International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B6. Istanbul 2004 
1000 hosts 
1984 
Birth of the TCP/IP protocol 
Birth of WWW 
30 millions users 
1996 
Explosion of Internet/Web as 
  
Internet adopted and HTML the Web information 
superhighway 
» 
1969 80's 1990 2000 
1974 1993 1998 
TCP Specification 
MOSAIC browser 
30 millions hosts 
Figure 1: The history of the Internet, summarise in few key points. 
University of New York; NSFNET, initiated by the U.S. 
National Science Foundation (NSF); NSINET, developed by 
NASA; CSNET (Computer Science NETwork), developed by a 
group of computer scientists and some university. By that time 
Internet was an essential tool for communications, however it 
also began to create concerns about privacy and security in the 
digital world and new words, such as "hacker" or "cracker" 
were created. 
In 1990 ARPANET ceased to exist while the country already 
connected to NSFNET were 28 with ca 300.000 hosts. The 
NSFNet soon connected to the CSNET, which linked 
Universities around North America, and then to the EUnet, 
which connected research facilities in Europe. 
Tim Berners-Lee, researcher at CERN of Geneva, noticed that 
many people were having difficulties in sharing information 
due to a range of different network information retrieval 
protocols and a range of workstation types with widely varying 
display capabilities. For this reason he proposed an Internet- 
based hypertext system which would have linked together 
behind a single and easy-to-use interface the various 
information spread around the Internet. He produced a WWW 
browser-editor which reads HyperText Markup Language 
(HTML) documents from Uniform Resource Locator (URL) 
addresses: i.e. the Web was born [Berners-Lee, T., 1990]. 
In the next years the Internet Society (ISOC) was founded 
(1991); the World Bank goes on-line (1992); Mosaic, the first 
commercial graphical Web browser was released by Eric Bina 
and Mark Andreesen (1993); "Yahoo" (Yet Another 
Hierarchical Officious Oracle) was invented by two PhD 
students from Stanford University (1994); NSFNET reverted 
back to a research project and left the Internet in commercial 
hands. And in 1995, The Federal Networking Council (FNC), 
in consultation with the leadership of the Internet and 
Intellectual Property Rights Communities, unanimously passed 
a resolution defining the term Internet [FNC Resolution, 1995]. 
Figure 1 shows a brief history of the Internet, from its origin to 
our time. As the Internet celebrates its 30th anniversary, the 
military strategies that influenced its birth become historical 
footnotes. Approximately 500 million people (in almost 250 
countries around the world) were already connected to the 
global net and the traffic on it expanded at a 340% annual 
growth rate. The number of computer hosts approached 100 
million and the Internet passed from a Cold War concept to the 
Information Superhighway. All the rest is no more history: as 
new generation will grow up accustomed to communicate using 
a keyboard, life on the Internet will become an increasing 
important part of our life. 
112 
2.2 How does the Internet work? 
Since 1969, the Internet has grown from four host computers in 
U.S. to millions of computer worldwide. However, even if 
nobody owns the Internet, it is monitored and maintained in 
different ways. There are organisations that define how we use 
and interact with the Internet. The ISOC, Internet Society 
[ISOC], oversees the formation of the policies and protocols. 
The World Wide Web Consortium [W3C, 2004], created in 
1994, tries to lead the World Wide Web to its full potential by 
developing common protocols that promote its evolution and 
ensure its interoperability. The Internet Corporation for 
Assigned Names and Numbers [ICANN, 2004], a non-profit 
corporation formed in 1998 to assume responsibility for the IP 
address space allocation, protocol parameter assignment, 
domain name system management and root server system 
management, all functions previously performed under U.S. 
Government contract by IANA (Internet Assigned Number 
Authority) [IANA, 2004] and other organisations. They all 
assume responsibility for technical function, provide reliable 
information about the Internet and develop interoperable 
technologies (specifications, guidelines, software and tools) to 
lead the Web to its full potential as a forum for information, 
commerce, communication, and collective understanding. 
    
    
Figure 2: A visualization of the Internet traffic in north 
America. The colored lines represent virtual connections from 
the network sites to the backbone [NCSA ]. 
In general, all the machines on the Internet can be divided in 
two types: servers and clients. Those machines that provide 
services (like Web servers or FTP servers) to other machines 
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