Presentation made in the European Parliament on 23 May 2011 to explain in a simple way some basics of the Internet.

1. 1st Session
Caroline De Cock & Peter Van Roste
1

2. Putting things
in perspective:
what will happen
on the Internet
during the next
hour?
2

3. 13 billion
emails
The amount of emails
sent per hour
2100
hours
The amount of YouTube
Videos uploaded every hour
3

4. How is this possible?
4

5. #1. Something started 42 years ago
for military & academic purposes
was opened to commercial companies
5

6. #2. And the
technology to
make it work was
made open
6

7. So
what’s
the
Internet
7

8. The Internet is a bunch
of computers and
cables linked to each
other and that can
communicate across
the globe
8

9. The Internet is the worldwide, publicly accessible
network of interconnected computer networks
that transmit data by using the
standard Internet (IP). It is a "network
of networks" that consists of millions of smaller
“
domestic, academic, business, and government
networks, which together carry various
information and services, such as electronic mail,
online chat, file transfer, and the interlinked Web
pages and other documents of
9

10. 10

11. All of this translates into a multitude of
players
Source: OECD, The economic and social role of
11
Internet intermediaries, April 2010

12. From POTS* to the Net
Traditional telephony is based on
circuit switching, which implies:
• Communication flow follows
a path that is selected
beforehand and that remains
fixed during the session
• This path is dedicated
*Plain Old Telephony Services
12

13. So this is what a circuit switched network
looks like
13

14. Packet switching
The Internet is based on packet
switching, which implies:
• The sending computer slices data
into small packets, with an address
on each to tell the network where
to send them
• These packets are sent as need be
and in what looks like a chaotic
flow
• At the end, the receiving computer
puts the puzzle back together
14

15. 1000 to 1500 bytes
Header Body/Data Footer
But what’s - Sender &
Receiver
- Data (e.g. The
content of an email)
-Data to
show end
IP address of packet
in a packet? - Protocol
- Packet n°
- Error
correction
15

16. So this is what a packet switched network
looks like
16

17. And to make all of this work, you need a
common language: PROTOCOLS
Application Layer
Transport Layer
Network Layer
Data / Link Layer
Physical Layer
17

18. And to function, these protocols need
to go through ports
File transfer Email Web browsing VoIP
FTP SMTP HTTP SIP
Ports Port Port Port
20 or 21 25 80 5060
Transport Layer
18

19. ...OK but what happens between this
19

20. ...and that?
20

21. #1. Find server
62.25.101.80
#2. Process query
#3. Assembly
#4. Return to PC
21

22. Disclaimer
22
Source: http://909sickle.com/s/geeks-and-nerds/

23. Disclaimer (cont’d)
23