Packet switching

src: www.allsyllabus.com

Package redirection is a method of grouping data that is transmitted over a digital network into a packet made of header and payload. The data in the header is used by the network hardware to redirect the packet to its destination where the charge is extracted and used by the application software. Packet switching is the main basis for data communications on computer networks around the world.

In the early 1960s, American computer scientist Paul Baran developed the concept of Distributed Adaptive Message Block Switching with the aim of providing a tolerant and efficient routing method for telecommunication messages as part of a research program at RAND Corporation, funded by the US Department of Defense. This concept contrasts with and contradicts the principles of pre-allocation of network bandwidth, largely reinforced by the development of telecommunications in the Bell System. The new concept found little resonance among network implementers to the independent work of British computer scientist Donald Davies at the National Physical Laboratory (United Kingdom) in 1965. Davies is credited with combining the modern name of packet switching and inspiring many packet networks switching in the following decades, including the incorporation of concepts in the early ARPANET in the United States.

Video Packet switching

Drafts

The simple definition of packet redirection is:

Routing and moving data through packets addressed so that a channel is occupied during packet transmission only, and after channel transmission completion is available for other traffic transfers.

Packet switching features a variable data transfer rate bit rate, realized as a packet sequence, through a computer network that allocates the necessary transmission resources using statistical multipleking techniques or dynamic bandwidth allocation techniques. When they traverse network nodes, such as switches and routers, packets are received, buffered, queued, and sent (stored and forwarded), resulting in latency and variable throughput depending on link capacity and traffic load on the network.

Package switching contrasts with other major network paradigms, circuit switching, methods that allocate pre-dedicated network bandwidth specific to each communication session, each having a constant bit rate and latency between nodes. In the case of billable services, such as cellular communication services, circuit switching is characterized by the cost per unit of connection time, even when no data is transferred, while packet switching can be characterized by the cost per unit of information transmitted, such as characters, packets, or messages.

Package mode communication can be implemented with or without an intermediate forwarding node (packet or router switch). Packages are usually forwarded by an asynchronous intermediate network node using first-out, out-first buffers, but can be forwarded according to some scheduling disciplines for reasonable queuing, traffic generation, or for different or guaranteed quality of service, such as fair weighted queues or a leaky bucket. In the case of shared physical media (such as radio or 10BASE5), packets may be sent according to a dual access scheme.

Maps Packet switching

History

In the late 1950s, the US Air Force established a wide area network for the Semi-Automatic Ground Environment (SAGE) radar defense system. They are looking for a system that can withstand nuclear attacks to enable response, thus reducing the attractiveness of the first attack advantage by the enemy.

Leonard Kleinrock conducted preliminary research in queuing theory and published a book in the related field of digital messaging (without packets) in 1961.

The concept of small data block switching was first explored independently by Paul Baran at RAND Corporation beginning in the late 1950s in the US and later by Donald Davies at the National Physical Laboratory (NPL) in the UK.

Baran developed the concept of dissemination of adaptive message block changes during his research at RAND Corporation for the US Air Force into a resilient communication network from nuclear war. First presented to the Air Force in the summer of 1961 as a briefing B-265, later published as RAND P-2626 report in 1962, and finally in the RM 3420 report in 1964. The P-2626 report describes the general architecture for large-scale, communication networks that can survive. This work focuses on three main ideas: the use of decentralized networks with multiple paths between two points, dividing user messages into message blocks , and delivering these messages with store and forward copy.

Donald Davies at the National Physical Laboratory (UK) developed the concept of routing similar messages in 1965. He called it packet switching, a name more accessible than Baran's terminology, and proposed building a national network in England. He gave a lecture on the proposal in 1966, after which someone from the Ministry of Defense (MoNE) informed him of Baran's work. A Davies team member (Roger Scantlebury) meets Lawrence Roberts at the 1967 ACM Symposium on the Principles of Operating Systems and recommends them for use in the ARPANET. Davies has selected some of the same parameters for his original network design as did Baran, such as packet size of 1024 bits. In 1966, Davies proposed that the network should be built in the laboratory to serve NPL needs and prove the feasibility of packet switching. Following a pilot experiment in 1967, the NPL Data Communications Network began operations in 1969.

Building on earlier work on queuing theory, Leonard Kleinrock then did theoretical work to model the performance of packet-switched networks, which support the development of the ARPANET. The NPL team also does the simulation work on the packet network.

In 1974, Vint Cerf and Bob Kahn published a specification for Transmission Control Protocol (TCP), an internetworking protocol for sharing resources using packet-switching between nodes (the monolithic protocol is then coated as TCP above Protocol Internet, or IP ).

The French CYCLADES network, designed by Louis Pouzin in the early 1970s, was the first to make the host responsible for reliable data transmission, rather than this being a centralized service of the network itself.

src: i.ytimg.com

Connectionless and connection-oriented mode

Packet switching can be classified into packet switching without connections, also known as datagram displacement, and packet-oriented connection switching, also known as switching virtual circuits.

Contoh protokol connectionless adalah Ethernet, Internet Protocol (IP), dan User Datagram Protocol (UDP). Protokol berorientasi koneksi termasuk X.25, Frame Relay, Multiprotocol Label Switching (MPLS), dan Transmission Control Protocol (TCP).

In connectionless mode each packet includes complete addressing information. Packages are routed individually, sometimes resulting in different paths and non-custom delivery. Each packet is labeled with the destination address, source address, and port number. It may also be labeled with packet number. This precludes the need for dedicated paths to help packets find their way to their destination, but means more information is needed in packet headers, which are therefore larger, and this information needs to be sought in power-hungry content. Built-in memory. Each packet is sent and can be through a different route; potentially, the system should do a lot of work for each packet as the connection-oriented system should be done in connection settings, but with little information about the application requirements. At the destination, the original message/data is reassembled in the correct order, based on the packet number. So virtual connections, also known as virtual circuits or byte streams are given to the end user by the transport layer protocol, although the intermediate network node only provides network layer services without a connection.

Connection-oriented transmission requires phase setting at each node involved before any packet is transferred to specify communication parameters. The packets include connection identifiers rather than address information and are negotiated between end points so that they are sent in sequence and by error checking. Address information is only transferred to each node during the connection setup phase, when a route to destination is found and entries are added to the switching table in each network node passed by the connection. The signaling protocol used allows the application to determine its requirements and find link parameters. Acceptable values ​​for service parameters are negotiable. Routing a packet requires a node to find the connection id in a table. The packet header can be small, as it only needs to load this code and any information, such as length, timestamp, or different sequence numbers, for different packages.

src: images.wisegeek.com

Service pack switches

Packet switching is used to optimize the use of available channel capacity in digital telecommunication networks, such as computer networks, and minimize transmission latency (the time required for data to pass through the network), and to improve communication robustness.

The most popular use of packet switching is the Internet and most local area networks. The Internet is implemented by the Internet Protocol Suite using various Link Layer technologies. For example, Ethernet and Frame Relay are common. Newer mobile technologies (e.g., GPRS, i-mode) also use packet redirects.

X.25 is an important use of packet switching in that, although based on the packet switching method, it provides virtual circuits to users. This virtual circuit carries a variable-length packet. In 1978, X.25 provided the first international and international packet switching network, International Packet Switched Service (IPSS). Asynchronous Transfer Mode (ATM) is also a virtual circuit technology, which uses a fixed-line fixed-line connection.

The transfer of datagram packets is also called a network without connections because no connection is made. Technologies such as Multiprotocol Label Switching (MPLS) and Resource Reservation Protocol (RSVP) create virtual circuits over a datagram network. Virtual circuits are very useful in building powerful failover mechanisms and allocating bandwidth for time-sensitive applications.

MPLS and its predecessors, as well as ATMs, have been called "fast packet" technology. MPLS, indeed, has been called "ATM without cells". Modern routers, however, do not need this technology to be able to forward variable-length packets at multigigabit speeds across the network.

src: i.ytimg.com

X.25 vs. Frame Relay

X.25 and Frame Relay provide connection-oriented operations. X.25 provides it through the OSI Model network layer, while Frame Relay provides it through a tier two, data link layer. Another major difference between X.25 and Frame Relay is that X.25 requires a handshake between the communicating party before any user packets are transmitted. Frame Relay does not define a handshake like that. X.25 does not define any operations within the packet network. It only operates on the user's network interface (UNI). Thus, the network provider is free to use whatever procedure it wants on the network. X.25 specifies some restricted retransmission procedures at UNI, and its link layer protocol (LAPB) provides conventional HDLC-type linkage management procedures. Frame Relay is a modified version of the two layers of ISDN, LAPD and LAPB protocols. Thus, its integrity operation is only related between the nodes in the links, not the end-to-end. Each retransmission must be performed by a higher layer protocol. The UN.X.25 Protocol is part of the X.25 protocol, which consists of three lower layers of the OSI Model. It was widely used in the UNI for packet switching networks during the 1980s and early 1990s, to provide standard interfaces into and out of packet networks. Some implementations use X.25 in the network as well, but connection-oriented features make these settings complicated and inefficient. Frame relay operates mainly in the two layer of OSI Model. However, the address field (Data Link Connection ID, or DLCI) can be used in the OSI network layer, with a minimum set of procedures. As such, it self rides many X.25 layer 3 sita, but still has DLCI as an ID outside the node-to-node layer of two link protocols. Frame Relay's simplicity makes it faster and more efficient than X.25. Because Frame relay is a data link layer protocol, such as X.25 it does not define internal network routing operations. For X.25 package ID - virtual circuit and virtual channel number must be correlated with network address. The same is true for DLCI Frame Relays. How this is done depends on the network provider. Frame Relay, based on having no connection-oriented network layer procedure on layer two, using HDLC/LAPD/LAPB Set Asynchronous Balanced Mode (SABM). X.25 Connection is usually set for each communication session, but it has a feature that allows a limited amount of traffic to be passed to the entire UNI without a connection-oriented handshake. In the interim, Frame Relay is used to connect LANs across a wide area network. However, X.25 and Frame Relay have been replaced by Internet Protocol (IP) on the network layer, and Asynchronous Transfer Mode (ATM) and/or Multi-Protocol Label Switching (MPLS) version in layer two. Typical configuration is running IP via ATM or MPLS version. & lt; Uyless Black, X.25 and Related Protocols, IEEE Computer Society, 1991 & gt; & lt; Uyless Black, Frame Relay Networks, McGraw-Hill, 1998 & gt; & lt; Uyless Black, MPLS and Label Switching Networks, Prentice Hall, 2001 & gt; & lt; Uyless Black, ATM, Volume I, Prentice Hall, 1995 & gt;

src: blog.umy.ac.id

Packaged-in networks

The history of packet-switched networks can be divided into three overlapping eras: the initial network prior to the introduction of X.25 and the OSI model, X.25 era when many postal, telephone and telegraph companies introduced networks with the X.25 interface, and the Internet era.

Initial network

Research into packet switching at the National Physical Laboratory (NPL) began with a proposal for wide area networks in 1965, and a local area network in 1966. ARPANET funding was secured in 1966 by Bob Taylor and planning began in 1967 when he rented Larry Roberts. The NPL, ARPANET and SITA HLN networks began operations in 1969. Prior to the introduction of X.25 in 1973, about twenty different network technologies have been developed. Two fundamental differences involve the division of functions and tasks between the hosts at the edge of the network and the network core. In a datagram system, the host has a responsibility to ensure regular delivery of the packet. The User Datagram Protocol (UDP) is an example of a datagram protocol. In a virtual calling system, the network guarantees the sending of data that is sorted to the host. This results in a simpler host interface with fewer functions than in the datagram model. Protocol X.25 uses this type of network.

AppleTalk

AppleTalk is an exclusive network protocol suite developed by Apple in 1985 for Apple Macintosh computers. It was the main protocol used by Apple devices through the 1980s and 1990s. AppleTalk includes features that allow local area networks to be set up ad hoc without the requirements for a centralized router or server. The AppleTalk system automatically assigns addresses, updates distributed namespaces, and configures any inter-network routing as needed. It is a plug-n-play system.

The AppleTalk version was also released for IBM PC and compatibles, and Apple IIGS. AppleTalk support is available on most network printers, especially laser printers, multiple file servers and routers. AppleTalk support was discontinued in 2009, replaced by the TCP/IP protocol.

ARPANET

ARPANET is the first Internet progenitor network and network that runs TCP/IP suite using packet switching technology.

BNRNET

BNRNET is a network developed by Bell Northern Research for internal use. Initially only had one host but was designed to support multiple hosts. BNR then made a major contribution to the CCITT X.25 project.

CYCLE

The CYCLADES packet transfer network is a French research network designed and directed by Louis Pouzin. First demonstrated in 1973, it was developed to explore alternatives to the early ARPANET design and to support network research in general. This is the first network that makes the host responsible for reliable data transmission, rather than the network itself, using unreliable datagrams and associated end-to-end protocol mechanisms. This network concept influences the ARPANET architecture later on.

DECnet

DECnet is a network protocol suite created by Digital Equipment Corporation, originally released in 1975 to connect two PDP-11 mini computers. It evolved into one of the first peer-to-peer network architectures, transforming the DEC into a powerhouse network in the 1980s. Originally built with three layers, then (1982) evolved into a corresponding OSI seven-layer network protocol. The DECnet protocol is designed entirely by Digital Equipment Corporation. However, DECnet Phase II (and later) is an open standard with published specifications, and some implementations developed outside the DEC, including one for Linux.

DDX-1

This is an experimental network of Nippon PTT. It switches mixed circuits and packet switching. It was replaced by DDX-2.

EIN nÃÆ' Â © e COST II

The European Informatics Network is a project to connect several national networks. It started operating in 1976.

EPSS

The Experimental Packet Switching System (EPSS) is an experiment of the British Post Office. This was the first public packet transfer network when it began operations in 1977, based on protocols set by the British academic community in 1975. Ferranti supplies hardware and software. Handling link control messages (thank you and flow control) is different from most other networks.

GEIS

As General Electric Information Services (GEIS), General Electric is the premier provider of international information services. The company originally designed the telephone network to serve as an internal voice telephone network (though across the continent).

In 1965, at the urging of Warner Sinback, the voice-based data network was designed to connect four GE sales and service centers (Schenectady, New York, Chicago, and Phoenix) to facilitate computer time-sharing services, apparently the service the world's first commercial online. (In addition to selling GE computers, the centers are computer service bureaus, offering batch processing services.They lost money from the beginning, and Sinback, a high-level marketing manager, was given the task of changing his business.He decided that the time-sharing system, Kemney at Dartmouth - using a computer with a loan from GE - can be profitable Warner is right.)

After becoming an international company a few years later, GEIS created a network data center near Cleveland, Ohio. Very little has been published about their internal network details. (Although it has been stated by some people that Tymshare copied the GEIS system to create their network, Tymnet.) The design is hierarchical with redundant communication links.

IPSANET

IPSANET is a semi-private network built by I. P. Sharp Associates to serve their time-sharing customers. It started operations in May 1976.

IPX/SPX

The Internetwork Packet Exchange (IPX) and Sequenced Packet Exchange (SPX) are Novell network protocols derived from Xerox Network Systems' IDP and SPP protocols, respectively. They are used primarily on networks using the Novell NetWare operating system.

Merit Network

Merit Network, Inc., a 501 (c) (3) independent non-profit corporation administered by Michigan public universities, was formed in 1966 as the Michigan Educational Information Triad of Education to explore computer networks between three Michigan public universities as a means to foster educational development and the state economy. With initial support from the State of Michigan and the National Science Foundation (NSF), the packet-switched network was first demonstrated in December 1971 when an interactive host for host connections was made between IBM's mainframe computer systems at the University of Michigan at Ann Arbor and Wayne State University in Detroit. In October 1972 the connection to the CDC mainframe at Michigan State University in East Lansing completed the triad. Over the next few years in addition to the host to host an enhanced interactive network connection to support the terminal for the host connection, the host for the host batch connection (remote job submission, remote printing, batch file transfers), interactive file transfers, gateways to Tymnet and Telenet's public data network, X.25 host attachments, gateways to the X.25 data network, installed Ethernet hosts, and finally TCP/IP and additional public universities in Michigan join the network. All of this set the stage for Merit's role in the NSFNET project that began in the mid-1980s.

NPL

In 1965, Donald Davies of the National Physical Laboratory (United Kingdom) designed and proposed a national data network based on packet switching. The proposal was not taken nationally but in 1967, a pilot experiment had demonstrated the feasibility of packet switched networks.

In 1969, he began building Mark-switched Mark I network to meet the needs of multidisciplinary laboratories and prove technology in operational conditions. In 1976, 12 computers and 75 terminal devices were installed, and more were added until the network was replaced in 1986. The NPL, followed by the ARPANET, were the first two networks in the world to use packet switching, and were interconnected in the early 1970s..

OCTOPUS

Octopus is a local network at Lawrence Livermore National Laboratory. It connects its dorm in the lab to interactive terminals and various computer peripherals including mass storage systems.

Philips Research

Philips Research Laboratories at Redhill, Surrey developed a packet switching network for internal use. It is a datagram network with a single switching node.

PUP

The PARC Universal Package (PUP or Pup) is one of the earliest two internetwork suite protocols; it was created by researchers at Xerox PARC in the mid-1970s. The entire suite provides routing and packet delivery, as well as higher level functions such as reliable byte streams, along with many applications. Subsequent developments led to Xerox Network Systems (XNS).

RCP

RCP is an experimental network created by PTT France. It is used to gain experience with packet switching technology before the Transpac specification is frozen. RCP is a virtual circuit network different from CYCLADES based on datagrams. RCP emphasizes terminal to host and terminal to terminal connection; CYCLE is related to host-to-host communication. TRANSPAC was introduced as X.25 network. RCP affects the X.25 specification

RETD

Red Especial de Transmissionón de Datos is a network developed by CompaÃÆ' Â ± ÃÆ'a TelefÃÆ'³nica Nacional de EspaÃÆ' Â ± a. It started operations in 1972 and thus was the first public network.

SCANNET

"SCANNET's experimental Nordic packet-switched telecommunication network was implemented in Nordic technical libraries in the 1970s, and it included first of the Nordic Extemplo electronic journals, which was among the first in the university to accommodate microcomputers for general use at the beginning 1980s. "

SITA HLN

SITA is a consortium of airlines. Their High Level Network began operating in 1969 at about the same time as the ARPANET. It brings interactive traffic and message-switching traffic. As with many non-academic networks, very little has been published about it.

IBM System Network Architecture

IBM Systems Network Architecture (SNA) is IBM's network architecture built in 1974. IBM customers can obtain hardware and software from IBM and lease private lines from common carriers to build private networks.

Telenet

Telenet is the first FCC licensed public data network in the United States. It was founded by former ARPA director of IPPA Larry Roberts as a means to make ARPANET technology public. He has tried AT & T's interest in buying technology, but the monopoly reaction is that this is not in line with their future. Bolt, Beranack and Newman (BBN) provide financing. It originally used ARPANET technology but changed the host interface to X.25 and the terminal interface to X.29. Telenet designed these protocols and helped to standardize them in the CCITT. Telenet was founded in 1973 and started its operations in 1975. It became public in 1979 and later sold to GTE.

Tymnet

Tymnet is an international data communications network headquartered in San Jose, CA that uses virtual call packet switched technology and uses the X.25, SNA/SDLC, BSC and ASCII interfaces to connect host computers to thousands of large corporations, educational institutions, and government agencies. Users are usually connected via a dial-up connection or a special asynchronous connection. The business consists of a large public network that supports dial-up users and private network businesses that allow government agencies and large corporations (mostly banks and airlines) to build their own dedicated networks. Private networks are often linked through the gateway to the public network to reach locations not in the private network. Tymnet is also connected with dozens of other public networks in the US and internationally through the X.25/X.75 gateway. (Interesting note: Tymnet was not named after Mr. Tyme. Another employee suggested his name.)

XNS

Xerox Network Systems (XNS) is a Xerox propagated protocol, which provides packet routing and delivery, as well as higher level functions such as reliable streams, and remote procedure calls. It was developed from PARC Universal Packet (PUP).

X.25 era

There are two types of X.25 networks. Some such as DATAPAC and TRANSPAC were initially implemented with X.25 external interfaces. Some older networks such as TELENET and TYMNET have been modified to provide X.25 host interfaces in addition to older host connection schemes. DATAPAC was developed by Bell Northern Research, a joint venture of Bell Canada (general operator) and Northern Telecom (telecom equipment supplier). Northern Telecom sells several DATAPAC clones to foreign PTT including Deutsche Bundespost. X.75 and X.121 allow national X.25 network interconnection. A user or host can call a host on a foreign network by entering the DNIC from a remote network as part of the destination address.

AUSTPAC

AUSTPAC is an Australian public X.25 network operated by Telstra. Started by Telecom Australia in the early 1980s, AUSTPAC is Australia's first public packet-switched data network, supporting applications such as on-line bets, financial applications - the Australian Tax Office utilizes AUSTPAC - and remote terminal access to academic institutions, their connection to AUSTPAC until the mid-1990s in some cases. Access can be through a dial-up terminal to PAD, or, by connecting a permanent X.25 node to the network.

ConnNet

ConnNet is a packet-switched data network operated by Southern New England Telephone Company serving the state of Connecticut.

Datanet 1

Datanet 1 is a public data network operated by PTT Telecom Netherlands (now known as KPN). Datanet 1 expressly refers only to networks and users connected via leased lines (using X.121 DNIC 2041), this name also refers to public service PAD Telepad (using DNIC 2049). And since the main Videotex service uses PAD networks and devices that are modified as infrastructure, the name Datanet 1 is used for this service as well. Although the use of this name is incorrect, all these services are managed by the same person in one KPN department contributing to the confusion.

Datapac

DATAPAC is the first operational X.25 network (1976). It covers major Canadian cities and eventually extends to smaller centers.

Datex-P

Deutsche Bundespost operates this national network in Germany. This technology was obtained from Northern Telecom.

Eirpac

Eirpac is an Irish public data network that supports X.25 and X.28. Launched in 1984, replacing Euronet. Eirpac is run by Eircom.

HIPA-NET

Hitachi designed a private network system for sale as a turnkey package for multi-national organizations. In addition to providing X.25 packets, message redirection software is also included. The message is propped on a node adjacent to the transmitting and receiving terminals. Modified virtual calls are not supported, but through the use of "logical ports", the origin terminal can have a predefined destination terminal menu.

Iberpac

Iberpac is Spain's public packet-switched network, providing X.25 services. Iberpac is run by Telefonica.

JANET

JANET is a British academic and research network, linking all universities, higher education institutions, publicly funded research labs. The X.25 network is based primarily on the GEC 4000 series switch, and runs X.25 to 8 Mbit/s links in its final phase before being converted to an IP-based network. The JANET network grew from the 1970s SRCnet (later called SERCnet) network.

PSS

Packet Switch Stream (PSS) is the British Post Office (later British Telecom) national X.25 network with DNIC 2342. British Telecom renames PSS under the name GNS (Global Network Service), but the name PSS remains better known. PSS also includes public dial-up PAD access, and various InterStream gateways to other services such as Telex.

Transpac

Transpac is the national X.25 network in France. It was developed locally at about the same time as DATAPAC in Canada. The development is done by French PTT and is influenced by experimental RCP network. It began operating in 1978, and served both commercial users and, after Minitel started, consumers.

VENUS-P

VENUS-P is the X.25 international network operating from April 1982 to March 2006. At the peak of its subscription in 1999, VENUS-P connects 207 networks in 87 countries.

Venepaq

Venepaq is the national X.25 public network in Venezuela. It is run by Cantv and allows direct connection and dial up connections. Provide national access at very low cost. It provides national and international access. Venepaq allows connections from 19.2 kbit/s to 64 kbit/s in direct connections, and 1200, 2400 and 9600 bit/s in dial up connections.

Internet Age

When Internet connectivity is available to anyone who can pay for an ISP subscription, the distinction between national networks is blurred. Users no longer see network identifiers like DNIC. Some of the old technologies like circuit switching have reappeared with new names like fast packet switching. Researchers have created several experimental networks to complement the existing Internet.

CSNET

The Computer Science Network (CSNET) is a computer network funded by the US National Science Foundation (NSF) which started operations in 1981. The goal is to extend network benefits, to computer science departments in academic and research institutions that can not connect directly. to ARPANET, due to limited funds or authorization. It plays an important role in spreading awareness, and access to, the national network and is a major milestone on the road to the development of the global Internet.

Internet2

Internet2 is a consortium of not-for-profit United States computer networks led by members of the research and education, industry, and government communities. The Internet community2, in partnership with Qwest, built the first Internet Network2, called Abilene, in 1998 and is a major investor in the National LambdaRail project (NLR). In 2006, Internet2 announced a partnership with Level 3 Communications to launch a new national network, increasing its capacity from 10 Gbit/s to 100 Gbit/s. In October 2007, Internet2 officially retired Abilene and now refers to the new network, higher capacity as the Internet Network2.

NSFNET

The National Science Foundation Network (NSFNET) is a co-ordinated and growing project program sponsored by the National Science Foundation (NSF) beginning in 1985 to promote advanced research and education networks in the United States. NSFNET is also the name given to several national backbone networks operating at speeds of 56 kbit/s, 1.5 Mbit/s (T1), and 45 Mbit/s (T3) built to support NSF network initiatives from 1985-1995. Originally designed to connect researchers with NSF-funded supercomputing centers, through public funding and private industry partnerships developed into a major part of the Internet backbone.

regional network NSFNET

In addition to the five NSF supercomputing centers, NSFNET provides connectivity to eleven regional networks and through this network to many smaller regional networks and campuses in the United States. NSFNET regional networks are:

• BARRNet, Gulf Region Regional Research Network in Palo Alto, California;
• CERFNET, California Education and Research Federation Network in San Diego, California, serving California and Nevada;
• CICNet, the Institutional Networking Organizing Committee through Merit Networks in Ann Arbor, Michigan and later as part of the T3 upgrade through Argonne National Laboratory outside Chicago, serves 10 major universities and the University of Chicago in Illinois, Indiana, Michigan, Minnesota, Ohio , and Wisconsin;
• Merit/MichNet in Ann Arbor, Michigan serving Michigan, formed in 1966, is still operating by 2016;
• MIDNet in Lincoln, Nebraska serving Arkansas, Iowa, Kansas, Missouri, Nebraska, Oklahoma, and South Dakota;
• NEARNET, the New England Academic and Research Network at Cambridge, Massachusetts, was added as part of the upgrade to T3, serving Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont, established in late 1988, operated by BBN contract for MIT, BBN took over responsibility for NEARNET on 1 July 1993;
• NorthWestNet in Seattle, Washington, serves Alaska, Idaho, Montana, North Dakota, Oregon, and Washington, established in 1987;
• NYSERNet, New York Education and Research Network in Ithaca, New York;
• JVNCNet, John von Neumann National Supercomputer Network Center in Princeton, New Jersey, serves Delaware and New Jersey;
• SESQUINET, Sesquicentennial Network in Houston, Texas, was founded on the 150th anniversary of the State of Texas;
• SURAnet, network of the Southeastern University Research Association at College Park, Maryland and later as part of the T3 upgrade in Atlanta, Georgia serving Alabama, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia , and West Virginia, were sold to BBN in 1994; and
• Westnet in Salt Lake City, Utah, and Boulder, Colorado, serves Arizona, Colorado, New Mexico, Utah, and Wyoming.

National LambdaRail

LambdaRail Nasional was launched in September 2003. It is a 12,000-mile high-speed national computer network owned and operated by the US research and education community that runs over fiber-optic lines. This is the first transcontinental 10 Gigabit Ethernet network. It operates with a high aggregate capacity of up to 1.6 Tbit/s and a high 40 Gbit/s bitrate, with plans for 100 Gbit/s. The increase never took place and NLR ceased operations in March 2014.

TransPAC, TransPAC2, and TransPAC3

TransPAC2 and TransPAC3, continued from the TransPAC project, a high-speed international Internet service that connects research and education networks in the Asia-Pacific region to those in the US. TransPAC is part of the NSF International Research Network Connections (IRNC) program.

Very high speed Backbone Network Services (vBNS)

High Speed ​​Backbone Network Services (vBNS) began operations in April 1995 as part of a National Science Foundation (NSF) sponsored project to provide high-speed interconnections between NSF-sponsored supercomputing centers and select access points in the United States. This network is engineered and operated by MCI Telecommunications under a cooperation agreement with the NSF. In 1998, vBNS has grown to connect more than 100 universities and research institutes and techniques through 12 national point of presence with DS-3 (45 Mbit/s), OC-3c (155 Mbit/s), and OC-12c (622 Mbit/s) connect all the OC-12c backbones, a substantial engineering feat for the time being. VBNS installed one of the first IP OC-48c (2.5 Gbit/d) IP links in February 1999 and went on to increase the entire backbone to OC-48c.

In June 1999, MCI WorldCom introduced the vBNS that enabled attachments to the vBNS network by organizations that were not approved by or received support from the NSF. After the expiration of the NSF agreement, vBNS is largely diverted to provide services to the government. Most universities and research centers migrate to the backbone of Internet education2. In January 2006, when MCI and Verizon joined, vBNS became a Verizon Business service.

src: i.ytimg.com

See also

• Switch circuit
• CompuServe
• Message redirection
• Multi-carrier network
• Optic burst shift
• Package radio
• Public data network
• Data networks are publicly redirected
• Save and continue
• Time-Driven Switching - bufferless approach to packet switch
• Transmission delay
• Virtual circuits
• Virtual private network

src: cf.ppt-online.org

References

Bibliography

• Leonard Kleinrock, Information Flow in Large Communication Nets, (MIT, Cambridge, May 31, 1961) Proposal for Ph.D. Thesis
• Leonard Kleinrock. Information Flow in the Large Communications Network (RLE Quarterly Progress Report, July 1961)
• Leonard Kleinrock. Communication Nets: Stochastic Message Flow and Delay (McGraw-Hill, New York, 1964)
• Paul Baran et al., On Distributed Communications, Volume I-XI (RAND Corporate Research Document, August, 1964)
  • Paul Baran, On Distributed Communications: I Introduction to Distributed Communication Networks (RAND Memorandum RM-3420-PR, Aug. 1964)
• Paul Baran, On Distributed Communications Network, (IEEE Transactions on Communications Systems, Vol. CS-12 No. 1, pp. 1-9, March 1964)
• DW Davies, Bartlett RA, RA Scantlebury, and PT Wilkinson, Digital communications network for computers that respond quickly at remote terminals (ACM Symposium on Operating System Principles., October 1967)
• R. A. Scantlebury, P. T. Wilkinson, and K. A. Bartlett, Design of message exchange centers for digital communications networks (IFIP 1968)
• Larry Roberts and Tom Merrill, Toward a Cooperative Computer Network Time-Out (Fall AFIPS Conference October 1966)
• Lawrence Roberts, Packet Switching Evolution (Proceedings of IEEE, November, 1978)

src: i.ytimg.com

Further reading

• Abbate, Janet (2000), Discovering the Internet , MIT Press, ISBNÃ, 9780262511155
• Hafner, Katie Where Witches Are Too Late (Simon and Schuster, 1996) pp. 52-67
• Norberg, Arthur; O'Neill, Judy E. Changing Computer Technology: Information Processing for the Pentagon, 1962-1982 (Johns Hopkins University, 1996)

src: cf.ppt-online.org

External links

• Oral history interview with Paul Baran. Charles Babbage Institute University of Minnesota, Minneapolis. Baran describes his working environment at RAND, as well as his early interest in enduring communication, and the evolution, writing and distribution of his eleven volume work, "On Distributed Communications". Baran discusses his interactions with the group at ARPA responsible for future ARPANET development.
• NPL Video Network NPL Data Communications, 1970s
• History and Design of Package Redirects, sites reviewed by Baran, Roberts, and Kleinrock
• Paul Baran and The Origin of the Internet
• Brief History of the Internet
• "Hobbes' Timeline Internet v8.1", Zakon Robert H'obbes, Zakon Group LLC
• 20 articles about packet redirects in the 1970s
• "Introduction to Changed Network Packages", Phrack , 05/3/88

This article is based on material extracted from the Free Online Computing Dictionary before November 1, 2008 and is incorporated in the "subscription" provision of GFDL, version 1.3 or later.

Source of the article : Wikipedia