Agenda

The Internet and the WWW what’s the difference anyway?

History of The Internet

IP Addresses, URLs & Domain Names

READ Zeid: page 3-20

The Internet vs. World Wide Web

What EXACTLY is the difference between the Internet and the World Wide Web?

Why is it important to know the difference?

The Internet

Computers can be connected in a variety of different ways. Ethernet, Token-ring, Wireless, Ports (Serial, Parallel,

USB). These are all communication subtrates.

Two or more connected computers form a Network The CS Dept. has its own Ethernet Network

Different types of networks can be connected via bridges, gateways, etc.

The Internet

Two or more connected networks can be called an inter-network Inter-networks can obviously be connected

At some point in history, inter-networks became connected across the entire USA Eventually, inter-networks became connected across

the entire world

The entire world-wide collection of connected networks became known as The Internet.

The Internet

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)

Most experts think of The WWW as data that is accessible via a URL

(narrow definition)

All the data and services that are widely available via The Internet

(general definition)

The World Wide Web (WWW)

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.Important Note: Some companies use the Internet to share information,

but this information is only accessible through proprietary protocols,

Since, it is NOT widely available, it is not really part of the WWW.

The World Wide Web (WWW)

While the two terms are somewhat synonymous to the non-expert,

You should be aware of the difference between The Internet and the WWW

InternetWWW

Internet Jargon

In the field of Network Communications there are thousands of terms, most of which are acronyms and are not found in standard dictionaries.

The following website is good for reference:

http://www.webopaedia.com

The World Wide Web (WWW)

Examples: Content & High-level ProtocolsContent: WebPages Hypertext Transfer Protocol (http) URL (Universal Resource Locator)

Content: Data Files & Programs File Transfer Protocol (ftp)

Content: Music & Videos Gnutella Protocol

The World Wide Web (WWW)

More examplesContent: Email 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 AOL IM Protocol MSN Messenger Protocol

The Internet

Examples: Hardware & Low-Level ProtocolsHardware Computer, Ethernet card Communication Substrate:

CAT-5 cable, fiber optic cable Router, Hub, Switch, Bridge, Gateway

Low-Level Protocols/ Concepts TCP/IP (Transmission Control Protocol/Internet

Protocol) Packet Switching

What is the Internet?

The largest network of networks in the world.

Uses TCP/IP protocols and packet switching .

Runs on any communication substrate.

http://som.csudh.edu/cis/lpress/history/arpamaps/

Brief History of the Internet

1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet (Advanced Research Projects Agency)1970 - First five nodes: UCLA Stanford UC Santa Barbara U of Utah, and BBN

Brief History of the Internet

1974 - TCP protocol invented by Vint Cerf

1984 – On January 1, the Internet with its 1000 hosts converts en masse to using TCP/IP for its messaging

1968 is really the “birth” of the Internet

1984 is really the “high-school graduation” of the Internet

1962 1995

WWWCreated

1989

MosaicCreated

1993

Packet Switching Invented

1964

First Vast ComputerNetwork

Envisioned1962

ARPANET is Born

1968

TCP/IPCreated

1972

Internet Named TCP/IP Used

1984

HypertextInvented

1965

Age ofeCommerce

Begins1995

1945 1968

We can access information using

electronic computers

We do it reliably with “bits”, sending and receiving data

We can do it cheaply by using Digital circuits etched in silicon.

Great things can be done witha vast world-wide network

We will prove that packet switching works over a WAN.

Packet switching can be used to senddigitized data though computer networks

Hypertext can be used to allow rapid access to text data

1962

1968 1995

Ideas from1940s to 1968

We need a protocol for Efficient and Reliable transmission of

Packets over a WAN: TCP/IP

The ARPANET needs to convert to a standard protocol and be renamed to

The Internet

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 World Wide Web is easier to use if we have a browser thatTo browser web pages, running in a graphical user interface context.

Great efficiencies can be accomplished if we useThe Internet and the World Wide Web to conduct business.

Claude Shannon

The Father of Modern Information TheoryCreated 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

Source: http://www.research.att.com/~njas/doc/ces5.html

Vannevar Bush

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.

Source: Livinginternet.com

Paul Baran

Paul Baran developed the field of packet switching networks

Worked for RAND organization (first 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.

Source: Livinginternet.com

Leonard Kleinrock

One of the pioneers of digital network communications

Helped build the early ARPANET.

Vinton Cerf

Summary: Vinton Cerf is co-designer (with Bob Kahn) of the TCP/IP networking protocol.Worked for DARPA, projects include d the Packet Radio Net (PRNET),

and the Packet Satellite Network

(SATNET).

Source: Livinginternet.com

Tim Berners-Lee

The inventor of HTML. Now works for Laboratory for Computer Science (LCS)at the Massachusetts Institute of Technology (MIT). Directs the W3 Consortium, an open forum of companies and organizations with the mission to realize the full potential of the Web.

Source: w3c.org

Internet Growth Trends

1977: 111 hosts on Internet1981: 213 hosts1983: 562 hosts1984: 1,000 hosts1986: 5,000 hosts1987: 10,000 hosts1989: 100,000 hosts1992: 1,000,000 hosts2001: 150 – 175 million hosts2002: over 200 million hostsBy 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

0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

Time Period

No

. of

Ho

sts

The Internet was not known as "The Internet" until January 1984, at which timethere were 1000 hosts that were all converted over to using TCP/IP.

Chart by William F. Slater, III

Sept. 1, 2002

Dot-Com Bust Begins

Internet’s Growth

To get a market of 50 Million People Participating: 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!

URLs

Universal Resource Locator

www.cs.siena.edu

Human-readable WWW Address

IP Address

Numeric Internet Address

Part of the TCP/IP Protocol

URLs are translated into IP Addresses by DNS Servers

DNS Domain Name System