who now the history of internet ?

The Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked web pages and other resources of the World Wide Web (WWW). In the 1950s and early 1960s, prior to the widespread inter-networking that led to the Internet, most communication networks were limited by their nature to only allow communications between the stations on the network. Some networks had gateways or bridges between them, but these bridges were often limited or built specifically for a single use. One prevalent computer networking method was based on the central mainframe method, simply allowing its terminals to be connected via long leased lines. This method was used in the 1950s by Project RAND to support researchers such as Herbert Simon, in Pittsburgh, Pennsylvania, when collaborating across the continent with researchers in Santa Monica, California, on automated theorem proving and artificial intelligence. Advanced Research Projects Agency was renamed to Defense Advanced Research Projects Agency (DARPA) in 1981. A fundamental pioneer in the call for a global network, J.C.R. Licklider, articulated the idea in his January 1960 paper, Man-Computer Symbiosis. "A network of such [computers], connected to one another by wide-band communication lines" which provided "the functions of present-day libraries together with anticipated advances in information storage and retrieval and [other] symbiotic functions. "—J.C.R. Licklider[1] In October 1962, Licklider was appointed head of the United States Department of Defense's DARPA information processing office, and formed an informal group within DARPA to further computer research. As part of the information processing office's role, three network terminals had been installed: one for System Development Corporation in Santa Monica, one for Project Genie at the University of California, Berkeley and one for the Multics project SHOPPING at the Massachusetts Institute of Technology (MIT). Licklider's need for inter-networking would be made evident by the problems this caused. "For each of these three terminals, I had three different sets of user commands. So if I was talking online with someone at S.D.C. and I wanted to talk to someone I knew at Berkeley or M.I.T. about this, I had to get up from the S.D.C. terminal, go over and log into the other terminal and get in touch with them. I said, it's obvious what to do (But I don't want to do it): If you have these three terminals, there ought to be one terminal that goes anywhere you want to go where you have interactive computing. That idea is the ARPAnet." - Robert W. Taylor, co-writer with Licklider of "The Computer as a Communications Device", in an interview with the New York Times[2] Packet Switching Main article: Packet switching At the tip of the inter-networking problem lay the issue of connecting separate physical networks to form one logical network, with much wasted capacity inside the assorted separate network. During the 1960s, Donald Davies (NPL), Paul Baran (RAND Corporation), and Leonard Kleinrock (MIT) developed and implemented packet switching. The notion that the Internet was developed to survive a nuclear attack has its roots in the early theories developed by RAND, but is an urban legend, not supported by any Internet Engineering Task Force or other document. Early networks used for the command and control of nuclear forces were message switched, not packet-switched, although current strategic military networks are, indeed, packet-switching and connectionless. Baran's research had approached packet switching from studies of decentralisation to avoid combat damage compromising the entire network.[3] [edit] Networks that led to the Internet [edit] X.25 and public access Main articles: X.25, Bulletin board system, and FidoNet Following on from ARPA's research, packet switching network standards were developed by the International Telecommunication Union (ITU) in the form of X.25 and related standards. In 1974, X.25 formed the basis for the SERCnet network between British academic and research sites, which later became JANET. The initial ITU Standard on X.25 was approved in March 1976. This standard was based on the concept of virtual circuits. The British Post Office, Western Union International and Tymnet collaborated to create the first international packet switched network, referred to as the International Packet Switched Service (IPSS), in 1978. This network grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981. By the 1990s it provided a worldwide networking infrastructure.[4] Unlike ARPAnet, X.25 was also commonly available for business use. Telenet offered its Telemail electronic mail service, but this was oriented to enterprise use rather than the general email of ARPANET. The first dial-in public networks used asynchronous TTY terminal protocols to reach a concentrator operated by the public network. Some public networks, such as CompuServe used X.25 to multiplex the terminal sessions into their packet-switched backbones, while others, such as Tymnet, used proprietary protocols. In 1979, CompuServe became the first service to offer electronic mail capabilities and technical support to personal computer users. The company broke new ground again in 1980 as the first to offer real-time chat with its CB Simulator. There were also the America Online (AOL) and Prodigy dial in networks and many bulletin board system (BBS) networks such as FidoNet. FidoNet in particular was popular amongst hobbyist computer users, many of them hackers and amateur radio operators. [edit] UUCP Main articles: UUCP and Usenet In 1979, two students at Duke University, Tom Truscott and Jim Ellis, came up with the idea of using simple Bourne shell scripts to transfer news and messages on a serial line with nearby University of North Carolina at Chapel Hill. Following public release of the software, the mesh of UUCP hosts forwarding on the Usenet news rapidly expanded. UUCPnet, as it would later be named, also created gateways and links between FidoNet and dial-up BBS hosts. UUCP networks spread quickly due to the lower costs involved, and ability to use existing leased lines, X.25 links or even ARPANET connections. By 1981 the number of UUCP hosts had grown to 550, nearly doubling to 940 in 1984. [edit] Merging the networks and creating the Internet [edit] TCP/IP Main article: Internet protocol suite Map of the TCP/IP test network in January 1982 Map of the TCP/IP test network in January 1982 With so many different network methods, something was needed to unify them. Robert E. Kahn of DARPA and ARPANET recruited Vint Cerf of Stanford University to work with him on the problem. By 1973, they had soon worked out a fundamental reformulation, where the differences between network protocols were hidden by using a common internetwork protocol, and instead of the network being responsible for reliability, as in the ARPANET, the hosts became responsible. Cerf credits Hubert Zimmerman, Gerard LeLann and Louis Pouzin (designer of the CYCLADES network) with important work on this design.[5] At this time, the earliest known use of the term Internet was by Vinton Cerf, who wrote: “ Specification of Internet Transmission Control Program. ” "Request for Comments No. 675" (Network Working Group, electronic text (1974) [6] With the role of the network reduced to the bare minimum, it became possible to join almost any networks together, no matter what their characteristics were, thereby solving Kahn's initial problem. DARPA agreed to fund development of prototype software, and after several years of work, the first somewhat crude demonstration of a gateway between the Packet Radio network in the SF Bay area and the ARPANET was conducted. On November 22, 1977[7] a three network demonstration was conducted including the ARPANET, the Packet Radio Network and the Atlantic Packet Satellite network—all sponsored by DARPA. Stemming from the first specifications of TCP in 1974, TCP/IP emerged in mid-late 1978 in nearly final form. By 1981, the associated standards were published as RFCs 791, 792 and 793 and adopted for use. DARPA sponsored or encouraged the development of TCP/IP implementations for many operating systems and then scheduled a migration of all hosts on all of its packet networks to TCP/IP. On 1 January 1983, TCP/IP protocols became the only approved protocol on the ARPANET, replacing the earlier NCP protocol.[8] [edit] ARPANET to Several Federal Wide Area Networks: MILNET, NSI, and NSFNet Main articles: ARPANET and NSFNet After the ARPANET had been up and running for several years, ARPA looked for another agency to hand off the network to; ARPA's primary mission was funding cutting edge research and development, not running a communications utility. Eventually, in July 1975, the network had been turned over to the Defense Communications Agency, also part of the Department of Defense. In 1983, the U.S. military portion of the ARPANET was broken off as a separate network, the MILNET. MILNET subsequently became the unclassified but military-only NIPRNET, in parallel with the SECRET-level SIPRNET and JWICS for TOP SECRET and above. NIPRNET does have controlled security gateways to the public Internet. The networks based around the ARPANET were government funded and therefore restricted to noncommercial uses such as research; unrelated commercial use was strictly forbidden. This initially restricted connections to military sites and universities. During the 1980s, the c