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ARPANET – 1969 |
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Network of military and research installations |
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BITnet (Because Its Time) – 1980 |
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Network for mostly Eastern universities |
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ARPANET becomes Internet – 1990 |
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Bitnet and other network users move over to
Internet |
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Packet switching v circuit switching |
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Distributed resources v Star topology |
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Backbones |
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MCI Worldcom |
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GTE |
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Sprint |
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Internet Service Providers (ISP) |
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Domain Name System (DNS) |
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Legal aspects |
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Technical aspects |
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Top-level or zone (.com, .mil, .edu) |
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Vaxa.oshkosh.edu (US assumed) |
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Namibian.com.na |
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Message broken into packets |
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Packets sent independently |
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Packets reassembled and reordered at receiving
machine |
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Each router forwards message using optimal path
(determined by hop count, proximity, queue length, and priority). |
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Encapsulated packet begins with these fields: |
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IP Version ( 4 bits, currently v4) |
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Header length (4 bits, normally 20 bytes) |
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Priority level (7 bits) |
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Packet length (16 bits – 65,535 byte max) |
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Packet ID # (16 bits) |
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Flag (3 bits – last or more fragments) |
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Fragment offset (12 bits – used in packet
reassembly) |
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Time to Live (8 bit – hop count) |
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Protocol of next layer (8 bits) |
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Parity check (16 bits) |
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Source address (32 bits) |
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Destination address (32 bits) |
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(32 bits can encode an address no larger than
4,294,967,296 or 2**32) |
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E-mail and listservs |
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Remote log-in – Telnet |
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Information Retrieval |
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FTP File transfer protocol |
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Gopher |
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World Wide Web |
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Tim Berners-Lee (CERN) – 1989 |
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Hypertext linkage of technical documents |
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Marc Andreeson – U of Illinois – |
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Mosaic Browser |
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Later founded Netscape |
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Display name of URLs |
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Translate name to Internet address |
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Request service of server holding document |
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Copy document to local computer |
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Display document |
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Provide public access to company data |
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Advertise products |
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Provide information to business partners |
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Accept orders |
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Support sales (help desk, shipping info) |
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Inform employees (intranet) |
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Notes