subsequently have the terminals connected. Rather than having the data at risk by direct host-to-host connection.
• In devising a way to establish such a connection, the Interface Message Protocol was created.

• In the case of universities, they too were cautious about sharing computers, therefore, a small computer was put out as a terminal that connected to the mainframe.
• Instead of having direct access to the mainframe, this computer would interact with a network of computers and control networking activities, whereas the mainframe would only manage the initialization (registration) of programs and data files.
• The computer that connected to the mainframe and the network of computers became the interface; an interface that managed packet switches efficiently. It soon came to be known as the Interface Message Processor (IMP). Since only the IMP’s were now connected to the network, the network was called the IMP subnet.
• Now most of the host computers began looking out for an IMP and so was ARPANET.  In 1968, ARPANET released a RFQ (Request For Quote) and among the quotes received, an American company BBN won the RFQ.
• A group headed by Frank Heart at Bolt, Beranek and Newman (BBN) together with ARPANET worked on the development of  packet switching.
• The BBN team worked with Bob Kahn, who not only helped to develop IMPs, but in a joint effort with Vinton G. Cerf invented the Transmission Control Protocol (TCP).  Kahn with his BBN team played a major role in the overall ARPANET architectural design.

• The stage was set. Bob Kahn and his team designed the architecture of how the IMP’s were to be connected. Essentially, it comprised of four hosts of computers and all of these were brought together in September 1969.
• As Kleinrock was the one who developed the packet switching theory, his Network Measurement Centre at the University of California, Los Angeles (UCLA) was to be the first node on the ARPANET.
• Stanford Research Institute (SRI) was selected to be the second node and after a month was added to the ARPANET.
• Santa Barbara and University of Utah were the third and the fourth node added to the ARPANET.
• The plan was Kleinrock at UCLA would connect to the Stanford (SRI) computer and try sending data. He began typing “LOGIN” and was hoping the letters to appear on the far-off monitor, at the SRI.
• In order to confirm whether people on the SRI end could see the letters a telephone call was made.
  
  

       Klienrock: “We typed the L and we asked on the phone,”
       “Do you see the L?”
       “Yes, we see the L,” came the response.
       “We typed the O, and we asked, "Do you see the O.”
       “Yes, we see the O.”
       “Then we typed the G, and the system crashed”...

  
  

  Yet a revolution had begun…”

  
  
• By the end of 1969, four host computers established a connection and thus formed the initial ARPANET. This is how the basic ideas of Internet took off.
• However, during the following years, more computers were connected to the ARPANET.

• It was almost four years since ARPANET had hired Bolt Beranek and Newman (BBN) to help in developing the Internet. This team also worked on other interesting projects.
• In March 1972, Ray Tomlinson at BBN wrote the basic “email message send and read software” – SNDMSG.  Like most inventions, this too was developed out of necessity.
• He developed the software SNDMSG for ARPANET developers to facilitate coordination among themselves.
• The software he developed was a “local” electronic message program. The program allowed the user to leave messages on the computer he was using for another person using the same computer. That is, the software facilitated exchange of message on the same machine.
• For instance, at work, you and your colleague share a common drawer. He leaves you a note in the drawer knowing that you will habitually check the drawer and receive the message.
• So, in a way the SNDMSG was a single-computer electronic email program.
• Now you may be wondering, what’s the BIG deal about it?! Saving a message on the same computer in a folder called mailbox, and having it checked by a colleague who shares the same computer.
• Big deal, huh? This would be a blunt way of saying what Tomlinson’s colleague Jerry Burchfiel said – “Don’t tell anyone! This isn’t what we’re supposed to be working on.”
• Now if you haven’t got it right the first time, it doesn’t mean you will not get it right on the next.
• During that time, Tomlinson was working on an experimental file transfer protocol called CYPNET that transferred files among the network computers within ARPANET. He thought why not try running the protocol file CYPNET on ARPANET.
• Tomlinson made minor changes to the protocol program (CYPNET) to use SNDMSG to deliver messages to a mailbox (a file with a particular name) on remote machines. And ta-da!
• In October 1971, the first email was sent between two computers sitting beside each other on the ARPANET.  Considering it was a test email, Tomlinson did not put much thought into what to type, in fact, he casually typed “QWERTYUIOP” and it went down in history as the first word sent on the first email.
• In order to direct the electronic mail to a computer in the network, Tomlinson came up with a way of stating the address of that computer.  He chose the symbol @ and inserted it in between the user’s login name and the name of the user’s host computer. For example: user@host. Yes, it was at this point, the epic symbol @ was first used.
• Ideally, after an invention is developed, it is studied by other scientists who then make contribution to it.
• In the case of the email program, John Vittal from ARPA updated the SNDMSG incorporating three important features: Move – an equivalent of save or delete command, Answer – the reply command, and Forward – sending the email to the person you wish to share the email with.

• Do you wonder how did internet get its name? Around that time, there were notes (memos) published by a body that developed Internet standard called the Internet Engineering Task Force, these memos were called Request For Comment.
• And it was in one of these memos, the RFC 675 – Specification of Internet Transmission Control, December 1974, the term Internet first appeared. It was a short hand for Internetworking.

• The Internetworking got wider and was taken up a notch, when computers began to be connected via satellite. In mid-70s, the Stanford University in Hawaii, U.S. and the University College in London were linked via satellite.
• ARPANET had pioneered packet-switching network, and later also developed the ground-based packet radio networks. With the introduction of the satellite network (SATNET), ARPA developed the packet satellite network.
• As more and more networks were being built it was important to establish a certain protocol. So as to have a standard data format and uniformity in data flow within the network.

Concurrently, in the late 1960s and early 1970s, there were other packet switched networks around like:

     » Mark I at NPL, in the UK,
     » Cyclades,
     » Merit Network,
     » Tymnet,
     » X.25 and public data networks
     » UUCP (Unix-to-Unix Copy)
     » Usenet
     » Telenet

• Now they had a situation: the problem is that most of these networks connected to the ARPANET were built by universities, business and research entities and different networks followed their own network methods thereby creating a great inconvenience. Hence, it was important to unify them and standardise the data format that was exchanged over the networks.
• Besides, ARPA’s study showed that emails composed of 75 percent of the traffic.
• Thus, Robert E. Kahn of ARPANET along with Vinton Cerf of Stanford University got together to work on the problem. It was important to establish a common protocol that could meet the needs of an open-architecture network environment.
• The result of the efforts of Kahn and Vinton Cerf was the formulation of a common interwork protocol – the Transmission Control Protocol / Internet Protocol, in 1975.
• The highlighting feature of TCP was the verification of the file transfer. Besides, it not only controlled the traffic, but also brought about uniformity in inter-networking.
• With time, better versions of TCP/IP were developed – TCP v1, TCP v2, the v3 was split into TCP v3 and IP v3, TCP v4 and TCP v6.

• Going back to the time when ARPA was founded, in 1966, the main purpose of forming ARPA was to fund cutting edge research and development and not to function as a communication utility. So, ARPA approached the U.S. Department of Defence to consider its role.
• In the meantime, inspired by ARPANET’s success, the National Science Foundation (NSF) started its own network – CSNET (Computer Science Network), in 1981.
• As more and more networks were connecting, in March 1982, the US Department of Defence declared TCP/IP as the standard for all military networks. Big American companies like IBM, AT&T and DEC too began to follow the TCP/IP.
• Now, after considering the purpose of ARPA, the U.S. Department of Defence in 1983, separated 45 nodes of the 113 nodes from ARPANET to form MILNET. The remaining 68 nodes were to serve the academic research community.
• Like the NSF, the other branches of U.S. government – the National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) started their own network.
• NASA developed the NASA Science Network, and the Department of Energy developed the Energy Science Network (ESNet). All of the three networks by mid-1980s were developed using the TCP/IP.
• In 1983 as major networks were using the TCP/IP protocol, ARPANET too replaced its protocol Network Control Program (NCP) by TCP/IP, to catch up with developing technologies.

• What began with four hosts was soon becoming a clutter of networks. To have them function well, protocols were developed. But, in the increasing disarray of networks how do you spot your computer?
• A new identity system was introduced. That is, each device was assigned a numeric label called the Internet Protocol (IP) address.
• A separate body, the Internet Assigned Numbers and Authority (IANA) was set to manage IP address allocations globally. This address was not only a name given to your computer, but also an address and route to reach your terminal.

• In 1983, Paul Mockapetris, a computer scientist invented the Domain Name System. In his memorandum, the RFC (Request for Comment) 882, he stated, “as the number of applications to multiple hosts and networks are growing, so will the administrative boundaries, protocols and data formats. Also the number of resources (servers), the number of locations for resources and the diversity of environment may cause formidable problems.”
• So he came up with the Domain Name System (DNS) whereby there would be standard formats for resource data, standard methods for querying (searching) the database, and standard methods for name servers to refresh local data.
• In a way, he streamlined the way networks worked and categorised data under different domains and zones.

• Apparently, on the networks, a huge amount of data was exchanged. Users connected to the Internet would exchange data and soon there was a huge traffic.
• The users ideally, compile the information they would like to share on a document called the webpage. And a set of these related documents or web pages sharing the same address is called a website.
• Now these websites on the basis of its purpose, say educational, commercial, governmental, organisational or other are assigned to a particular server. A server is a computer specifically dedicated to manage a particular task, for example a database server would manage database processing, and an email server will manage email processing and so on.
• Under the DNS, depending on the purpose of your website, a domain name is assigned. For example, if the purpose of your website is educational, it takes the domain name .edu, likewise .gov for government, .com for commercial and so on.
• In 1985, the website symbolics.com for Symbolic Computer Corp, in Massachusetts became the first registered domain.
  
  

• The spread of Internet was getting wider and wider.  At such times, networks following a different protocol needed a translator, a signal convertor to help them connect.
• The node that provided an interface with networks that used different protocol was called the gateway.
• Internet was still following a centralised routing data exchange, where in the data was routed via Exterior Gateway Protocol (EGP).  According to this route, a particular host would play the role of main host.
• But, this kind of routing was like putting all the eggs in one basket. In case of war, if the main host is bombed all the data would be lost.
•  So the best thing is scatter the hosts, and replace the centralised topology with meshed topology.
• The EGP was replaced by the Border Gateway Protocol, in 94.  The BGP allowed the Internet become a decentralised system.

• After understanding core concepts of the elements of the Internet, understanding how the Internet works will be easy.
• As an individual, to connect to the Internet you need to subscribe to an ISP (Internet Service Provider). An ISP hooks your computer to the Internet. Some of the popular ISPs are AOL, Aircell, AT&T etc, you can check for an ISP available locally.
• To begin with, you type the name of a website on the address bar of your browser, say www.xyz.com and hit enter.
• Your request is picked up by your ISP and is soon directed to the Domain Name Server. The DNS has the list of IP address so it quickly directs your request to the server where your request can be met.  The request reaches the server which searches for the request made, finds the data, breaks it into packets and returns it to your terminal. All of this happens in matter of seconds.
• The reason it happens quickly is because of two reasons: data packets and protocols. The Internet follows protocols – TCP/IP. These protocols lay norms and standards for data format and create a framework within which the computers in the network should function.
• While returning your request, it sends your file in small data packets through different but quickest routes.  These packets move faster over the network, as they are sent in 1000 and 1500 bytes.
• Internet by nature could not be contained within boundaries and continent. Simultaneously there were developments taking place in Europe.

• The technology of networking of computers was soon catching up in Europe. The CERN (French for, European Organisation for Nuclear Research) around mid-1980s began installation and operations of TCP/IP, so as to connect with major internal computer systems and workstations, PCs, and its control system.
• Apparently, until 1989, the CERN TCP/IP intranets (a network of computers within an organisation) were not connected to the Internet.
• But this was soon changing; CERN opened its first external TCP/IP, and with this, it got connected to the Internet.
• In the process of adding more networks, the use of technologies such as X.25 and UUCP Net connected the ARPANET to Australian Universities.
• X.25 is a standard protocol suite for packet switching over Wide Area Network, a network of computers covered over broad area.
• UUCP Net is a suite of computer programs and protocols that facilitates remote execution of commands and transfer of files, email and net news between computers.
• Networks began connecting with networks like the Japan University Network (JUNET) connected to the NSFNET in 1989.

• By now the National Science Foundation network (NSFNET) became the major network; it was a network of networks connected to academic users along with the ARPANET.
• NSFNET was a major part of the Internet backbone as it connected to the supercomputer centres at 56,000 bits per second.
• Since 1986, the network included big names like University of Illinois National Center for Supercomputing Applications (NCSA), Cornell University Theory Center, University of Delaware, and Merit Network.
• The thing about technology is you are never on the same page for long. When it all started, the IMP’s and the transfer protocols had the early Internet working. Later all that was taken care of by its advanced version, the NSFNET; as the result, in late 1989, the ARPANET was shut down and the NSFNET took over.

• The idea of the World Wide Web is said to have come from the book, The Garden of Forking Paths written by Jorge Luis Borges.
• It is said the book is about a story that has multiple layers to it, the reader picks up links one after the other, to move from one node of text to the next, and gradually arranges the story.
• In a way it was very much like the hypertext (a text that links you to other text) over the Internet.
• In the world of Internet, Ted Nelson an American sociologist, in early 1960s had coined the term “hypertext.”  He used it while talking about the model he developed that would create and use linked content.  That is when a wider audience learned about the idea of hypertext.
• But, it was only in 1990, this concept found a wider application when Tim Berners-Lee developed the World Wide Web system.
• The four main elements of the system are:
       » HyperText Transfer Protocol
       » HyperText Markup Language
       » Web Browser
       » Uniform Resource Identifier
  
  

• It so happened, in 1980, that Berners-Lee had written a software program ENQUIRE that would facilitate updating and sharing information among physicists at CERN. It was a program that supported simple hypertext and link the text to other text.
• For another eight years, no major development took place on this front, until it dawned on Berners-Lee that all he had to do was to connect the hypertext idea with the Transmission Control Program and the Domain Name System.
• To connect the hypertext with TCP and DNS, Berner-Lee developed a program called the HyperText Transfer protocol program. This program allowed the user to move from link to link.
• Previously, it was about sharing a file over the internet; for that the packet switching was an ideal way of routing file over the network.
• But now, the concept was changing, it was about moving between web pages, for this the packet switching would not work.
• By then, there were different types of computer in the market like the Macintosh, UNIX machines, Personal Computers and simple terminals. Transferring data over different types of computer using the packet package was impractical.
• Hence, he built the system World Wide Web under which he wrote a new application protocol – HTTP ( HyperText Transfer Protocol). This would facilitate collaboration, distribution and exchange of hypermedia (multimedia based files) information system.
• Under this system, interlinked documents could be accessed over the Internet.
• It was designed to enable users to access, retrieve and view documents and other resources on the Internet.

• As per Berners-Lee’s new system, documents that carried hypertext link were displayed on a webpage.
• And this webpage could be developed using the Hypertext markup language.
• But, to view the webpage, he developed a program called a web browser.
• Today, there are a number of web browsers in the market to name a few – Internet Explorer, Google Chrome, Mozilla Firefox, Safari and many more, but did you know that it was Berners-Lee who developed the first web browser?
• He named the browser World Wide Web.

• Another element of the World Wide Web system was the URI (Uniform Resource Identifier).
• Over the Internet, a web page carries image, video or other piece of content. Series of web pages belonging to the same business, university or any other identity is called a website. Considering a great amount of information was going to be exchanged, there would be millions and millions of websites floating in cyberspace.
• In order to classify these websites and to identify them with information resource stored in the web server, a Uniform Resource Identifier was developed.
• An URI was a string of characters used to identify information resource over the Internet. It is similar to the ISBN (International Standard Book Number) given to a book. Like the ISBN gives unique identification to a book, the URI gives an identity to the web source.

• Berner-Lee’s system of the World Wide Web changed the dynamics of the Internet. This system not only changed the way data was exchanged over the network, but also added speed and volume to data transfer over the internet.
• Everything was sorted out. The web resource of information was stored on server known as Web Server. The Uniform Resource Indicator made fetching and delivering of data easy and quicker.
• Finally, the system was to be put to test. Apparently, the entire system was first tried on Steve Job’s computer NeXT.
• The stage was all set, on 6th August 1991, at the CERN, the first website was built and put online. The address of the world first-ever web site and web server was run on the NeXT computer at CERN.
• The World Wide Web system was a complete package as it had a protocol, a browser, a web server and a URI.
• The first web page address typed in the address bar read as First Web Page, on this link you had information regarding the WWW project.  The text here provided an explanation of what the World Wide Web was that is what was HTTP, how one could use the browser, and how to setup a web server.
• The entire WWW setup was a success, thus soon the word internet was synonymously with the word, Web.
• By the early 1990s, the phenomenon called the Internet took off and the world slowly began to move online.

• Internet has come a long way, from a small network of computers to the connection of networks across the nations and continents.
• In Jan 2010, the internet took yet another big leap. The first live Internet link into the low earth’s orbit was established when astronaut T.J. Creamer posted the first unassisted update to his Twitter account from the International Space Station. This goes to show that the “net” short for Internet has now reached out to space.
• The point from where Internet became popular with people was – its killer application the Email. Internet, with its growing utilities and applications, found great acceptance in government offices, commercial settings, civil society and individuals.
• In present times, we live in an on-click world because of the Internet. Right from shopping, to e-learning, trading stock, Internet medicines, online surgeries, entertainment and almost everything under the sun is now accessible on the tip of your finger, courtesy: The Internet.
• With the introduction of mobiles and advance technology, the Internet is no more restricted to computers alone. Mobiles phones, certain household appliances, cars and state-of-the-art manufacturing processes and operations are connected to the Internet.
• Now that Internet has linked into the low orbit, the next thing you know it will go the inter-planet way and play an instrumental role in building a human civilization on other planet(s).
• In merely 50 years, Internet has made its way from a connection among three universities and a research institute to linking planet earth to space. That time too will come along when the two ‘I’s (eyes) – Internet and Infinity would meet.