The Internet

It’s a jungle out there …

In the beginning … The Advanced Research Projects Agency

NETwork (ARPANET) is the predecessor to the Internet:– Developed at the request of the Department of

Defense by a team of visionary computer scientists – Launched in 1969– Its peer-to-peer networking philosophy and

protocols were copied in other networks in the 1980s

– Disbanded in 1990, having fulfilled its research mission, but its technology spawned the Internet

THE INTERNET The Internet: an interconnected

network of thousands of networks – Links academic, research, government,

and commercial institutions Connects computers all over the

world. – Growing too fast to measure its growth– Too decentralized to quantify– A network with no hard boundaries

How does the information flow?

Transmission Control Protocol/Internet Protocol, TCP/IP…– At the heart of the Internet– Allows cross-network communication

TCP Transmission Control Protocol breaks

messages into packets– Each packet has all the information

needed to travel from network to network

IP Address Host systems called routers determine

how to route transmissions– IP is the address for the packets– Each Internet host computer has a unique

IP address (about 3.3 billion available)– Each address is comprised of four sets of

numbers separated by periods, such as 123.23.168.22

Address for the

www.thestar.ca is really 192.206.150.210

Internet Addresses The host is named using DNS (domain name

system), which translates IP addresses into a string of names– Top-level domains include:

.edu - educational sites

.com - commercial sites

.gov - government sites

.mil - military sites

.net - network administration sites

.org – non-profit organizations

Internet Addresses Ctd. Every country also has a unique

domain .ca – Canada

.us – United States

.uk – United Kingdom

.jp – Japan

.tv - Tuvalu

$ Tuvalu $ 11,636 people on a tiny group of

islands In 2000 a California company DotTV

agreed to pay Tuvalu $50 million for the right to auction .tv domains for the next 12 years.

Web page Protocols

HTML was created for encoding and displaying documents

An HTML document includes code that determines the format, layout, and structure of a Web document

Hyper Text Markup Language Hyperlink – a link to another document

What the “www” World Wide Web Designed in 1989 by Tim Berners-Lee

a scientist An easy method of surfing the Internet

(loading documents)

Life before WWW

URL need this … Uniform Resource Locator - a

standard naming scheme for every information resource on the Internet

A typical URL looks like this: http://www.bwdsb.on.ca/

URL Breakdownhttp://www.uoguelph.ca/admissions/event/index.cfm

http://www.uoguelph.ca/admissions/event/index.cfm

Hyper Text Transfer Protocol

Domain Name

Domain Extension

Path

File Resource

Web browser An application for viewing documents

from remote locations They translate HTML into readable text

and pictures

Internet Access

Connection Speed Slower when

Cost ($)/month

Dialup Phone and modem

56 Kbs Modem is junk

$10-20

DSL Shares phone line

Up to 50x faster

Further you are from switch

$40-50

Cable Shares cable TV line

Up to 100x faster

More users online

$40-50

Sources http://www.let.leidenuniv.nl/history/ivh/chap2.

htm http://computer.howstuffworks.com/nat.htm http://www.toolsforselling.com/v1/1/iplookup.

htm http://www.iana.org/cctld/cctld-whois.htm http://www.informationweek

.com/story/IWK20000414S0001 http://www.cia.gov/cia/publications/factbook/

geos/tv.html