Transcript Internet - The American School of Tampico

Internet
8th Grade Technology
January 2006
What is Internet?
• It is a global collection of
networks, both big and small.
• These networks connect together
in many different ways form the
single entity that we know as the
Internet.
• The very name comes from this
idea of INTERconnected
NETworks.
Internet History
• In the late 1960s the American computer scientist Robert E.
Taylor at the Advanced Research Projects Agency (ARPA),
later called the Defense Advanced Research Projects
Agency (DARPA), of the U.S. Department of Defense
began to look for ways to connect the different technologies
of COMPUTER, networks.
• Led by the American networking pioneer Leonard
Kleinrock, DARPA sponsored an experiment in 1969,
based on the packet-switching principles he had
developed, in which computers at the University of
California campuses at Los Angeles and Santa
Barbara, the University of Utah, and Stanford Research
International (a nonprofit scientific research institute)
successfully communicated with each other.
• Thus began ARPANET, the first internetwork, or system
of interconnected networks.
• In 1972, ARPANET was expanded from 4 to 50
networks, connecting universities and research
organizations with specialized military networks.
Internet History
• In the late 1970s, UNIX to UNIX CoPy (UUCP), a
communications network based on the UNIX operating
system, and Users Network (USENET), serving the
academic community and, later, commercial organizations.
More structured networks, such as the Computer Science
Network (CSNET) and Because It's Time (BITNET),
provided nationwide networking to universities and
research centers.
• In the early 1980s ARPANET split into two networks,
ARPANET and Milnet (an unclassified military network),
the two networks were still interconnected. Access to
ARPANET was originally restricted to the military, defense
contractors, and institutions doing defense research.
• By 1986, ARPANET had links to all major universities
and research facilities, and satellite links to several
international locations.
• That year, the National Science Foundation (NSF)
created a network, NSFNET, to connect
SUPERCOMPUTER, sites around the U.S., as well as
research institutes and schools located near the
supercomputers.
Internet History
• NSFNET had entirely replaced ARPANET, which was
officially dismantled in 1990.
• NSFNET became the central network, or backbone,
of the Internet in the U.S.
• In 1991, then U.S. Senator Al Gore proposed
expanding the architecture of NSFNET to form the
National Research and Education Network, the socalled Information Superhighway, which would
include more elementary and high schools and
community colleges.
• The resulting High Performance Computing Act also
allowed business networks to connect to the Internet
for commercial uses, causing an explosion in its
growth.
• NSFNET was discontinued in 1995 and by the end of
1996 large commercial networks had taken over as
the high-speed central networks of the Internet.
Who is the owner of
Internet?
• Nobody owns the Internet, but it
doesn't mean it is not monitored and
maintained in different ways.
• The Internet Society, a non-profit
group established in 1992, oversees
the formation of the policies and
protocols that define how we use and
interact with the Internet.
How Internet works?
How Internet Works?
• TCP/IP
• IP Address
• ISP
• Domain Name
TCP/IP
• Transmission Control Protocol / Internet
Protocol (TCP/IP)
• Protocols are rules or standards, that allow
unlike computers communicate with other
computers on Internet.
• Developed by the American computer
scientists and Internet pioneers Vinton G. Cerf
and Robert E. Kahn at Stanford University.
• In 1974 they were announced as a common,
or open, standard; that is, they are not
proprietary, or exclusive, to any one
manufacturer.
TCP/IP
• It has been the Internet protocol
since 1983.
• When you send information over
the Internet, the TCP/IP prepares
the data to be sent and received.
• The information is configured so
that different networks can
exchanged information with oneanother.
TCP/IP
•
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TCP initiates the transmission of a data file and
connects to the destination address to ensure endto-end transmission.
IP then breaks the file into packets of information-small enough to travel over the network.
Each packet is coded with the data's correct
sequence in the complete file, as well as with the
binary addresses of the sending and receiving
computers.
To maximize transmission speed, TCP/IP permits
each packet to travel independently over many
different networks to the receiving computer.
The flow of packets across the Internet is directed
by computer equipment called routers.
Each router contains software that reads a packet's
IP address, checks the information, and sends the
packet along cables or other media equipment on
the most efficient path to the next router.
TCP/IP
• The packet-switching process is repeated until
the packet reaches its final destination.
• Along the way, packets may pass through
gateways, which are internetworking devices
that translate protocols between unlike networks
and allow TCP/IP packets to pass through any
system on the route.
• After all the packets arrive at the receiving
computer, IP reads the sequence code and
reassembles the data into the order of the
original file.
• TCP controls the transmission by verifying the
sequence and retransmitting a packet if
necessary.
• TCP/IP is invisible to the user, and the entire
send/receive/verify process takes less than a
second to complete.
IP Address
• For the system to work, every location
(machine, router, name server, hosting
account, etc.) on the internet must have
a unique IP address (a set of numbers
like 216.27.61.137 or
11011000.00011011.00111101.1000100
1).
• The IP address function just like street
addresses for the internet.
• These addresses represent the exact
location of a particular site on the
internet, and serve to guide any other
user to that location.
IP Address
• It is impractical to ask people to remember the
number; however, the domain name is
associated with this particular IP address and
is easy to remember.
• When a user types the domain name into a
web browser, the internet Servers (large
computers at the Internet Service Provider
(ISP) of the user) serve as translators.
• The name servers look up the domain name
and resolves it into the IP address which it
refers to.
• The system is designed so that the user does
not even notice that the translation occurs.
Local ISP in Tampico
• Telmex
– Prodigy 33 kbps or more
– Infinitum 256 kbps, 512 kbps or 2
mbps
• Terra
– Premium for unlimited time
– Pre-pago for 750 minutes
• AOL
• Interxcable
Domain Name
• When you use the Web or send an email message, you use a domain name
to do it.
• For example, the Uniform Resource
Locator (URL)
"http://www.howstuffworks.com"
contains the domain name
howstuffworks.com.
• Every time you use a domain name,
you use the Internet's DNS servers to
translate the human-readable domain
name into the machine-readable IP
address.
DNS
• The domain name and its associated IP
address are first listed on the hosting
organizations Domain Name Server
(DNS).
• Then this information is propagated
over the course of a few days until the
domain name is listed in EVERY name
server.
• The way this operates is similar to
having your name and corresponding
phone number listed in every
phonebook in the world.
Most Familiar Domains
• com
• edu
• int
• gov
• mil
• net
• org
commercial organization,
business, or company
educational institution
international organization
nonmilitary government
organization
military organization
network administration
other nonprofit, nonacademic,
nongovernmental organization
Bibliography
• Internet Society. "A Brief History of the
Internet and Related Networks." Internet
Society. 2005.
http://www.isoc.org/internet/history/cerf.shtml
(27 Nov. 2005).
• Rhonda Davila. "History and Development of
the Internet." San Antonio Public Library.
2000.
http://www.sat.lib.tx.us/Displays/itintro.htm (27
Nov. 2005).
• OPB Learning Media. “Timeline." Nerds 2.0.1.
1998.
http://www.pbs.org/opb/nerds2.0.1/timeline/
(27 Nov. 2005).