Transcript Document

For those who forgot:
CSIS-116: Survey of Information
Technology
Dr. Eric Breimer
Recap of last class
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Course Topics
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Syllabus
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Internet
Web meets DB
E-commerce
Come to lecture
Don’t miss exams
Don’t cheat
Other non-sense
Agenda
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The books
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Info. Tech (IT) inside and out
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Dreamweaver MX
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WPI nerds
Reference manual
Chapter 2: IT pages 15-33
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The Internet and the WWW (what’s the difference?)
History of The Internet
What exactly is the World Wide Web
The Books
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I’ll call it “IT”
Written by two
Electrical/Computer
Engineers
Covers the basics of
how things work
Why I picked it?
Covers exactly the
topics I think are
important
The Books
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I’ll call it
“Dreamweaver”
Reference manual
Will come in handy
during lab.
This is an awesome
book.
Don’t sell it.
Chapter 2: The World Wide Web
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A Unique Product of the Information Age
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Whatever that means?
Exam Question #2: What EXACTLY is the
difference between the Internet and the
World Wide Web?
Stupid Question #1: Why is it important to
know the difference?
The Internet
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Computers can be connected in a variety of different
ways.
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Two or more connected computers form a Network
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The CS Dept. has its own Ethernet Network
Different types of networks can be connected
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Ethernet, Token-ring, Wireless, Ports (Serial, Parallel, USB).
These are all communication subtrates.
Bridges, gateways, etc.
Two or more connected networks can be called an
inter-network
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Siena had a very complex Inter-Network until recently.
Wanna see it?
The Internet
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Inter-networks can obviously be connected
At some point in history, inter-networks
became connected across the entire USA
The entire nation-wide collection of
connected networks became known as The
Internet.
Eventually, inter-networks became connected
across the entire world
The Internet
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The text book doesn’t mention this…
Most experts in the “Network World” think of The
Internet as both
– The physical infrastructure (wires, routers, hubs,
switches, satellites, optical cables, receivers,
transmitters, etc.) that form the inter-connections.
– And, the actual collection of computers (and
devices) that are “inter-connected.”
The World Wide Web (WWW)
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Most experts think of The WWW as
– HTML documents that are accessible via a URL (very
narrow definition), or
– All the data, information, and services that are widely
available via The Internet (more general definition)
Thus, The Internet is the physical hardware that makes the
connections possible and
The World Wide Web is the content and services that are
widely available over this massive collection of connected
computers.
The World Wide Web (WWW)
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While the two terms are somewhat
synonymous to the non-expert,
You should appreciate the subtle difference
in the two terms.
Some examples and history might help…
The World Wide Web (WWW)
Examples: Content & High-level Protocols
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Content: WebPages
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Content: Documents & Programs
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Hypertext Transfer Protocol (http)
URL (Universal Resource Locator)
File Transfer Protocol (ftp)
Content: Music & Videos
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Gnutella Protocol
The World Wide Web (WWW)
More examples
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Content: Email
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SMTP (Simple Mail Transport Protocol)
IMAP (Internet Message Access Protocol)
POP (Post-Office Protocol)
DNS (Domain Name System)
MIME (Multipurpose Internet Mail Extensions)
Content: Peer to Peer messaging
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AOL IM Protocol
Multi-player gaming (various protocols)
The Internet
Examples: Hardware & Low-Level Protocols
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Hardware
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Computer, Ethernet card
CAT-5 cable, fiber optic cable
Router, Hub, Switch, Bridge, Gateway
Low-Level Protocols/ Concepts
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TCP/IP (Transmission Control Protocol/Internet Protocol)
Packet Switching
What is the Internet?
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The largest network of networks in the world.
Uses TCP/IP protocols and packet switching .
Runs on any communications substrate.
From Dr. Vinton Cerf,
Co-Creator of TCP/IP
Brief History of the Internet
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1968 - DARPA (Defense Advanced Research Projects Agency)
contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet
(Advanced Research Projects Agency)
1970 - First five nodes:
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UCLA
Stanford
UC Santa Barbara
U of Utah, and
BBN
1974 - TCP specification by Vint Cerf
1984 – On January 1, the Internet with its 1000 hosts
converts en masse to using TCP/IP for its messaging
A Brief Summary of the
Evolution of the Internet
TCP/IP
Created
1972
Internet
Named
and
Goes
TCP/IP
1984
Mosaic
WWW Created
1993
Created
1989
Age of
eCommerce
Begins
1995
ARPANET
1969
First Vast
Computer
Network
Envisioned
1962
1962
Packet
Switching
Invented
1964
Hypertext
Invented
1965
1995
Ideas 1940s to 1969
We will prove that packet switching
works over a WAN.
Hypertext can be used to allow
rapid access to text data
Packet switching can be used to
send digitized data though
computer networks
We can accomplish a lot by having a
vast network of computers to use for
accessing information and exchanging ideas
We can do it cheaply by using
Digital circuits etched in silicon.
We do it reliably with “bits”,
sending and receiving data
We can access
information using
electronic computers
1945
1969
Ideas 1970s to 1995
Great efficiencies can be accomplished if we use
The Internet and the World Wide Web to conduct business.
The World Wide Web is easier to use if we have a browser that
To browser web pages, running in a graphical user interface context.
Computers connected via the Internet can be used
more easily if hypertext links are enabled using HTML
and URLs: it’s called World Wide Web
The ARPANET needs to convert to
a standard protocol and be renamed to
The Internet
We need a protocol for Efficient
and Reliable transmission of
Packets over a WAN: TCP/IP
Ideas from
1940s to 1969
1970
1995
Vannevar Bush
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Summary: Vannevar Bush established the
U.S. military / university research partnership
that later developed the ARPANET. He also
wrote the first visionary description of the
potential use for information technology,
inspiring many of the Internet's creators.
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From 1946 to 1947, Bush served as chairman
of the Joint Research and Development
Board. Out of this effort would later come
DARPA, which would later do the ARPANET
Project.
Source: Livinginternet.com
Claude Shannon
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The Father of Modern Information Theory
Created the idea that all information could be
represented using 1s and 0s. Called these
fundamental units BITS.
Won a Nobel prize for his master’s thesis in 1936,
titled, “A Symbolic Analysis of Relay and Switching
Circuits”, it provided mathematical techniques for
building a network of switches and relays to realize
a specific logical function, such as a combination
lock.
Source: http://www.research.att.com/~njas/doc/ces5.html
Paul Baran
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Source: Livinginternet.com
Summary: Paul Baran developed the field of
packet switching networks while conducting
research at the historic RAND organization.
RAND (a contraction of the term research and
development) is the first organization to be
called a "think tank.“
Baran's architecture was well designed to
survive a nuclear conflict, and helped to
convince the US Military that wide area digital
computer networks were a promising
technology.
Leonard
Kleinrock
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Lawrence
Roberts
Summary: Leonard Kleinrock is
one of the pioneers of digital
network communications, and
helped build the early
ARPANET.
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Summary: Lawrence Roberts was the
ARPANET program manager, and led the
overall system design.
Source: Dr. Kleinrock’s Homepage
Vinton Cerf
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Source: Livinginternet.com
Summary: Vinton Cerf is co-designer of
the TCP/IP networking protocol.
Cerf worked on several interesting
networking projects at DARPA, including
the Packet Radio Net (PRNET), and
the Packet Satellite Network (SATNET).
In the spring of 1973, he joined Bob
Kahn as Principal Investigator on a
project to design the next generation
networking protocol for the ARPANET.
Robert Kahn
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Summary: Bob Kahn is co-designer of the
TCP/IP networking protocol.
He set four goals for the TCP design:
Network Connectivity. Any network could
connect to another network through a gateway.
Distribution. There would be no central network
administration or control.
Error Recovery. Lost packets would be
retransmitted.
Black Box Design. No internal changes would
have to be made to a computer to connect it to
the network.
Source: Livinginternet.com
Tim Berners-Lee
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Source: w3c.org
The inventor of HTML. Graduate of Oxford
University, England, Tim is now with the
Laboratory for Computer Science (LCS)at the
Massachusetts Institute of Technology (MIT).
He directs the W3 Consortium, an open
forum of companies and organizations with
the mission to realize the full potential of the
Web.
Internet Growth Trends
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1977: 111 hosts on Internet
1981: 213 hosts
1983: 562 hosts
1984: 1,000 hosts
1986: 5,000 hosts
1987: 10,000 hosts
1989: 100,000 hosts
1992: 1,000,000 hosts
2001: 150 – 175 million hosts
2002: over 200 million hosts
By 2010, about 80% of the planet will be on the Internet
Important Milestones
September 2002
Netsizer.com – from Telcordia
Growth of Internet Hosts *
Sept. 1969 - Sept. 2002
250,000,000
Sept. 1, 2002
No. of Hosts
200,000,000
150,000,000
100,000,000
Dot-Com Bust Begins
50,000,000
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Time Period
Chart by William F. Slater, III
The Internet was not known as "The Internet" until January 1984, at which time
there were 1000 hosts that were all converted over to using TCP/IP.
Statistics from the IITF Report
The Emerging Digital Economy *
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To get a market of 50 Million People Participating:
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Radio took 38 years
TV took 13 years
Once it was open to the General Public, The Internet
made it to the 50 million person audience mark in just 4
years!!!
http://www.ecommerce.gov/emerging.htm
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Released on April 15, 1998
Questions?
Sources of Statistical Information
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Netsizer.com – from Telcordia
CAIDA
Network Wizards Internet Domain Survey
RIPE Internet Statistics
Matrix Information and Directory Services
Growth of the World Wide Web
The Netcraft Web Server Survey
Internet Surveys
The Internet Society