- You all know
the Internet....
- Question:
- Why was the Internet built/created ????
- Fact:
- A communication network is
determined by the
communication protocol used
(by that network)
- The protocol specifies how to interpret certain information fields in a message
- A communication network is
determined by the
communication protocol used
(by that network)
- Analogy:
- What's the difference between
FedEx and
UPS ?
Difference:
- Each carrier
uses its own way to
identify a
package
(i.e.,
different addressing
(= tracking numbers !!))
- Each carrier uses its own
code to
identify the
cities
- Each carrier uses its own
hubs to
forward the
packets
- And so on...
- Each carrier
uses its own way to
identify a
package
(i.e.,
different addressing
(= tracking numbers !!))
Result:
- A FedEx package
can not be
processed at a
UPS processing hub
- And vice versa !!!
- What's the difference between
FedEx and
UPS ?
- What is the Internet:
- Internet = a
network that uses the
IP protocol to
transmit messages
- IP protocol = the Internet Protocol ( click here)
- Internet = a
network that uses the
IP protocol to
transmit messages
- Fact:
- There were various different
computer networks
before the Internet
Note:
- Each type of computer network uses its own protocol
Consequence:
- Messages sent on one type of network cannot be sent on another type of network without changing the message format
- There were various different
computer networks
before the Internet
- Some mile stones
in computer communication
before the
creation of the
Internet:
- 1969:
ARPAnet
(the first
computer network)
- ARPAnet connecting: UCLA, UCSB, Unib. of Utah and Stanford Research Institute.
- ARPAnet does not use the Internet Protocol (IP) !!!
- 1971:
first email sent on ARPAnet !
(Yes, there can be email without using the Internet !) - 1971:
File Transfer Protocol
(ftp) introduced
Note:
- Networking is clearly
useful
(can you live without email ??!!)
- Other people/institutes now
want to be connected to
each other....
- I think if they have expanded the
ARPANet to connect
other computers in the
world, you do not need to
invent the
Internet.....
- Anyway, other people/institute
now starts to make
their own
communication networks....
(They do not get on the ARPANet because they were not sponsored by ARPA.....)
- Networking is clearly
useful
(can you live without email ??!!)
- 1978:
UUCP (Unix to Unix copy)
communication protocol -- mainly used for
software distribution between
UNIX systems.
- 1980 and beyond:
Other networks are starting to be developed and employed
- It was the start of chaos...
- I can remember I needed to use several types of email addresses to send my emails; depending on where I wanted to send the email....
- It was the start of chaos...
- 1969:
ARPAnet
(the first
computer network)
-
Some well-known
computer networks
created after the creation
of ARPANet:
- CSNet
(1981)
was established to connect computers from
various computer science department
of (poorer) universities
-
See:
click here
- The Computer Science Network (CSNET) was a computer network that began operation in 1981 in the United States.[1] Its purpose was to extend networking benefits, for computer science departments at academic and research institutions that could not be directly connected to ARPANET, due to funding or authorization limitations.
So the reason why other institutes start their own networks is because they cannot get on ARPANet.....
- BITNet was another alternative to
ARPAnet
(1981)
- See:
click here
- BITNET was a cooperative USA university computer network founded in 1981 by Ira Fuchs at the City University of New York (CUNY) and Greydon Freeman at Yale University.
- FidoNet
(1984)
mostly for Bulletin boards -
See:
click here
- FidoNet is a worldwide computer network that is used for communication between bulletin board systems (BBSs). It uses a store and forward system to exchange private (email) and public (forum) messages between the BBSs in the network, as well as other files and protocols in some cases.
- etc, etc
- CSNet
(1981)
was established to connect computers from
various computer science department
of (poorer) universities
-
See:
click here
- Emerging problem:
- Each type of network
uses a different communication protocol
-
it is like people from different countries speaking different languages.
-
Computers on different types of networks
cannot communicate
with one another
without
using some kind of
communication protocol
translation
software.
- Addressing
(identifying a user)
was a pain:
you had many different
address formats !!!
- Relaying a message from one network to another network was a nightmare (the more networks there were, the more translation routines needed !)
- Addressing
(identifying a user)
was a pain:
you had many different
address formats !!!
The solution:
- Get rid of all the
networks that have been
created
- Connect all computers on
one network:
- The Internet.....
The new Internet uses the the Internet Protocol (IP) created
- Each type of network
uses a different communication protocol
-
it is like people from different countries speaking different languages.
- Self-proclaimed father of the Internet:
Al Gore :)
- Al Gore ???
(LOL :))
Al Gore: "During my service in the United State Congress, I took the initiative in creating the Internet
Yeah, right:
Full article: click here
(He's the perfect Politician for me to teach recursion: do very little work and claim all the glory....)
- Al Gore ???
(LOL :))
- The real creators of the
Internet:
-
Robert Kahn
(
click here)
and
Vinton Cerf
(
click here)
-
Robert Kahn
(
click here)
and
Vinton Cerf
(
click here)
- Different versions of
the Internet
- There is no one version of
the Internet !!!
- There are many different versions of the Internet !!!!
- The most popular version of the
Internet Procotol used is:
verions #4 (IPv4) !!!
- There is no one version of
the Internet !!!
- Development of IPv4:
- 1974: document Specification of Internet "Transmission Control Program", by Vinton Cerf, Yogen Dalal and Carl Sunshine, Network Working Group (TCP v1)
- ??? --- TCP v2,
- Spring 1978: TCP/IP version 3 - splits the original protocol into 2 protocols: TCP v3 and IP v3
- September 1981:
the IP standard
(IPv4 -
Internet Protocol version 4)
- January 1, 1983: flag day --- all protocols replaced by IPv4 !!!
- The calm before the
storm:
- For a long time,
the Internet was
the best kept secret
of the academia...
- The Internet was
mainly used for:
- news (USENET)
It was quiet and peaceful on the Internet - the good old days :-)...
- For a long time,
the Internet was
the best kept secret
of the academia...
- This killer application
put the Internet
in the public spot light....
- 1993:
Mosaic
What is Mosaic:
- Mosaic
was the grand-daddy of
Netscape
(or the present day
Mozilla firfox)...
See: click here
- With Mosaic, a user can share the information stored in his
website easily with anyone on the Internet
- The World Wide Web (WWW) was born....
- 1993:
Mosaic
- Mosaic companion:
- But there is still a problem: unless you
tell someone about your website,
nobody can find it...
- 1994:
Webcrawler
- See:
click here
- Webcrawler
was the
first Web search engine
-
you can say it's the grand-grand-grand-daddy of
Yahoo
and
Google
and
other web page search engines...
- With Webcrawler, a user can find the relevant information !
- Webcrawler
was the
first Web search engine
-
you can say it's the grand-grand-grand-daddy of
Yahoo
and
Google
and
other web page search engines...
The rest is history....
Soon everybody wanted a website....
Problem:
- The Internet start to
run out of
Internet Addresses
(It's like the telephone company running out of xxx-xxx-xxxx telephone numbers !!!)
- But there is still a problem: unless you
tell someone about your website,
nobody can find it...
- 1994:
IPv6
-
Internet Protocol version 6
(See:
click here)
- As with any good thing,
the Internet was
a victim
of its own success
- Each computer
on the Internet requires a
unique IP address
(like your own
telephone number)
- IPv4 has
232 =
4294967296
numbers...
The world is running out of IPv4 addresses
- New Internet Protocol:
IPv6
supports
2128 =
340282366920938463463374607431768211456
addresses... Oh, yeah, baby :-)
Unfortunately, changing over to IPv6 is not easy and still has not happened in 2014....
- We found many ad hoc fixes
to limit the
number of IPv4 addresses
used
- The US still uses
IPv4
- Many other countries have switched to IPv6
- We found many ad hoc fixes
to limit the
number of IPv4 addresses
used
- As with any good thing,
the Internet was
a victim
of its own success
- IPv4 and
IPv6:
- Today, the Internet uses
a mix of
IPv4 and
IPv6 protocols.
- There are many ways
to allow IPv4 and IPv6 to
"co-exist"
Article: click here
(The techniques mentioned in the article will be discussed in this course - but not specifically in relationship with IPv4 and IPv6)
- Today, the Internet uses
a mix of
IPv4 and
IPv6 protocols.