Transcript The Ancestors

Lecture Number One
History of the internet
and a bit about how it works
The Ancestors
ARPANET
NSFNET
ARPANET
Advanced Research Projects Agency
The original “backbone of the internet”
Purpose: to create a decentralized computer
network so government could keep working
in case of nuclear attack
More about ARPANET
- started in California in ?
- originally linked three universities (Stanford,
UCLA,UCSB) and SRI
- Designed for max of 256 computers
1976: ? ; 1984: ?
NSFNET
National Science Foundation Network
Purpose: to connect scientific researchers
and engineers
More about NSFNET
- started by the feds in ?
- originally, access limited to official
agencies
The relationship between
ARPANET and NSFNET
- ARPANET the original “backbone” of the
internet
- With NSFNET, two “backbones”
- By 1988 more than ? linked computers
How the Internet is run today
- NSFNET replaced ARPANET as backbone in
?
- Internet transferred to nonprofit corporation
? years later
How does the internet work?
Overall Internet Mechanics
All machines on the web are either servers or
clients
Servers ________ information,
clients_________ it.
Servers have numbered ports, one for each service
provided (like web access, ftp, etc)
Clients connect to the port that offers the needed
service
Whenever you are on the net
you’re part of a network
At home…
May have DSL or use a MODEM to connect to
an ISP
DSL= ? (talk & surf at the same time!)
MODEM= ?
ISP= ?
And at work…
Orgs have POP servers (point of presence)
where local users access the company’s
networks
Networks connect to each other through NAPs
(network access points)
Protocols:
How networks communicate
Protocol, defined
Internet Protocols
TCP/IP
WWW
TCP/ IP
Stands for
____________________________
Developed in the 70s for ARPANET
Formalized in 1982
TCP/IP Sends Information
from one IP address to another
- - Transmission broken into 1.5K ?
sent from router to router
- - a router is ?
- - receiving computer reassembles according
to instructions bundled with the ?
IP Addresses
- Every machine on the net has a unique
address made up of 4 numbers, 0-255,
separated by periods
-looked at in binary each number is an octetthe first is always the net, the last the host
Do you have your own IP
Address?
Yes, if you have cable or DSL (digital subscriber
line)
No, if you dial up– when you do, you’re given
the ISP address for that session which
corresponds to the MODEM that connects
you
We tend to use Domain Names
rather than IP Addresses
- At first, you had to know IP addresses
- DNs were created at the University of
Wisconsin to map text to IP addresses
automatically
What are Domain Names
- Descriptive words associated with a specific
_________________
- advantage that when machines
replaced don’t have to learn new IP address
- not case-sensitive
- must be purchased (IP addresses are
free)
Domain names made up of
First level domains (like .edu)
Second level domains (like ufl)
First level domains can’t have duplicates
But second can- spca.com not equal spca.org
Examples of first level
domain Names
.com / .org ( not necessarily nonprofit,
just don’t pay dividends)
.edu / .net
.mil/ .gov
.mx / .nl /.ch / .ca/ .uk etc.
Examples of Full Domain names
A travel agency
http://www.side-step.com/
My son's music
http://www.att.com/
Domain names are contained
within URLs
URL Stands for________________
protocol:location/document
http://www.cise.ufl.edu/~rjd/workshop06photo.html
http://www.schaferhund.com/pregnancy.htm
Some DN Considerations
Cyber squatters
Buy misspellings just in case
http://www.howstuffworks.com/
http://www.howstuffowrks.com/
Examples of multiple purchases
http://www.bn.com/
http://www.barnesandnoble.com/
http://www.barnesandnoble.com/
Some Places To Get a Domain
Name
Godaddy
RegisterFly
planetdomain
WWW
World Wide Web
protocols we use every day
finalized in _______
Some Uses of WWW Protocols
To log into remote computers (?)
To transfer web pages (?)
To transfer files (?)
To send email (?)