- How has the Internet developed?
- Internet Structure
- The World Wide Web
When most people think of the Internet,
they think of a computer screen with pretty text and images-
the World Wide Web page we are so used to. But the Internet is
nor the same as a web page. It predates the Web, and has many
other functions. What with email, news groups, videoconferences,
chats, voice over IP, p2p networks, etc (none of these are web
based), the list is huge and getting bigger.
How has the Internet developed?
The internet began in the USA during
the Cold War. When the Soviet Union placed the Sputnik satellite
into space in 1957, the US military was shocked, which led to
the creation of the Advanced Research Projects Agency (ARPA).
One of ARPA’s projects was to investigate large-scale networking
of computers, especially to allow collaboration between scientists
and researchers. It was to be a decentralised network, without
a central focus or control point, so that if one node in the
network failed, the others could take over its role. The decentralised
nature of the intetrnet is said to have been inspired by the
idea of surviving a nuclear attack. A centralised communication
system could be put out of action easily with a missile, but
if all the points on the network could replace the destroyed
node, if none was essential to the functioning of the network
as a whole, then the system would be able to withstand at least
limited damage. In fact, the initial motivation was more how
to avoid centralised control, and the need to stimulate cooperation
amongst researchers. And it was to be open to connection with
other systems via publicly available standards.
In 1969, ARPA scientists connected two (and soon thereafter,
four) mainframe computers (there were no PCs then) in different
states of the USA, and began to send data to each other via a
rudimentary packet system, the beginnings of the internet protocols
that we use now.
Thus ARPANET was born, and was presented to the public in 1972.
By then, simple email was possible, com-puter-to-computer chats
followed, and other countries began their own research networks.
In 1979, USENET brought us news groups, but at that stage only
a few hundred computers were involved. Of course, the Web still
did not exist, everything was text-based and, although other
networks were created in the USA, Canada and Europe, which were
similar to ARPANET, they still were not all interconnected.
The first Internet
The idea was to type ‘login’ at
UCLA and see if this appeared on the other computer
at Stanford University.
"We set up a telephone
connection between us and the guys at SRI...," Kleinrock
... said in an interview: "We typed the L and
we asked on the phone,
"Do you see the L?"
"Yes, we see the L," came the response.
"We typed the O, and we asked, "Do you see the O."
"Yes, we see the O."
"Then we typed the G, and the system crashed"...
Yet a revolution had begun"...
Source: Sacramento Bee, May 1, 1996,
p.D1, cited in The Roads and Crossroads of Internet
History by Gregory R. Gromov, http://www.netvalley.com/intval1.html
But what they were beginning to share
was the fundamental basis of the internet, the TCP and IP protocols.
Formally adopted in 1982, these technical standards allow the
internet to function as a decentralised network of interconnected
computers. The TCP protocol defines the way data is broken down
into manageable chunks, or packets, which are then sent individually
through the internet. Imagine a large letter is broken up into
separate pages. Each page is put into its own envelope and then
into the post box. When they reach their common destination,
they are put back together to create the original file or piece
of data. This is more efficient than, for example, a continuous
flow of data, because if one of the packages is lost, it can
be re-requested and sent without having to re-send all the data,
causing less errors and less wasted time.
The IP protocol controls the way
the packets reach their destination, a kind of addressing system
based on IP numbers such as 220.127.116.11. It is a bit like
the address on an envelope. Each computer on the route to the
destination knows how to send the packet to its IP destination,
choosing the best route according to which computers are available
and connected at each point in time. There is no direct connection
between the origin and the destination, and the route is not
decided in advance before the journey begins. Routers decide
where to send the packets, depending on which other hosts are
available, and the packets jump from one host to another until
they finally reach their destination. To be on the internet,
you need an IP number, as well as a physical connection such
as a phone line, an Ethernet or cable connection. In theory,
no IP number is more important than another – the internet
has no central brain or headquarters. In practice, as we will
see, some IP numbers, such as those assigned to the DNS databases,
routers and backbone nodes, are more important than others.
This system is different from the
traditional information flow used in the telephone system, called
circuit switching. Here, the flow of information is continuous,
along one channel, and if this circuit is broken the connection
is lost and communication stops. But in packet switching, if
the flow is stopped for some reason, then the routers are able
to find alternative routes, and not all packets need to follow
the same routes as each other before they are brought together
and reassembled at their destination.
By 1984, the number of IPs was around
a thousand, and it was impossible to remember them all, so the
Domain Name System (DNS) was introduced. This meant that an internet
address could be made up of words, not just numbers. When you
typed in the address, whether in email, or a news group (remember,
at that stage there was still no WWW or hypertext), your programme
asked a central database for the IP number that corresponded
to that name, and used that IP number to send the packets to
their destination. For a name to work it had to be registered
first; otherwise it would not be in the data-base. All internet
name addresses (as distinct from IP addresses) must use a domain.
The first domains were .mil, .edu, .com, .org, and country domains
such as .uk were introduced from 1985. That same year, the task
of running the DNS database was given to the Information Sciences
Institute (ISI) at University of Southern California (USC), and
domain name registration was run by the Stanford Research Institute
(SRI). The internet was still very much a network for researchers,
and the organisations that ran it were university-based. In 1986,
the National Science Foundation set up NFSNet, which provided
a backbone of fast fibre optic connections to which other centres
in the USA, mostly universities, could connect easily. The Internet
Engineering Task Force was set up the same year to decide on
the technical standards for the entire internet also with a little
US university funding. This means that the US government essentially
paid for the physical infrastructure and the running of the en-tire
network, with the exception of those networks in other countries
which were beginning to connect up to the US network, and which
were research networks funded in turn by their own governments.
There was still no commercial internet, and almost all users
were from universities or research institutes. It was not until
1993 that the introduction of the graphical World Wide Web made
it much easier to present and find information on the internet.
Together with the commercial exploitation of the internet, which
took off around 1994, this created the expansion boom that has
led to the millions of users we have now.
How does the internet work now? The
underlying basis is the same: a whole lot of computers connected
up to transfer data from one to the other. Data can flow through
fibre optic cables, copper wires, coaxial cables, copper telephone
lines, satellite connections, wireless, Ethernet cables, etc.
It still uses the TCP/IP protocol that moves the data from place
to place. On top of this, there are various other protocols that
allow us to do useful things with the data. For example, the
SMTP protocol sends email on its way to another internet server.
It is not necessary to use the SMTP server on your own ISP system,
although most systems are protected from external spammers so
that only that ISP’s users can access the data. The HTTP
protocol allows your web browser to send a request for one or
more web files to another computer (web server). When the text
and graphics files reach your browser, it interprets the HTML
language in the text files, laces the graphics and the colour
in the appropriate place, and assembles them all to create the
visually-pleasing page you see on your screen. The POP protocol
allows us to login to a POP server and download our mail to be
stored on our own computer, rather than only view it on a web
page while we are connected to the internet. IMAP allows many
other kinds of files and applications, such as audio and video,
to function together via the web.
To connect to the internet, you can be on a local network which
is connected already, as in a library or university, or have
a special cable which connects you directly, such as a leased
line (a special cable leased from the telecommunications company
which provides fast but expensive access) or a cable TV connection,
or have a contract with a company which provides a satellite
connection, or through a local wireless connection point. Most
people however, connect via the telephone system with a modem
or ADSL, using their telephone wire (via the ‘local loop’ between
the telephone and the telephone exchange) because it is cheaper
and more readily available. In general, the faster the connection,
the more it costs.
When you connect via a commercial link, it is normal to do that
through a company or Internet Service Provider (ISP), which has
a permanent connection to the internet and charges you for sharing
this connection with hundreds or thousands of other users. The
ISP only routes local traffic to a commercial carrier, usually
a telecommunications company or a huge ISP, with a further connection
to the main highways of the internet, which most people never
see. The first of these backbone carriers was NFSNet, back in
1986, but now huge companies, such as UUNet, Sprint, and ATT,
run the most important internet infrastructure. They connect
to each other through Major Exchange Points (MAPs, MAEs, etc)
and in this way the internet extends over the face of the planet.
So we have:
1. End users
4. Major Exchange Points
5. Backbone carriers
Most of this infrastructure is owned
and managed by private enterprise, not, for example, by governments,
and hardly ever by community organisations. This early privatisation
has had important consequences for the future development of
the Internet, and this is explored in more detail in chapters
3 and 4.
The World Wide Web
The early internet had no graphics.
Everything was in text form: letters, numbers and symbols on
the screen. The introduction of the World Wide Web (‘the
Web’) revolutionised the internet, making it more attractive,
more versatile and easier to use. The Web was initially conceptualised
by Tim Berners-Lee and other scientists at the European Centre
for High Energy Physics (CERN) in Geneva, Switzerland in 1989,
and a simple – and free
– browser was released to the public a year later. Initially
progress was slow, with no more than 150 web sites in the world
by the end of 1993. It was the creation of the Mosaic browser
programme by Mark Andreeson in 1993 that simplified enormously
the use of the Web and made the pages so easy to read and visually
pleasing. This was the predecessor of Netscape and Microsoft
Explorer. The programme was made available to the public, especially
to the educational community, and it rapidly replaced the text-based
tools for information retrieval like Gopher, Archie and Veronica
that had been used before. In 1994, the WWW edged out telnet
to become the second most popular service on the Net (behind
ftp-data) based on the percent of packets and bytes traffic distribution
on NSFNET, and a year later it became – and has remained
– number one.
It was in 1994 that private enterprise started using the internet,
with the commercial sites and the first virtual shopping malls
and cyberbanks. In 1995, NFSNet became a research network again,
and the infrastructure was now firmly in the hands of private
enterprise. The internet began to be sold as a commodity, and
it sold well. In 1994, there were 3,000 web sites and a year
There are many problems with this way of financing internet infrastructure.
To begin with, monopolies in the telecommunications industry
can mean that prices are artificially high and competition is
minimal. The USA dominates the internet, both in terms of number
of users and amount of content. Economies of scale mean that
it is cheaper to connect to the internet in the USA than in other
parts of the world, since the infrastructure there is better
developed and US companies control it worldwide. And, because
of the way ISPs are charged for their connectivity, it is more
expensive for ISPs in poor countries than in rich ones. Coupled
with higher fees for telephones, the result is that users in
poor countries have to pay much higher prices than those who
can afford to pay more. This means that very few can benefit
from the advantages of the internet in those countries. Internet
infrastructure used to be horizontally organised, but now, with
the dominance of huge multinationals, it is much more vertically
The inventor of the web
talks about the Internet:
The Internet ('Net) is a network of networks. Basically
it is made from computers and cables. What Vint Cerf
and Bob Khan did was to figure out how this could
be used to send around little "packets" of
information. As Vint points out, a packet is a bit
like a postcard with a simple address on it. If you
put the right address on a packet, and gave it to
any computer which is connected as part of the Net,
each computer would figure out which cable to send
it down next so that it would get to its destination.
That's what the Internet does. It delivers packets
- anywhere in the world, normally well under a second.
Lots of different sort of programs use the Internet:
electronic mail, for example, was around long before
the global hypertext system I invented and called
the World Wide Web ('Web). Now, videoconferencing
and streamed audio channels are among other things
which, like the Web, encode information in different
ways and use different languages between computers
("protocols") to do provide a service.
The Web is an abstract (imaginary) space of information.
On the Net, you find computers -- on the Web, you
find document, sounds, videos,.... information. On
the Net, the connections are cables between computers;
on the Web, connections are hypertext links. The
Web exists because of programs which communicate
between computers on the Net. The Web could not be
without the Net. The Web made the net useful because
people are really interested in information (not
to mention knowledge and wisdom!) and don't really
want to have know about computers and cables.
OCD, World Bank
P, Vertical Relations and Connectivity in the Internet', in
Communications and Strategies, 47, 2002, pp87-101