Transcript The Internet

The Internet
How it works, and its history
Compiled and presented by Alex Righolt for the
Topics in this presentation

Who owns the internet?

Technical background

History of the Internet

Future of the internet
•Network models
•Packet switching
•Dynamic Name Servers
•Connecting
Who owns the Internet? -1
One of the greatest things about the
Internet is that nobody really owns it.
It is a global collection of networks, both
big and small.
Who owns the Internet? - 2
These networks connect
together in many
different ways to form
the single entity that we
know as the Internet.
In fact, the very name
comes from this idea of
interconnected
networks.
Network models - 1
In this centralized
model, all
communication
goes via one
central point. If this
point fails, the
whole system
comes to a halt.
Network models - 2
In a decentralized
system, costs can be
saved by using shorter
paths, and some multipath connections can
be made.
Network models - 3
The Internet uses a
distributed network.
The stations or
“nodes” are scattered
all over the world, and
are not owned by one
organization.
Packet switching - 1
The Internet began to evolve when packetswitching networks came into operation in
the 1960s.
When transmitted, data is broken up into
small packets, sent to its destination and
then reassembled.
Packet switching - 2
How it works:
Packet switching - 3
Packet switching - 4
Packet switching - 5
Packet switching - 6
Packet switching - 7
In this way a single message can be sent to
multiple users, via multiple links.
Packets can be compressed for speed and
encrypted for security.
Dynamic Name Servers - 1
The DNS system forms one of the largest
and most active distributed databases on
the planet.
Without DNS, the Internet would shut
down very quickly.
Dynamic Name Servers - 2
All of the machines connected on the
internet use names called IP addresses
to refer to one another.
 For example the Habari domain uses an
IP address 193.220.91.1.
 Domain name servers translate domain
names to IP addresses, and vice versa.

Dynamic Name Servers - 3
Easy? – No, because:

There are billions of IP addresses currently in
use, and most machines have a humanreadable name as well.
 There are many billions of DNS requests
made every day. Domain names and IP
addresses change daily.
 New domain names get created daily.
 Millions of people do the work to change and
add domain names and IP addresses every
day.
Dynamic Name Servers - 4

The Domain Name System is a distributed
database, but there are central name servers
at the core of the system.
 The organization Network Solutions was
chosen to administer and maintain Internet
domain names and IP addresses. This central
database is copied to Top Level Domain
(TLD) servers around the world.
Connecting - 1
Every computer that is
connected to the Internet is
part of a network. It may be
a single PC in a home
connecting to an Internet
Service Provider (ISP).
POP = Point of Presence
Connecting - 2
At work or at school,
you may be part of a
local area network
(LAN), that connects
to the Internet.
Connecting - 4
When you connect to
your ISP, you become
part of their network.
The ISP may then
connect to a larger
network and become
part of their network.
NAP = Network Access
Points
Connecting - 5
Most large
communications
companies have
their own
dedicated
backbones
connecting various
regions.
History - 1
1962 – Vision: use computers as communication medium.
1962 – Distributed networks, packet switching.
1968 – Four computers connect through ARPA net.
1969 – First definition of protocols.
1982 – First use of TCP/IP.
1983 – Introduction of DNS
1987 – Increased public use of internet.
1989 – Invention of HTML.
1993 – Graphically-oriented World Wide Web.
1996 – Broadband internet.
History - 2
1962

Instead of thinking of computers as giant calculators,
Licklider laid out a vision in which computers would
fulfill their greatest promise as a "communication
medium between people.“

Paul Baran described a distributed telecommunication
system that could survive a nuclear strike. This
network could still work effectively even if some legs of
the network were damaged or removed. It involved a
technique called packet switching.
History - 3
1968

Four universities in the U.S. set up
interface message processors linking
computers, in the ARPA net. (Advanced
Research Projects Agency) They
provided the communications capability
required but... It also was to be a unique
prototype of future communications
systems."
History - 4
1969

The first set of protocols were defined:
Telnet and FTP functions.
Protocols are standards for exchanging
data on networks.
History - 5
1982
ARPANET
started using TCP/IP internetworking protocols. The way was open
for broader public involvement.
TCP/IP = Transmission Control Protocol /
Internet Protocol
History - 6
1987

The T1 backbone of the NSFnet
(National Science Foundation),
increasingly called the Internet, began to
get lots of attention from private
enterprises.
History - 7
1988

First commercial email carriers
connected to the Internet: MCI Mail and
CompuServe.
1989

First public dial-up Internet Service
Provider: The World Comes On Line
History - 8
1989

Tim Berners-Lee invents HTML (Hyper Text
Mark-up Language): the idea of linking text
in the documents, so there could be crossreferences from one research paper to
another.
Click here to read more.
History - 9
1989 – 1992

A tremendous
growth in internet
use.
1993

The Mosaic browser
introduces the
graphically-oriented
World Wide Web.
History - 10
1996

The first cable modem service in Canada
gives households access to broadband
internet.
This two-way, high-speed connection
can be used for interactive applications
such as online classrooms, showrooms,
or health clinics and many other
applications.
The future . . . - 1

Already operational: Internet2, a consortium of
hundreds of high-speed networks linked by
fiber optic backbones. It transmits data at
speeds up to 2.4 gigabits per second.

Scientists can share specialized equipment
like electron microscopes.

Internet-enabled devices such as cell phones
that send and receive e-mail and access the
Web.
The future . . . - 2

Virtual Collaborative Clinic that connects
medical facilities, allowing doctors to
manipulate high-resolution, 3-D images
of MRI scans and other medical imaging.
Doctors can consult and diagnose, and
simulate surgery by using a
"CyberScalpel."
The future . . . - 3

The Internet can bring entire libraries, if
not classrooms, into the home — for just
a few dollars a year.

Already “on-line universities” exist, with
more to come — accredited institutions
which facilitate studies home, using texts
and information administered over the
Internet.
Finally…

Thank you for your interest in this
presentation.

All information used in this presentation was
found on the internet.

Send me an email if you want a copy of it:
[email protected]