Difference between revisions of "ARPANET"

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("ARPANET" is _always_ used with the definite article ("the"))
 
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The '''ARPANET''' was the first [[packet]]-based [[wide-area network]]; so called because it was initiated, and initially funded, by ARPA.
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The '''ARPANET''' (the word 'ARPANET' IS '''''always''''' used with the definite article ('the') - using naked 'ARPANET' will reveal that you are a clueless, un-educated 'noob') was the first [[packet]]-based [[wide-area network]]; so named because it was initiated, and initially funded, by [[Defense Advanced Research Projects Agency|ARPA]].
  
It consisted of [[minicomputer]]s called [[Interface Message Processor]]s ('IMPs', for short) running specialized [[packet switch]]ing [[program|code]], joined together with [[synchronous serial line]]s; [[host]] computers were connected to the IMPs by special bit-serial [[interface]]s (see below).
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It was intermediate between a [[circuit-switching|virtual circuit]] network and a [[datagram]] network, but closer to the former. There was no 'call setup'; but it had what amounted to [[connection]]s inside the network, data was delivered reliably and in order, and it had [[flow control]] in the network.
  
Later on, customized IMP variants called [[Terminal Interface Processor]]s ('TIPs', for short) were added to the ARPANET; these provided groups of [[serial lines]] to which could be attached [[terminal]]s, which allowed users at the terminals access to the hosts attached to the ARPANET.
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It consisted of [[minicomputer]]s called [[Interface Message Processor]]s ('IMPs', for short) running specialized [[packet switch]]ing [[program|code]], joined together with [[synchronous serial line]]s; [[host]] computers were initially connected to the IMPs by special bit-serial [[1822 interface]]s.
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(The 1822 'Local Host' and 'Distant Host' interface variants had maximum lengths of about 100 feet and 2,000 feet respectively; to allow connection of hosts at much greater distances, a wholly new interface, the 'Very Distant Host', was eventually added. It used a synchronous seral line, at the hardware level; on the IMP end, the existing serial line [[device controller|interface]]s were used.)
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Later on, customized IMP variants called [[Terminal Interface Processor]]s ('TIPs', for short) were added to the ARPANET; these provided groups of [[asynchronous serial line]]s to which could be attached [[terminal]]s, which allowed users at the terminals access to the hosts attached to the ARPANET.
  
 
==Protocols==
 
==Protocols==
  
The [[protocol family]] used on the early ARPANET included:
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The [[protocol suite]] used on the early ARPANET included:
  
* The [[Host-to-IMP Protocol]], the bottom layer; specified in [http://www.bitsavers.org/pdf/bbn/imp/BBN1822_Jan1976.pdf BBN Report #1822] (multiple editions over time)
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* The [[Host-to-IMP Protocol]], the bottom layer; specified in BBN Report #1822 (below; multiple editions over time)
 
* [http://www.rfc-editor.org/rfc/rfc165.txt ICP], Initial connection protocol
 
* [http://www.rfc-editor.org/rfc/rfc165.txt ICP], Initial connection protocol
* [http://www.cbi.umn.edu/hostedpublications/pdf/McKenzieNCP1972.pdf Host-to-Host Protocol] (early version [http://www.rfc-editor.org/rfc/rfc714.txt here])
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* [https://drive.google.com/file/d/1vBXEHEClcD9XLqueVyVf831LOlqn0hrJ/view Host-to-Host Protocol] (early version [http://www.rfc-editor.org/rfc/rfc714.txt here])
  
These two latter protocols formed the [[Network Control Program]], which all the [[application]] [[protocol]]s ran over.
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These [[protocol]]s formed the [[Network Control Protocol]], which all the [[application]] [[protocol]]s ran over.
  
 
Those included:
 
Those included:
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* [[Port Expander]]
 
* [[Port Expander]]
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* [[Host table]]
  
 
==Further reading==
 
==Further reading==
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* J.M. McQuillan, W.R. Crowther, B.P. Cosell, D.C. Walden, and F.E. Heart, "[http://walden-family.com/impcode/1972-improvements-paper.pdf Improvements in the Design and Performance of the ARPA Network]", Proceedings AFIPS, 1972 FJCC, Vol. 40, pp. 741-754.
 
* J.M. McQuillan, W.R. Crowther, B.P. Cosell, D.C. Walden, and F.E. Heart, "[http://walden-family.com/impcode/1972-improvements-paper.pdf Improvements in the Design and Performance of the ARPA Network]", Proceedings AFIPS, 1972 FJCC, Vol. 40, pp. 741-754.
 
* John M. McQuillan, David C. Walden, "[http://www.walden-family.com/public/whole-paper.pdf The ARPA Network Design Decisions]", in "Computer Networks", Vol. 1, No. 5, August 1977, pp. 243-289.
 
* John M. McQuillan, David C. Walden, "[http://www.walden-family.com/public/whole-paper.pdf The ARPA Network Design Decisions]", in "Computer Networks", Vol. 1, No. 5, August 1977, pp. 243-289.
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* Katie Hafner, "Where Wizards Stay Up Late: The Origins Of The Internet", Simon & Schuster, New York, 1996 - well researched, and accessibly told, history
  
 
==External links==
 
==External links==
  
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* BBN Report #1822, [http://www.bitsavers.org/pdf/bbn/imp/BBN1822_Jan1976.pdf Specification for the Interconnection of a Host and an IMP] - Appendix F contains the VDH specification
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* [https://walden-family.com/bbn/arpanet-rfq.pdf ARPANET RFQ] - the acorn
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* [https://walden-family.com/bbn/arpanet-prop-ocr.pdf ARPANET Proposal] - the seedling
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* [https://walden-family.com/bbn/arpanet-completion-report.pdf A History of the ARPANET: The First Decade ] - the tree <!-- https://ipj.dreamhosters.com/wp-content/uploads/2015/07/A-History-of-the-ARPANet.pdf https://apps.dtic.mil/sti/pdfs/ADA115440.pdf -->
 
* [http://www.chiappa.net/~jnc/tech/arpanet.html ARPANET Technical Information]
 
* [http://www.chiappa.net/~jnc/tech/arpanet.html ARPANET Technical Information]
 
** [http://www.chiappa.net/~jnc/tech/arpageo.html ARPANET Technical Information: Geographic Maps]
 
** [http://www.chiappa.net/~jnc/tech/arpageo.html ARPANET Technical Information: Geographic Maps]
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* [https://ban.ai/multics/doc/kirstein-arpanet.pdf Early Experiences with the ARPANET and INTERNET in the UK]
 
* [https://ban.ai/multics/doc/kirstein-arpanet.pdf Early Experiences with the ARPANET and INTERNET in the UK]
  
[[Category: Networking]]
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[[Category: ARPANET]]

Latest revision as of 12:46, 12 August 2024

The ARPANET (the word 'ARPANET' IS always used with the definite article ('the') - using naked 'ARPANET' will reveal that you are a clueless, un-educated 'noob') was the first packet-based wide-area network; so named because it was initiated, and initially funded, by ARPA.

It was intermediate between a virtual circuit network and a datagram network, but closer to the former. There was no 'call setup'; but it had what amounted to connections inside the network, data was delivered reliably and in order, and it had flow control in the network.

It consisted of minicomputers called Interface Message Processors ('IMPs', for short) running specialized packet switching code, joined together with synchronous serial lines; host computers were initially connected to the IMPs by special bit-serial 1822 interfaces.

(The 1822 'Local Host' and 'Distant Host' interface variants had maximum lengths of about 100 feet and 2,000 feet respectively; to allow connection of hosts at much greater distances, a wholly new interface, the 'Very Distant Host', was eventually added. It used a synchronous seral line, at the hardware level; on the IMP end, the existing serial line interfaces were used.)

Later on, customized IMP variants called Terminal Interface Processors ('TIPs', for short) were added to the ARPANET; these provided groups of asynchronous serial lines to which could be attached terminals, which allowed users at the terminals access to the hosts attached to the ARPANET.

Protocols

The protocol suite used on the early ARPANET included:

These protocols formed the Network Control Protocol, which all the application protocols ran over.

Those included:

See also

Further reading

External links