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End-to-end Principle
The end-to-end principle is a design principle in computer networking that requires application-specific features (such as reliability and security) to be implemented in the communicating end nodes of the network, instead of in the network itself. Intermediary nodes (such as gateways and routers) that exist to establish the network may still implement these features to improve efficiency but do not guarantee end-to-end functionality. The essence of what would later be called the end-to-end principle was contained in the work of Donald Davies on packet-switched networks in the 1960s. Louis Pouzin Louis Pouzin (born 20 April 1931) is a French computer scientist and Internet pioneer. He directed the development of the CYCLADES computer network in France the early 1970s, which implemented a novel design for packet communication. He was the ... pioneered the use of the end-to-end strategy in the CYCLADES network in the 1970s. The principle was first articulated explicitly in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Network
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or by wireless communication. The devices may be connected in a variety of network topologies. In order to communicate over the network, computers use agreed-on rules, called communication protocols, over whatever medium is used. The computer network can include personal computers, Server (computing), servers, networking hardware, or other specialized or general-purpose Host (network), hosts. They are identified by network addresses and may have hostnames. Hostnames serve as memorable labels for the nodes and are rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marginal Cost
In economics, the marginal cost is the change in the total cost that arises when the quantity produced is increased, i.e. the cost of producing additional quantity. In some contexts, it refers to an increment of one unit of output, and in others it refers to the rate of change of total cost as output is increased by an infinitesimal amount. As Figure 1 shows, the marginal cost is measured in dollars per unit, whereas total cost is in dollars, and the marginal cost is the slope of the total cost, the rate at which it increases with output. Marginal cost is different from average cost, which is the total cost divided by the number of units produced. At each level of production and time period being considered, marginal cost includes all costs that vary with the level of production, whereas costs that do not vary with production are fixed. For example, the marginal cost of producing an automobile will include the costs of labor and parts needed for the additional automobile but not t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Control Protocol (ARPANET)
The Network Control Protocol (NCP) was a communication protocol for a computer network in the 1970s and early 1980s. It provided the transport layer of the protocol stack running on host computers of the ARPANET, the predecessor to the modern Internet. NCP preceded the Transmission Control Protocol (TCP) as a transport layer protocol used during the early ARPANET. NCP was a simplex protocol that utilized two port numbers, establishing two connections for two-way communications. An odd and an even port were reserved for each application layer application or protocol. The standardization of TCP and UDP reduced the need for the use of two simplex ports per application to one duplex port. There is some confusion over the name, even among the engineers who worked with the ARPANET. Originally, there was no need for a name for the protocol stack as a whole, so none existed. When the development of TCP started, a name was required for its predecessor, and the pre-existing acronym 'NCP' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBN Technologies
Raytheon BBN (originally Bolt, Beranek and Newman, Inc.) is an American research and development company based in Cambridge, Massachusetts. In 1966, the Franklin Institute awarded the firm the Frank P. Brown Medal, in 1999 BBN received the IEEE Corporate Innovation Recognition, and on 1 February 2013, BBN was awarded the National Medal of Technology and Innovation, the highest honors that the U.S. government bestows upon scientists, engineers and inventors, by President Barack Obama. It became a wholly owned subsidiary of Raytheon in 2009. History BBN has its roots in an initial partnership formed on 15 October 1948 between Leo Beranek and Richard Bolt, professors at the Massachusetts Institute of Technology. Bolt had won a commission to be an acoustic consultant for the new United Nations permanent headquarters to be built in New York City. Realizing the magnitude of the project at hand, Bolt had pulled in his MIT colleague Beranek for help and the partnership betwee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Request For Quotation
A request for quotation (RfQ) is a business process in which a company or public entity requests a quote from a supplier for the purchase of specific products or services. RfQ generally means the same thing as Call for bids (CfB) and Invitation for bid (IfB). An RfQ typically involves more than the price per item. Information like payment terms, quality level per item or contract length may be requested during the bidding process. To receive correct quotes, RfQs often include the specifications of the items/services to make sure all the suppliers are bidding on the same item/service. Logically, the more detailed the specifications A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard. There are different types of technical or engineering specificati ..., the more accurate the quote will be and comparable to the other suppliers. Another reason for ... [...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] |
TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP). Early versions of this networking model were known as the Department of Defense (DoD) model because the research and development were funded by the United States Department of Defense through DARPA. The Internet protocol suite provides end-to-end data communication specifying how data should be packetized, addressed, transmitted, routed, and received. This functionality is organized into four abstraction layers, which classify all related protocols according to each protocol's scope of networking. An implementation of the layers for a particular application forms a protocol stack. From lowest to highest, the layers are the li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (network)
A network host is a computer or other device connected to a computer network. A host may work as a server offering information resources, services, and applications to users or other hosts on the network. Hosts are assigned at least one network address. A computer participating in networks that use the Internet protocol suite may also be called an IP host. Specifically, computers participating in the Internet are called Internet hosts. Internet hosts and other IP hosts have one or more IP addresses assigned to their network interfaces. The addresses are configured either manually by an administrator, automatically at startup by means of the Dynamic Host Configuration Protocol (DHCP), or by stateless address autoconfiguration methods. Network hosts that participate in applications that use the client–server model of computing are classified as server or client systems. Network hosts may also function as nodes in peer-to-peer applications, in which all nodes share and consum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routledge
Routledge ( ) is a British multinational corporation, multinational publisher. It was founded in 1836 by George Routledge, and specialises in providing academic books, academic journals, journals and online resources in the fields of the humanities, behavioral science, behavioural science, education, law, and social science. The company publishes approximately 1,800 journals and 5,000 new books each year and their backlist encompasses over 140,000 titles. Routledge is claimed to be the largest global academic publisher within humanities and social sciences. In 1998, Routledge became a subdivision and Imprint (trade name), imprint of its former rival, Taylor & Francis, Taylor & Francis Group (T&F), as a result of a £90-million acquisition deal from Cinven, a venture capital group which had purchased it two years previously for £25 million. Following the merger of Informa and T&F in 2004, Routledge became a publishing unit and major imprint within the Informa "academic publishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datagram
A datagram is a basic transfer unit associated with a packet-switched network. Datagrams are typically structured in header and payload sections. Datagrams provide a connectionless communication service across a packet-switched network. The delivery, arrival time, and order of arrival of datagrams need not be guaranteed by the network. History In the early 1970s, the term ''datagram'' was created by combining the words ''data'' and ''telegram'' by the CCITT rapporteur on packet switching, Halvor Bothner-By. While the word was new, the concept had already a long history. In 1964, Paul Baran described, in a RAND Corporation report, a hypothetical military network having to resist a nuclear attack. Small standardized ''message blocks'', bearing source and destination addresses, were stored and forwarded in computer nodes of a highly redundant meshed computer network. Baran wrote: "The network user who has called up a ''virtual connection'' to an end station and has trans ... [...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] |
Paul Baran
Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the dominant basis for data communications in computer networks worldwide, and went on to start several companies and develop other technologies that are an essential part of modern Data communication, digital communication. Early life He was born in Grodno (then in the Second Polish Republic, and since 1945 part of Belarus) on April 29, 1926. He was the youngest of three children in his Lithuanian Jews, Lithuanian Jewish family, with the Yiddish given name "Pesach". His family moved to the United States on May 11, 1928, settling in Boston and later in Philadelphia, where his father, Morris "Moshe" Baran (1884–1979), opened a grocery store. He graduated from Drexel University (then called Drexel Institute of Technology) in 1949, with a degree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
