Despite Al Gore’s claims to the contrary, the Internet was not originally invented by or created by a single person. The Internet as we know it today is a combination of a number of concepts that have ultimately been merged together to provide the service. Tim Berners-Lee (or Sir Timothy John Berners-Lee as officially known in the UK), is a British computer scientist who is credited with inventing the World Wide Web. First proposed in March 1989 and later implemented on Christmas Day, 1990 with the assistance of Robert Cailliau and a CERN student, he was able to implement the first communication between a client and server using the HTTP (Hypertext Transfer Protocol) on the Internet. To get to this point; however, required a significant amount of work by other academics, researchers, and organizations in the underlying technologies that now comprise the web.
Who Thought of the Internet First?
Leonard Kleinrock is credited with crafting the first public concept for the Internet with his paper, “Information Flow in Large Communication Nets” on May 31st, 1961. Dr. Kleinrock’s work in this timeframe (which comprised his PHD work at MIT) was to establish the mathematical theory of packet-based networks. In the same timeframe, J.C.R. Licklider would become the head of the Information Processing Techniques Office (IPTO) United States Department of Defense Advanced Research Projects Agency or at DARPA. He would provide his vision or dream of a world-wide network and would provide the vision that would later become ARPANET. Since Licklider was not an experienced computer programmer; however, he would recruit Lawrence Roberts to lead the team that would eventually create and deploy ARPANET in 1967. Roberts would be the first scientist or engineer to implement the packet switching network that Kleinrock first created. This form of packet switching is still used as the primary means of transferring information to this day on the web.
Origins of ARPANET
Over the 1960s, ARPA and the Massachusetts Institute of Technology (MIT) corroborated to share technology and research information. Ivan Sutherland and Bob Taylor would perform a lot of the precursor work to the ARPANET by connecting separate computers via phone network with researchers in Santa Monica, University of California at Berkeley, and MIT. In 1966, Larry Roberts from MIT would introduce the ARPANET which would allow computers to be linked over long distances. In 1969, colleges were permitted to become a part of the network nodes with UCLA and Stanford being early adopters. The network was further expanded in 1971 and by 1973 had a node in London.
Early Networking Equipment
On August 29, 1969 the first network switch was sent to UCLA for use and was called an IMP (Interface Message Processor). The first data was moved to the switch from the UCLA host on September 2nd, 1969. The IMP’s were developed by BBN technologies under contract to ARPA with the team led by Frank Heart. The IMPs were designed to function as gateways with the purpose to connect local resources. At each deployment site, the IMPs would conduct storage and forwarding of packet switching functions. The devices were connected via modems that were connected through leased phone lines running at an initial speed of 50 kbit/second. The host computers at each location were then connected to the IMPs via serial communication interfaces. The design to implementation of the IMPs was accomplished in just 9 months. The first IMPs made use of a Honeywell DDP-516 computer that was configured with 24KB of expandable core memory along with a 16 channel DMC (Direct Multiplex Control) direct memory access unit. The purpose of the DMC was to establish a communications interface between the host computer and modem. The early IMPs could support up to four local computer hosts and support communications with up to six remotely located IMPs.
In the initial deployment of ARPANET there were four IMPs. These were sent to UCLA, Stanford, University of California at Santa Barbara (UCSB), and the University of Utah. The first message transmitted on the ARPANET was sent at 10:30 PM / 2230 by UCLA student Charley Kline from Boelter Hall. Under the supervision of Leonard Kleinrock, he transmitted from the SDS Sigma 7 Host computer to the Stanford Research Institute’s SDS 940 Host computer. His message text was intended to be “login” by the system crashed after the letters “lo” were sent. As a result, the first message transmitted on ARPANET was “lo.” Approximately one hour later after recovering from the crash, a full “login” message was sent. The first permanent ARPANET link would be established on November 21st, 1969 between UCLA and the Stanford Research Institute. On December 5th, 1969 the entire four-node network would be established.
Development of Email
Often overshadowed by the development of ARPANET, the first use of network email occurred in 1972 by Ray Tomlinson. In 1968, Tomlinson was working for the U.S. Defense Department as a computer engineer. He first developed an application called SNDMSG whose purpose was to allow ARPANET users to relay messages. At first, the application was only used to allow communications between users of the same computer. The transfer protocol, CYPNET, was used as an enabler in the SNDMSG application. This would allow SNDMSG to send and receive email to any computer connected to the ARPANET. In order to extend the addressing to the network, Tomlinson picked the “@” symbol to combine user names and the host names. This resulted in the notation of “user@hostname” that is still used to this day for email addressing. The first email message that Tomlinson sent was “QWERTYUIOP.” The program has very basic functionality; but was the origin of the email transactional model that continues to be used today. The service would then be connected to the File Transfer Protocol (FTP). Later, this would evolve to being replaced by the Simple Mail Transfer Protocol (SMTP). The FTP service continues to be used today for downloading and uploading files on the Internet and local networks. MIT developed a similar message sending system in 1961 with the Compatible Time Sharing System (CTSS). CTSS allowed users to collect and share files while on the network. SNDMSG would be the first application to send messages between users on different computer networks.
Combining Individual Networks
After the deployment of ARPANET, a number of different networks started to be deployed around the world to include NPL, Merit Network, and CYCLADES. With so many different networks and networking methods emerging, there became a need for an underlying technology to connect or unify them. Robert E. Kahn from DARPA and ARPANET would recruit Vinton Cerf from Stanford to work on the problem. In 1973, the design of TCP resulted and would be published along with the assistance of Yogen Dalal and Carl Sunshine in December of 1974 as RFC 675, Specification of Internet Transmission Control Protocol. This key advance in networking technology would permit the difference in network protocols to be hidden by using a common internetwork protocol. TCP would also shift the responsibility for network reliability to the hosts vice with the network. This RFC would also contain the first use of the term “internet” as shorthand for “internetworking” and was used as an adjective. DARPA would go on to fund development of follow-on prototype software and on November 22nd, 1977 a three network demonstration was conducted between the Packet Radio Network, the Atlantic Packet Satellite network, and ARPANET. TCP/IP would emerge in mid-1978 and be published as standards 791, 792, and 793 in 1981.On January 1st, 1983, TCP/IP would become the only approved protocol to be used on ARPANET supplanting the previously used NCP protocol.
What was the First Commercial Network?
The first commercial version of ARPANET produced was Telnet which was introduced in 1974. Telnet is considered by many to be the first Internet Service Provider (ISP), although the term was not used at the time. Telnet is now known as a client-server protocol that is based on a reliable connection-orientated transport. It is used to establish a TCP connection via port 23 that has a Telnet server application waiting to receive incoming transmissions. Before the advent of TCIP/IP, the service was run using the Network Control Program (NCP) protocol and was not based on a RFC definition. Since that time, there have been a number of extensions to Telnet developed which have become international standards (IETF STD 27 through STD 32).
When Was Ethernet Developed?
Robert Metcalf is credited with developing Ethernet while at Xerox PARC between 1973 and 1974. The idea was first documented in a memorandum that Metcalf published on May 22nd, 1972. In 1974, Xerox filed a patent application that listed David Boggs, Chuck Thacker, Metcalfe, and Butler Lampson as the inventors. Ethernet is considered to be a family of networking technologies applicable for local networks and would later be introduced commercially in 1980 and is now standardized in IEEE 802.3. When systems or computer communicate over Ethernet, a stream of information is divided into individual packets that are referred to as frames. Each of the frames contains a destination and source address along with error checking data to ensure reliable delivery of information with an original data rate of 10 megabits per second. With succeeding improvements in twisted pair development, deployment of fiber optic links, and hubs and switches, these rates have increased to 100 gigabits per second.
When Was DNS Invented?
Prior to the invention of DNS in 1982, ARPANET made use of a hosts.txt file to lookup a simpler version of a computer host’s numerical address on a network. The hosts.txt file was retrieved from a computer at RI. As the number of computer hosts continued to grow; however, the use of the hosts.txt file quickly became unmanageable and could not scale. As a result, Paul Mockapetris invented the Domain Name System (DNS) and wrote the first implementation. DNS is designed to be a hierarchical, distributed naming system that can be used on private or distributed networks. In essence, it serves as a “phone book” for translating hostnames into IP addresses. In 1984, the first UNIX implementation referred to as BIND was created by four Berkeley students; David Riggle, Mark Painter, Douglas Terry, and Songnian Zhou. BIND would be refined and maintained since then and was later ported to Windows NT in the early 1990s. Today, DNS makes it possible for naming conventions to remain consistent despite changing in routing configurations or arrangements.
ARPANET would be connected to the Norwegian Seismic Array, or NORSAR, in 1973 making Norway the first country outside of the United States to connect to the network. Soon after, a London IMP was added and in 1975 ARPANET was declared operational. When this occurred, the Defense Communications Agency took control of the network. Then, in 1983 ARPANET was split between MILNET (for military use) and civilian use. Gateways were used to relay email between the two networks and MILNET would later become the NIPRNet that is still used today. On February 28th, 1990, ARPANET would be formally decommissioned.
The Impact of HTML
Like many of the great inventions we enjoy today, HTML was developed by Tim Berners-Lee while working in the computer services section of CERN out of the need to collaborate amongst other particle physics researchers. In 1989, he had the idea of trying to enable researchers located at remote sites in the world by allowing them to pool and organize information by linking the text in the files together. Berners-Lee had previously worked on document production and text processing before arriving at CERN having produced the hypertext system, “Enquire,” in 1980 for his personal use. He would then produce a prototype Web browser on the NeXT computer in 1990.
The HTML markup invented by Berners-Lee had a significant grounding in SGML (Standard Generalized Mark-Up), that was an internationally agreed upon method for marking text up into structural units (paragraphs, headings, lists, etc.). The primary idea of using a markup was that the language was independent of the formatter. HTML like SGML made use of pair tags such as the opening and closing tags: <TITLE> </TITLE>. Other elements of SGML that he used were the paragraph, heading, and both ordered and unordered lists amongst others. SGML did not include hypertext links with anchor elements which were purely Berners-Lee’s invention along with the www.sitename.name syntax for addressing sites on the Internet. By basing HTML on SGML which was already widely accepted, HTML was able to gain acceptance by the remainder of what would become the Internet community. He would then introduce the World Wide Web to the public on August 6th, 1991 and release HTML for public use.
The Turning Point for the Internet
A significant turning point for the widespread adoption of the Internet or World Wide Web came with the release of the Mosaic web browser in 1993. Mosaic was a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA-UIUC). The funding for development of the browser came from the High Performance Computing Act of 1991 which is also known as the “Gore Bill.” Although Gore’s claims regarding his role in the “invention” of the Internet have been light a fair bit across the open press, he is credited with coining the term the “Information Superhighway.” Mosaic would later be superseded by Netscape Navigator in 1994 which would hold the title as the world’s most popular web browser for a number of years until supplanted by Microsoft’s Internet Explorer.