History Of Internet

-

History


Professor Leonard Kleinrockwith the first ARPANET Interface Message Processors at UCLA

Research into packet switching started in the early 1960s and packet switched networks such as Mark I at NPL in the UK, ARPANET, CYCLADES, Merit Network, Tymnet, and Telenet, were developed in the late 1960s and early 1970s using a variety of protocols. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks.[citation needed]
The first two nodes of what would become the ARPANET were interconnected between Leonard Kleinrock's Network Measurement Center at the UCLA's School of Engineering and Applied Scienceand Douglas Engelbart's NLS system at SRI International (SRI) in Menlo Park, California, on 29 October 1969. The third site on the ARPANET was the Culler-Fried Interactive Mathematics center at the University of California at Santa Barbara, and the fourth was the University of Utah Graphics Department. In an early sign of future growth, there were already fifteen sites connected to the young ARPANET by the end of 1971. These early years were documented in the 1972 film Computer Networks: The Heralds of Resource Sharing.
Early international collaborations on ARPANET were sparse. For various political reasons, European developers were concerned with developing the X.25 networks. Notable exceptions were the Norwegian Seismic Array (NORSAR) in June 1973, followed in 1973 by Sweden with satellite links to the Tanum Earth Station and Peter T. Kirstein's research group in the UK, initially at the Institute of Computer Science, University of London and later at University College London.[citation needed]

T3 NSFNET Backbone, c. 1992
In December 1974, RFC 675 – Specification of Internet Transmission Control Program, by Vinton Cerf, Yogen Dalal, and Carl Sunshine, used the term internet, as a shorthand forinternetworking; later RFCs repeat this use, so the word started out as an adjective rather than the noun it is today. Access to the ARPANET was expanded in 1981 when theNational Science Foundation (NSF) developed the Computer Science Network (CSNET). In 1982, the Internet Protocol Suite (TCP/IP) was standardized and the concept of a world-wide network of fully interconnected TCP/IP networks called the Internet was introduced.
TCP/IP network access expanded again in 1986 when the National Science Foundation Network (NSFNET) provided access to supercomputer sites in the United States from research and education organizations, first at 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. Commercial Internet service providers (ISPs) began to emerge in the late 1980s and early 1990s. The ARPANET was decommissioned in 1990. The Internet was commercialized in 1995 when NSFNET was decommissioned, removing the last restrictions on the use of the Internet to carry commercial traffic. The Internet started a rapid expansion to Europe and Australia in the mid to late 1980s and to Asia in the late 1980s and early 1990s.

This NeXT Computer was used by Sir Tim Berners-Lee at CERN and became the world's first Web server.
Since the mid-1990s the Internet has had a tremendous impact on culture and commerce, including the rise of near instant communication by email, instant messaging, Voice over Internet Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web with its discussion forums, blogs, social networking, and online shopping sites. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1-Gbit/s, 10-Gbit/s, or more. The Internet continues to grow, driven by ever greater amounts of online information and knowledge, commerce, entertainment andsocial networking.
During the late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary open nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. As of 31 March 2011, the estimated total number of Internet users was 2.095 billion (30.2% of world population). It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication, by 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet.

Comments

Post a Comment

Popular posts from this blog

What Is Melting Points

-
Image
Most organic compounds have melting points below 200 ºC. Some decompose before melting, a few sublime, but a majority undergo repeated melting and crystallization without any change in molecular structure. When a pure crystalline compound is heated, or a liquid cooled, the change in sample temperature with time is roughly uniform. However, if the solid melts, or the liquid freezes, a discontinuity occurs and the temperature of the sample remains constant until the phase change is complete. This behavior is shown in the diagram on the right, with the green segment representing the solid phase, light blue the liquid, and red the temperature invariant liquid/solid equilibrium. For a given compound, this temperature represents its melting point (or freezing point), and is a reproducible constant as long as the external pressure does not change. The length of the horizontal portion depends on the size of the sample, since a quantity of heat proportional to the heat of fusion must be...
Read more

What Is Atomic And Molecular Orbitals

-
Image
A more detailed model of covalent bonding requires a consideration of valence shell atomic orbitals. For second period elements such as carbon, nitrogen and oxygen, these orbitals have been designated 2 s , 2p x , 2p y   & 2p z . The spatial distribution of electrons occupying each of these orbitals is shown in the diagram below.   Very nice displays of orbitals may be found at the following sites: J. Gutow, Univ. Wisconsin Oshkosh R. Spinney, Ohio State  M. Winter, Sheffield University The valence shell electron configuration of carbon is 2 s 2 , 2p x 1 , 2p y 1  & 2p z 0 . If this were the configuration used in covalent bonding, carbon would only be able to form two bonds. In this case, the valence shell would have six electrons- two shy of an octet. However, the tetrahedral structures of methane and carbon tetrachloride demonstrate that carbon can form four equivalent bonds, leading to the desired octet. In order to explain this covalent bonding,...
Read more

Uses OF Alkynes In Nature And Medicine

-
Alkynes in nature and medicine According to Ferdinand Bohlmann, the first naturally occurring acetylenic compound, dehydromatricaria ester, was isolated from an Artemisia  species in 1826 . Polyynes, a subset of this class of natural products, have been isolated from a wide variety of plant species, cultures of higher fungi, bacteria, marine sponges, and corals.  Some acids like  tariric acid  contains an alkyne group. Diynes and triynes, species with the linkage RC ≡ C-C ≡ CR' and RC ≡ C-C ≡ C-C ≡ CR' respectively, occur in certain plants ( Ichthyothere , Chrysanthemum ,  Cicuta ,  Oenanthe  and other members of the  Asteraceae  and  Apiaceae  families).  Some examples are  cicutoxin , oenanthotoxin ,  falcarinol  and  carotatoxin . These compounds are highly bioactive, e.g. as  nematocides .  1-Phenylhepta-1,3,5-triyne is illustrative of a naturally occurring triyne. Alkynes occ...
Read more