A computer network is a digital telecommunications network which allows nodes to share resources. In computer networks, computing devices exchange data with each other using connections between nodes; these data links are established over cable media such as wires or optic cables, or wireless media such as Wi-Fi. Network computer devices that originate and terminate the data are called network nodes. Nodes are identified by network addresses, can include hosts such as personal computers and servers, as well as networking hardware such as routers and switches. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other. In most cases, application-specific communications protocols are layered over other more general communications protocols; this formidable collection of information technology requires skilled network management to keep it all running reliably. Computer networks support an enormous number of applications and services such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers and fax machines, use of email and instant messaging applications as well as many others.
Computer networks differ in the transmission medium used to carry their signals, communications protocols to organize network traffic, the network's size, traffic control mechanism and organizational intent. The best-known computer network is the Internet; the chronology of significant computer-network developments includes: In the late 1950s, early networks of computers included the U. S. military radar system Semi-Automatic Ground Environment. In 1959, Anatolii Ivanovich Kitov proposed to the Central Committee of the Communist Party of the Soviet Union a detailed plan for the re-organisation of the control of the Soviet armed forces and of the Soviet economy on the basis of a network of computing centres, the OGAS. In 1960, the commercial airline reservation system semi-automatic business research environment went online with two connected mainframes. In 1963, J. C. R. Licklider sent a memorandum to office colleagues discussing the concept of the "Intergalactic Computer Network", a computer network intended to allow general communications among computer users.
In 1964, researchers at Dartmouth College developed the Dartmouth Time Sharing System for distributed users of large computer systems. The same year, at Massachusetts Institute of Technology, a research group supported by General Electric and Bell Labs used a computer to route and manage telephone connections. Throughout the 1960s, Paul Baran and Donald Davies independently developed the concept of packet switching to transfer information between computers over a network. Davies pioneered the implementation of the concept with the NPL network, a local area network at the National Physical Laboratory using a line speed of 768 kbit/s. In 1965, Western Electric introduced the first used telephone switch that implemented true computer control. In 1966, Thomas Marill and Lawrence G. Roberts published a paper on an experimental wide area network for computer time sharing. In 1969, the first four nodes of the ARPANET were connected using 50 kbit/s circuits between the University of California at Los Angeles, the Stanford Research Institute, the University of California at Santa Barbara, the University of Utah.
Leonard Kleinrock carried out theoretical work to model the performance of packet-switched networks, which underpinned the development of the ARPANET. His theoretical work on hierarchical routing in the late 1970s with student Farouk Kamoun remains critical to the operation of the Internet today. In 1972, commercial services using X.25 were deployed, used as an underlying infrastructure for expanding TCP/IP networks. In 1973, the French CYCLADES network was the first to make the hosts responsible for the reliable delivery of data, rather than this being a centralized service of the network itself. In 1973, Robert Metcalfe wrote a formal memo at Xerox PARC describing Ethernet, a networking system, based on the Aloha network, developed in the 1960s by Norman Abramson and colleagues at the University of Hawaii. In July 1976, Robert Metcalfe and David Boggs published their paper "Ethernet: Distributed Packet Switching for Local Computer Networks" and collaborated on several patents received in 1977 and 1978.
In 1979, Robert Metcalfe pursued making Ethernet an open standard. In 1976, John Murphy of Datapoint Corporation created ARCNET, a token-passing network first used to share storage devices. In 1995, the transmission speed capacity for Ethernet increased from 10 Mbit/s to 100 Mbit/s. By 1998, Ethernet supported transmission speeds of a Gigabit. Subsequently, higher speeds of up to 400 Gbit/s were added; the ability of Ethernet to scale is a contributing factor to its continued use. Computer networking may be considered a branch of electrical engineering, electronics engineering, telecommunications, computer science, information technology or computer engineering, since it relies upon the theoretical and practical application of the related disciplines. A computer network facilitates interpersonal communications allowing users to communicate efficiently and via various means: email, instant messaging, online chat, video telephone calls, video conferencing. A network allows sharing of computing resources.
Users may access and use resources provided by devices on the network, such as printing a document on a shared network printer or use of a shared storage device. A network allows sharing of files, and
National research and education network
A National Research and Education Network is a specialised internet service provider dedicated to supporting the needs of the research and education communities within a country. It is distinguished by support for a high-speed backbone network offering dedicated channels for individual research projects. In recent years NRENs have developed many'above the net' services. National Identity federations, many of which are represented in REFEDs, are one example of such services. UbuntuNet Alliance for Research and Education Networking - the Alliance of NRENs of East and Southern Africa Eb@le - DRC NREN EthERNet - Ethiopian NREN iRENALA - Malagasy NREN KENET - Kenyan NREN MAREN - Malawian NREN MoRENet - Mozambican NREN RENU - Ugandan NREN RwEdNet - Rwanda NREN SomaliREN - Somali NREN SudREN - Sudanese NREN TENET/SANReN - South African NREN TERNET - Tanzanian NREN Xnet - Namibian NREN ZAMREN - Zambian NREN TUREN - Tunisian NREN MARWAN - Moroccan NREN ENREN - Egyptian NREN ARN - Algerian NREN SudREN - Sudanese NREN SomaliREN - Somali NREN WACREN - West and Central African Research and Education Network GARNET - Ghanaian NREN GhREN - Ghanaian NREN MaliREN - Mali NREN Niger-REN - Nigerien NREN RITER - Côte d'Ivoire NREN SnRER - Senegalese NREN NgREN - Nigerian NREN AfgREN - Afghanistan NREN BDREN - Bangladeshi NREN ERNET - Indian NREN NKN - Indian NREN NREN - Nepal NREN PERN - Pakistani NREN LEARN - Sri Lankan NREN APAN - Asia-Pacific Advanced Network AARNet - Australian NREN AfgREN - Afghanistan NREN CSTNET - China Science and Technology Network CERNET - China Education and Research Network HARNET - Hong Kong NREN KOREN - Korean NREN KREONET- Korean NREN IDREN - Indonesian NREN SINET - Japanese NREN MYREN - Malaysian NREN NREN - Islamic Republic of Iran NREN REANNZ - New Zealand NREN PREGINET - Philippine NREN SingAREN - Singaporean NREN TWAREN - Taiwanese NREN UniNet - Thai NREN VinaRen - Vietnamese NREN CamREN- Cambodia NREN TEIN - Trans Eurasia Information Network United States – although advocated since the 1980s, the U.
S. does not have one single NREN. Canada RedCLARA - Cooperación Latino Americana de Redes Avanzadas Innova-Red - Argentinian NREN ADSIB - Bolivian NREN RNP - Brazilian NREN REUNA - Chilean NREN RENATA - Colombian NREN RedCONARE - Costa Rican NREN CEDIA - Ecuadorian NREN RAICES - El Salvadoran NREN RAGIE - Guatemalan NREN Universidad Tecnológica Centroamericana - Honduran NREN CUDI - Mexican NREN RENIA - Nicaraguan NREN RedCyT - Panamanian NREN Arandu - Paraguayan NREN RAAP - Peruvian NREN RAU - Uruguayan NREN REACCIUN CNTI?- Venezuelan NREN C@ribNET - Caribbean NREN TTRENT - Trinidad and Tobago NREN JREN - Jamaica NREN RADEI - NREN of the Dominican Republic European Academic and Research Network GÉANT - Develops and maintains the GÉANT backbone network on behalf of European NRENs. DANTE and TERENA. CEENet - Central and Eastern European Research Networking Association Eumedconnect - South Mediterranean Backbone ANA Albanian NREN ASNET-AM - Armenian NREN ACOnet - Austrian NREN AzScienceNet Azerbaijan NREN BASNET - Belarus NREN Belnet - Belgian NREN BREN - Bulgarian NREN CESNET - Czech NREN CARNet - Croatian NREN CYNET - Cypriot NREN SURFnet - Dutch NREN EENet - Estonian NREN RENATER - French NREN Deutsches Forschungsnetz - German NREN GRENA - Georgian NREN GRNET - Greek NREN NIIF/HUNGARNET - Hungarian NREN HEAnet - Irish NREN GARR - Italian NREN KazRENA - Kazakhstan NREN SigmaNet - Latvian NREN LITNET - Lithuanian NREN RESTENA - Luxembourg NREN MARNET - Macedonian NREN RiċerkaNet - Maltese NREN RENAM - Moldovian NREN MREN - Montenegro NREN PIONIER - Polish NREN FCCN - Portuguese NREN RoEduNet - Romanian NREN RUNNet - Russian NREN AMRES - Serbian NREN ARNES - Slovenian NREN SANET - Slovakian NREN RedIRIS - Spanish NREN SWITCH - Swiss NREN ULAKBIM - Turkish NREN URAN - Ukrainian NREN Janet - United Kingdom NREN NORDUnet - Nordic backbone network DeiC - Danish NREN FUNET - Finnish NREN RHnet - Icelandic NREN SUNET - Swedish NREN UNINETT - Norwegian NREN Maeen Saudi Arabia NREN Eumedconnect - Mediterranean/North African Backbone ANKABUT UAE NREN OMREN Omani NREN IUCC - Israeli NREN JUnet Jordanian NREN IRAN SHOA Iranian NREN PALNREN Palestinian NREN Lebanon Birzeit Uni/AlQuds Palestinian Authority QNREN - Qatar NREN HIAST Syrian NREN RUNNet - Russian University Network, Russian NREN ASNET-AM - Armenian AzRENA - Azerbaijan BASNET UNIBEL Belarus GRENA - Georgian NREN KazRENA - Kazakhstan NREN KRENA - Kyrgyzian NREN TuRENA - Turkmenistan NREN UZSCINET - Uzbekistan NREN Information superhighway Overview of Uzbekistan NREN in CEENGINE newsletter Overview of Ukrainian NRENs in CEENGINE newsletter Overview of Albanian NREN in CEENGINE newsletter Overview of Bulgarian NREN in CEENGINE newsletter Signing of Trinidad and Tobago NREN in Trinidad Guardian newspaper Terena Compendium Research and Education Networking FAQ India - High Performance Computing Networks & NRENS.pdf Digital Divide & REN, Case of Bangladesh
France the French Republic, is a country whose territory consists of metropolitan France in Western Europe and several overseas regions and territories. The metropolitan area of France extends from the Mediterranean Sea to the English Channel and the North Sea, from the Rhine to the Atlantic Ocean, it is bordered by Belgium and Germany to the northeast and Italy to the east, Andorra and Spain to the south. The overseas territories include French Guiana in South America and several islands in the Atlantic and Indian oceans; the country's 18 integral regions span a combined area of 643,801 square kilometres and a total population of 67.3 million. France, a sovereign state, is a unitary semi-presidential republic with its capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban areas include Lyon, Toulouse, Bordeaux and Nice. During the Iron Age, what is now metropolitan France was inhabited by a Celtic people. Rome annexed the area in 51 BC, holding it until the arrival of Germanic Franks in 476, who formed the Kingdom of Francia.
The Treaty of Verdun of 843 partitioned Francia into Middle Francia and West Francia. West Francia which became the Kingdom of France in 987 emerged as a major European power in the Late Middle Ages following its victory in the Hundred Years' War. During the Renaissance, French culture flourished and a global colonial empire was established, which by the 20th century would become the second largest in the world; the 16th century was dominated by religious civil wars between Protestants. France became Europe's dominant cultural and military power in the 17th century under Louis XIV. In the late 18th century, the French Revolution overthrew the absolute monarchy, established one of modern history's earliest republics, saw the drafting of the Declaration of the Rights of Man and of the Citizen, which expresses the nation's ideals to this day. In the 19th century, Napoleon established the First French Empire, his subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a tumultuous succession of governments culminating with the establishment of the French Third Republic in 1870.
France was a major participant in World War I, from which it emerged victorious, was one of the Allies in World War II, but came under occupation by the Axis powers in 1940. Following liberation in 1944, a Fourth Republic was established and dissolved in the course of the Algerian War; the Fifth Republic, led by Charles de Gaulle, remains today. Algeria and nearly all the other colonies became independent in the 1960s and retained close economic and military connections with France. France has long been a global centre of art and philosophy, it hosts the world's fourth-largest number of UNESCO World Heritage Sites and is the leading tourist destination, receiving around 83 million foreign visitors annually. France is a developed country with the world's sixth-largest economy by nominal GDP, tenth-largest by purchasing power parity. In terms of aggregate household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, human development.
France is considered a great power in global affairs, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a leading member state of the European Union and the Eurozone, a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, La Francophonie. Applied to the whole Frankish Empire, the name "France" comes from the Latin "Francia", or "country of the Franks". Modern France is still named today "Francia" in Italian and Spanish, "Frankreich" in German and "Frankrijk" in Dutch, all of which have more or less the same historical meaning. There are various theories as to the origin of the name Frank. Following the precedents of Edward Gibbon and Jacob Grimm, the name of the Franks has been linked with the word frank in English, it has been suggested that the meaning of "free" was adopted because, after the conquest of Gaul, only Franks were free of taxation.
Another theory is that it is derived from the Proto-Germanic word frankon, which translates as javelin or lance as the throwing axe of the Franks was known as a francisca. However, it has been determined that these weapons were named because of their use by the Franks, not the other way around; the oldest traces of human life in what is now France date from 1.8 million years ago. Over the ensuing millennia, Humans were confronted by a harsh and variable climate, marked by several glacial eras. Early hominids led a nomadic hunter-gatherer life. France has a large number of decorated caves from the upper Palaeolithic era, including one of the most famous and best preserved, Lascaux. At the end of the last glacial period, the climate became milder. After strong demographic and agricultural development between the 4th and 3rd millennia, metallurgy appeared at the end of the 3rd millennium working gold and bronze, iron. France has numerous megalithic sites from the Neolithic period, including the exceptiona
Internet exchange point
An Internet exchange point is the physical infrastructure through which Internet service providers and content delivery networks exchange Internet traffic between their networks. IXPs reduce the portion of an ISP's traffic that must be delivered via their upstream transit providers, thereby reducing the average per-bit delivery cost of their service. Furthermore, the increased number of paths available through the IXP improves routing efficiency and fault-tolerance. In addition, IXPs exhibit the characteristics of; the primary purpose of an IXP is to allow networks to interconnect directly, via the exchange, rather than through one or more third-party networks. The primary advantages of direct interconnection are cost and bandwidth. Traffic passing through an exchange is not billed by any party, whereas traffic to an ISP's upstream provider is; the direct interconnection located in the same city as both networks, avoids the need for data to travel to other cities to get from one network to another, thus reducing latency.
The third advantage, speed, is most noticeable in areas that have poorly developed long-distance connections. ISPs in these regions might have to pay between 10 or 100 times more for data transport than ISPs in North America, Europe, or Japan. Therefore, these ISPs have slower, more limited connections to the rest of the Internet. However, a connection to a local IXP may allow them to transfer data without limit, without cost, vastly improving the bandwidth between customers of the two adjacent ISPs. A typical IXP consists of one or more network switches, to which each of the participating ISPs connect. Prior to the existence of switches, IXPs employed fiber-optic inter-repeater link hubs or Fiber Distributed Data Interface rings, migrating to Ethernet and FDDI switches as those became available in 1993 and 1994. Asynchronous Transfer Mode switches were used at a few IXPs in the late 1990s, accounting for 4% of the market at their peak, there was an attempt by Stockholm-based IXP NetNod to use SRP/DPT, but Ethernet has prevailed, accounting for more than 95% of all existing Internet exchange switch fabrics.
All Ethernet port speeds are to be found at modern IXPs, ranging from 10 Mb/second ports in use in small developing-country IXPs, to ganged 10 Gb/second ports in major centers like Seoul, New York, Frankfurt and Palo Alto. Ports with 100 Gb/second are available, for example, at the AMS-IX in Amsterdam and at the DE-CIX in Frankfurt. There are five types of business models for IXPs: Nonprofit organization Association of ISPs Operator-neutral for-profit company University or government agency Informal association of networksThe technical and business logistics of traffic exchange between ISPs is governed by mutual peering agreements. Under such agreements, traffic is exchanged without compensation; when an IXP incurs operating costs, they are shared among all of its participants. At the more expensive exchanges, participants pay a monthly or annual fee determined by the speed of the port or ports which they are using. Fees based on volume of traffic are less common because they provide a counterincentive to growth of the exchange.
Some exchanges charge a setup fee to offset the costs of the switch port and any media adaptors that the new participant requires. Internet traffic exchange between two participants on an IXP is facilitated by Border Gateway Protocol routing configurations between them, they choose to announce routes via the peering relationship – either routes to their own addresses, or routes to addresses of other ISPs that they connect to via other mechanisms. The other party to the peering can apply route filtering, where it chooses to accept those routes, route traffic accordingly, or to ignore those routes, use other routes to reach those addresses. In many cases, an ISP will have both a direct link to another ISP and accept a route to the other ISP through the IXP. In this way, the IXP acts as a backup link; when these conditions are met, a contractual structure exists to create a market to purchase network services, the IXP is sometimes called a "transit exchange". The Vancouver Transit Exchange, for example, is described as a "shopping mall" of service providers at one central location, making it easy to switch providers, "as simple as getting a VLAN to a new provider".
The VTE is run by a public entity. Advocates of green broadband schemes and more competitive telecommunications services advocate aggressive expansion of transit exchanges into every municipal area network so that competing service providers can place such equipment as video on demand hosts and PSTN switches to serve existing phone equipment, without being answerable to any monopoly incumbent. Euro-IX, the first association of Internet exchange points, was formed in May 2001; the Internet Exchange Federation, which includes Euro-IX, APIX, LAC-IX, was formed in November 2012. The African Internet Exchange Association joined the Internet Exchange Federation on 7 October 2014. List of Internet exchange points List of Internet exchange points by size Colocation centre Packet Clearing House Route server Historical IXPs Commercial Internet eXchange Federal Internet Exchange Network Access Point European Internet Exch