Transcript Out on the Internet

The Internet
Chapter 18,
Exploring the Digital Domain
In this chapter . . .
You will learn about
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how the Internet evolved from an experimental network
in the 1970s
how your computer can communicate across the world
with other computers over a span of diverse
interconnected networks
how Internet applications are based on client/server
architecture
basic Internet applications: e-mail, ftp, telnet, and HTTP
examining the future for the Internet
A Short History of the Internet
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1964—Paul Baran (RAND Corp.) proposes a
loosely-coupled, robust network
1969—ARPANET formed as a four-node
network (UCLA, SRI, UCSB, and U of Utah-Salt
Lake City)
1974—Kahn and Cerf head TCP/IP project
1980—CSNET added to ARPANET
1986—NSF forms NSFNET
A Short History of the Internet
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1987—NSFNET “backbone” expands the
Internet worldwide
1989—CERN launches WWW project
1990—ARPANET decommissioned
1992—Internet Society formed
1993—NCSA Mosaic GUI for WWW
1995—NSFNET decomissioned
1998—Government funds Internet2
How the Internet Works
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DATAGRAMs are packets of data that also
contain addressing information
TCP/IP define protocols (standards) for how
datagrams are packaged and delivered
IP address is a number that signifies the
address of an Internet host
Domain names are pseudonyms for IP
addresses
Domain name system servers provide user
with IP numbers for URLs, e-mail addresses,
etc.
How the Internet Works
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Gateways and
Routers transmit
datagrams across
the Internet
Client/Server
applications add
functionality to the
Internet
How the Internet Works
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IP (Internet Protocol)
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how datagrams are routed across the network
TCP and UDP
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how messages are delivered
TCP -- guaranteed service (e-mail, HTTP, etc.)
UDP -- normal service (PING, DNS, etc.)
Basic Internet Applications
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ELECTRONIC MAIL
(EMAIL)
asynchronous
communications
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mail client
mail server
Basic Internet Applications
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REMOTE LOGINS (TELNET)—synchronous
2-way communications
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local host
remote host
Basic Internet Applications
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FILE TRANSFER PROTOCOL (FTP)—
exchanging data and programs
between systems
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anonymous ftp
Basic Internet Applications
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HTTP (HyperText Transfer Protocol)
cookies
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ID used for identifying users, transactions,
etc.
Web caching
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client-side
server-side -- proxy servers
Internet2
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consortium of government , industry,
and education
establish network capabilities to support
national research
develop the next generation of Internet
applications
transfer these to worldwide Internet
Internet2
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Abilene
remote
instrumentation and
virtual laboratories
distance learning
digital libraries
Tele-immersion
multicasting