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Internet History CS 4244: Internet Programming Dr. Eli Tilevich US Science and Technology Policy in the Second Half of the 20th Century • Five decades of history: – The lessons of the “Manhattan Project.” – The 50’s: Complacency. – October 4, 1957. • NASA 1958 • (D)ARPA 1958 Major Themes of Technological Progress • The 60’s: Networking (packet switching) • The 70’s: UNIX (Berkeley and AT&T) • The 80’s PC (IBM, Apple, Microsoft) – 1979 3Com – 1979 Novel – 1981 SUN – 1984 CISCO Chapter 1 Introduction A note on the use of these ppt slides: We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) in substantially unaltered form, that you mention their source (after all, we’d like people to use our book!) If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Thanks and enjoy! JFK/KWR All material copyright 1996-2005 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach Featuring the Internet, 3rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004. Internet History 1961-1972: Early packet-switching principles • 1961: Kleinrock - queueing • 1972: theory shows effectiveness of – ARPAnet public demonstration packet-switching – NCP (Network Control Protocol) • 1964: Baran - packetfirst host-host protocol switching in military nets – first e-mail program • 1967: ARPAnet conceived by – ARPAnet has 15 nodes Advanced Research Projects Agency • 1969: first ARPAnet node operational Internet History 1972-1980: Internetworking, new and proprietary • 1970: ALOHAnet satellite nets • • • • • network in Hawaii 1974: Cerf and Kahn architecture for interconnecting networks 1976: Ethernet at Xerox PARC late70’s: proprietary architectures: DECnet, SNA, XNA late 70’s: switching fixed length packets (ATM precursor) 1979: ARPAnet has 200 nodes Cerf and Kahn’s internetworking principles: – minimalism, autonomy - no internal changes required to interconnect networks – best effort service model – stateless routers – decentralized control define today’s Internet architecture Internet History 1980-1990: new protocols, a proliferation of networks • 1983: deployment of TCP/IP • 1982: smtp e-mail protocol defined • 1983: DNS defined for name-to-IP-address translation • 1985: ftp protocol defined • 1988: TCP congestion control • new national networks: Csnet, BITnet, NSFnet, Minitel • 100,000 hosts connected to confederation of networks Internet History 1990, 2000’s: commercialization, the Web, new apps • Early 1990’s: ARPAnet decommissioned • 1991: NSF lifts restrictions on commercial use of NSFnet (decommissioned, 1995) • early 1990s: Web – hypertext [Bush 1945, Nelson 1960’s] – HTML, HTTP: Berners-Lee – 1994: Mosaic, later Netscape – late 1990’s: commercialization of the Web Late 1990’s – 2000’s: • more killer apps: instant messaging, P2P file sharing • network security to forefront • est. 50 million host, 100 million+ users • backbone links running at Gbps Internet From the Networking Perspective Overview What’s the Internet: “nuts and bolts” view • millions of connected computing devices: hosts = end systems • running network apps • communication links router server workstation mobile local ISP – fiber, copper, radio, satellite – transmission rate = bandwidth regional ISP • routers: forward packets (chunks of data) company network “Cool” internet appliances Web-enabled toaster + weather forecaster IP picture frame http://www.ceiva.com/ World’s smallest web server http://www-ccs.cs.umass.edu/~shri/iPic.html Internet phones What’s the Internet: “nuts and bolts” view • protocols control sending, receiving of msgs – e.g., TCP, IP, HTTP, FTP, PPP • Internet: “network of networks” router server mobile local ISP – loosely hierarchical – public Internet versus private intranet regional ISP • Internet standards – RFC: Request for comments – IETF: Internet Engineering Task Force workstation company network What’s the Internet: a service view • communication infrastructure enables distributed applications: – Web, email, games, ecommerce, file sharing • communication services provided to apps: – Connectionless unreliable – connection-oriented reliable A closer look at network structure: • network edge: applications and hosts • network core: – routers – network of networks • access networks, physical media: communication links The network edge: • end systems (hosts): – run application programs – e.g. Web, email – at “edge of network” • client/server model – client host requests, receives service from always-on server – e.g. Web browser/server; email client/server • peer-peer model: – minimal (or no) use of dedicated servers – e.g. Gnutella, KaZaA, Skype Network edge: connection-oriented service Goal: data transfer TCP service [RFC 793] between end systems • reliable, in-order byte• handshaking: setup stream data transfer (prepare for) data transfer – loss: acknowledgements and retransmissions ahead of time – Hello, hello back human • flow control: protocol – set up “state” in two communicating hosts • TCP - Transmission Control Protocol – Internet’s connectionoriented service – sender won’t overwhelm receiver • congestion control: – senders “slow down sending rate” when network congested