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Internet Backbone
The Internet backbone is the principal data routes between large, strategically interconnected computer networks and core routers of the Internet. These data routes are hosted by commercial, government, academic and other high-capacity network centers as well as the Internet exchange points and network access points, which exchange Internet traffic internationally. Internet service providers (ISPs) participate in Internet backbone traffic through privately negotiated interconnection agreements, primarily governed by the principle of settlement-free peering. The Internet, and consequently its backbone networks, do not rely on central control or coordinating facilities, nor do they implement any global network policies. The resilience of the Internet results from its principal architectural features, such as the idea of placing as few network state and control functions as possible in the network elements, instead relying on the endpoints of communication to handle most of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Map 1024
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail, internet telephony, streaming media and file sharing. The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching in the 1960s and the design of computer networks for data communication. The set of rules (communication protocols) to enable internetworking on the Internet arose from research and development commissioned in the 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Cable Map Umap
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as ''boats'' rather than ''ships'' regardless of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; blockade running; nuclear deterrence; stealth operations in denied areas when gathering intelligence and doing reconn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCI Communications
MCI Communications Corporation (originally Microwave Communications, Inc.) was an American telecommunications company headquartered in Washington, D.C. that was at one point the second-largest long-distance provider in the United States. MCI was instrumental in legal and regulatory changes that led to the breakup of the Bell System and introduced competition in the U.S. telephone industry. Its MCI Mail, launched in 1983, was one of the first Email services and its MCI.net was an integral part of the Internet backbone. The company was acquired by WorldCom in 1998. History Founding MCI was founded as Microwave Communications, Inc. on October 3, 1963, with John D. Goeken being named the company's first president. The initial business plan was for the company to build a series of microwave radio relay stations between Chicago, Illinois, and St. Louis, Missouri. The relay stations would then be used to interface with limited-range two-way radios used by truckers along U.S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-carrier
The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls. The first version, the Transmission System 1 (T1), was introduced in 1962 in the Bell System, and could transmit up to 24 telephone calls simultaneously over a single transmission line of copper wire. Subsequent specifications carried multiples of the basic T1 (1.544 Mbit/s) data rates, such as T2 (6.312 Mbit/s) with 96 channels, T3 (44.736 Mbit/s) with 672 channels, and others. Although a ''T2'' was defined as part of AT&T's T-carrier system, which defined five levels, T1 through T5, only the T1 and T3 were commonly in use.1999 ad: On the left, in an aisle seat, a man who very much "filled" his airline seat while on the right side of the aisle is a height-challenged man whose shoe toes barely reach the floor Transmission System 1 The T-carrier is a hardware specification for carrying multiple time-division m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Science Foundation Network
The National Science Foundation Network (NSFNET) was a program of coordinated, evolving projects sponsored by the National Science Foundation (NSF) from 1985 to 1995 to promote advanced research and education networking in the United States. The program created several nationwide Backbone network, backbone computer networks in support of these initiatives. It was created to link researchers to the NSF-funded supercomputing centers. Later, with additional public funding and also with private industry partnerships, the network developed into a major part of the Internet backbone. The National Science Foundation permitted only government agencies and universities to use the network until 1989 when the first commercial Internet service provider emerged. By 1991, the NSF removed access restrictions and the commercial ISP business grew rapidly. History Following the deployment of the CSNET, Computer Science Network (CSNET), a network that provided Internet services to academic compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface Message Processor
The Interface Message Processor (IMP) was the packet switching node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of gateways, which are known today as routers. An IMP was a ruggedized Honeywell DDP-516 minicomputer with special-purpose interfaces and software. In later years the IMPs were made from the non-ruggedized Honeywell 316 which could handle two-thirds of the communication traffic at approximately one-half the cost. An IMP requires the connection to a host computer via a special bit- serial interface, defined in '' BBN Report 1822''. The IMP software and the ARPA network communications protocol running on the IMPs was discussed in , the first of a series of standardization documents published by what later became the Internet Engineering Task Force (IETF). History The concept of an interface computer for computer networking was first proposed in 1966 by Donald Davies for the NPL network in England ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University College London
University College London (Trade name, branded as UCL) is a Public university, public research university in London, England. It is a Member institutions of the University of London, member institution of the Federal university, federal University of London, and is the second-largest list of universities in the United Kingdom by enrolment, university in the United Kingdom by total enrolment and the largest by postgraduate enrolment. Established in 1826 as London University (though without university degree-awarding powers) by founders who were inspired by the radical ideas of Jeremy Bentham, UCL was the first university institution to be established in London, and the first in England to be entirely secular and to admit students regardless of their religion. It was also, in 1878, among the first university colleges to admit women alongside men, two years after University College, Bristol, had done so. Intended by its founders to be Third-oldest university in England debate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first computer networks to implement the TCP/IP protocol suite. Both technologies became the technical foundation of the Internet. The ARPANET was established by the Advanced Research Projects Agency (now DARPA) of the United States Department of Defense. Building on the ideas of J. C. R. Licklider, Robert Taylor (computer scientist), Bob Taylor initiated the ARPANET project in 1966 to enable resource sharing between remote computers. Taylor appointed Lawrence Roberts (scientist), Larry Roberts as program manager. Roberts made the key decisions about the request for proposal to build the network. He incorporated Donald Davies' concepts and designs for packet switching, and sought input from Paul Baran on dynamic routing. In 1969, ARPA awarded the contract to build the Interface Message Processors (IMPs) for the network to Bolt Berane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NPL Network
The NPL network, or NPL Data Communications Network, was a local area computer network operated by the National Physical Laboratory (United Kingdom), National Physical Laboratory (NPL) in London that pioneered the concept of packet switching. Based on designs conceived by Donald Davies in 1965, development work began in 1966. Construction began in 1968 and elements of the first version of the network, the Mark I, became operational in early 1969 then fully operational in January 1970. The Mark II version operated from 1973 until 1986. The NPL network was the first computer network to implement packet switching and the first to use high-speed links. Its original design, along with the innovations implemented in the ARPANET and the CYCLADES network, laid down the technical foundations of the modern Internet. Origins In 1965, Donald Davies, who was later appointed to head of the NPL Division of Computer Science, proposed a commercial national data network in the United Kingdom b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Signaling Rate
In telecommunications, data signaling rate (DSR), also known as gross bit rate, is the aggregate rate at which data passes a point in the transmission (telecommunications), transmission data link, path of a data transmission system. Properties # The DSR is usually expressed in bits per second. # The data signal (information theory), signaling rate is given by \sum_^ \frac where ''m'' is the number of parallel channels, ''ni'' is the number of significant conditions of the modulation in the ''i''-th Communication channel, channel, and ''Ti'' is the unit interval (data transmission), unit interval, expressed in seconds, for the ''i''-th channel. # For serial transmission in a single channel, the DSR reduces to (1/''T'')log2''n''; with a two-condition modulation, i. e. ''n'' = 2, the DSR is 1/''T'', according to Hartley's law. # For parallel transmission with equal unit intervals and equal numbers of significant conditions on each channel, the DSR is (''m''/''T'')log2''n''; in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate. There are several different types of repeaters; a telephone repeater is an amplifier in a telephone line, an optical repeater is an optoelectronic circuit that amplifies the light beam in an optical fiber cable; and a radio repeater is a radio receiver and transmitter that retransmits a radio signal. A broadcast relay station is a repeater used in broadcast radio and television. Overview When an information-bearing signal passes through a communication channel, it is progressively degraded due to loss of power. For example, when a telephone call passes through a wire telephone line, some of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
