Title: The growth and development of the Internet'
1U10988 The Economics of the Internet (ENET)
- Lecture 2
- The growth and development of the Internet.
- Internet growth statistics, access and use.
- Infrastructure, institutions and protocols.
2Todays objectives
- to inform you about the important stages in the
development of the Internet, the applications
that run on it and the associated protocols - to familiarise you with some key points about the
technical infrastructure of the Internet - to highlight the role of some key people and
organisations - to look at the growth of the Internet and
consider factors (especially economic ones) that
can account for this growth
3Reading
- Rohlfs (2001) book - especially Chapter 13
- Rohlfs (2001) article available online
- Greenstein and Prince (2005)
- Tanenbaum - especially Chapter 1
- the material on the ENET website for week 2 and
the links from it
4Follow up work for the week
- Practical 2
- 1 explanation of some key terms and consideration
of their relevance to our understanding of the
growth and development of the Internet - 2 identification of the role of some key people
- 3 identification of the role of some key
organisations - 4 Internet metrics issues
5Some points from last week
- the Internet and the World Wide Web are not the
same thing - the importance of protocols - the standards or
set of rules that enable computers to communicate
with each other - the adaptable nature of the Internet and its
institutions - The importance of network externalities and
complementary bandwagon effects for the take off
of the Internet
6The Internet
- The Internet is an interconnected set of computer
networks across the globe that work together
under a common set of rules or protocols (the
TCP/IP suite). - The name Internet refers to the global seamless
interconnection of networks made possible by the
protocols devised in the 1970s, the Internet
protocols, still in use today. Vint Cerf, 1995
7Internet backbone networks, ISP etc.
8From ARPANET to Internet
1969 ARPANET - a single network with 4 nodes
(funded from US Defense budget) 1973 work began
on linking networks Internetting first
international links to UCL and Norway 1985 NSF
takes over the backbone for interlinking networks
(still government funded but by now more
academic than military) 1995 NSF funding stops -
commercial companies take over the Internet - by
then it consists of over 50,000 networks
connecting over 5 million computers
9The original ARPA network
10Internet traffic (2001) as depicted by
TeleGeography Inc.
11A more detailed depiction of Internet traffic
from TeleGeography Inc.
12http//www.telegeography.com/maps/internet/images/
europe_map_large.gif
13JANET - the Joint Academic Network in the UK
14Protocols
- A protocol is an agreement (set of rules)
between the communicating parties (peers) on how
communication is to proceed.
15The TCP/IP suite
- Q Why is it important?
- A It enables computers on different networks,
designed by different vendors, to work together
in delivering various applications e.g. e-mail,
file transfer, remote login (telnet), use of the
web etc. - TCP/IP was the key to turning the Arpanet into
the Internet.
16TCP/IP key dates
- 1964 Paul Baran (RAND Corporation) publishes
paper on packet-switching networks - 1974 Vint Cerf and Bob Kahn publish paper
describing TCP - 1978 Vint Cerf and others separate the TCP and IP
functions
17Internet applications and their protocols
- Early core applications
- File Transfer FTP (SSH is usually now preferred)
- Terminal access (remote login) Telnet
- Electronic mail (E-mail) SMTP
- Newsgroups Usenet
- The World Wide Web HTTP
- Other Internet applications include chat
systems, Videoconferencing, Video and audio
streaming, Voice over Internet, peer-to-peer
file-sharing, instant messaging etc.
18The IP address
- Every computer on the Internet has a unique IP
address - four numbers separated by dots - e.g. 198.137.240.100
- identifies the main host computer at the White
House
19Find your IP number
-
- The State University of New York at Stony Brook
provides a service whereby you can find out the
IP number of the Internet computer you are
connected to. - Why not try it? (URL on my links page).
20DNS - Domain Name System (1)
- DNS is a hierarchical domain-based naming scheme
and distributed database system for mapping host
names and e-mail destinations to IP addresses. - Domain names are easy (for humans) to remember
names for the computers on the Internet i.e.
those that have been assigned IP numbers
21DNS - Domain Name System (2)
- ICANN (Internet Corporation for Assigned Names
and Numbers) coordinates the assignment of IP
numbers and Internet domain names. -
22DNS - Domain Name System (3)
- The top level domain covers two identifiers,
separated by a dot - generic type - e.g. .com, .ed (or .co and .ac) -
recent additions include .biz and .coop - country codes - e.g. .uk, .cn, .gr, .nl, .jp
23DNS - Domain Name System (4)
-
- Sub-domains can then be created lower down the
hierarchy by those responsible for that level - e.g. userweb.port.ac.uk
24Computer networks
-
- A computer network is a collection of
autonomous but linked computers.
25Why computer networks?
- Resource sharing
- Communication
- Increased reliability
- Improved scalability
- Cost savings
26The Internet puts you in touch with resources
and people
- Access to remote information (e.g. data sources,
e-commerce, video on demand) - Person to person communication (e.g. e-mail,
videoconferencing) - synchronous and asynchronous links
27Network connections
- via
- copper wires
- cable
- fibre optics
- microwaves (radio frequency)
- communication satellites
28Network architecture
- architecture is a set of layers and protocols
- purpose of layer is to carry out services for the
higher layer in a way that is transparent to the
higher layer - layers communicate with their peers according to
known protocols - between layers there is an interface
29Design issues for layers
- layers need to
- identify senders and receivers
- have rules for communication (protocols)
- know about different available routes
- have conventions about speed
- identify and correct errors
30Size classification of networks
- Local Area Networks (LAN)
- Wide Area Networks (WAN)
- internets
- Tanenbaum also distinguishes Home Networks,
Wireless Networks and Metropolitan Area Networks
(e.g. based on cable TV)
31client-server model
32clients
- E-mail client software
- Outlook
- Groupwise
- Eudora
- also web based e-mail systems such as GMail,
Hotmail and Yahoo!
33SMTP
- Simple Mail Transport Protocol
- encodes every e-mail message as a sequence of
ASCII characters - Used to send e-mail messages from one server to
another. Messages can be retrieved with an e-mail
client using POP or IMAP protocols
The Economics of
the Internet Guy Judge, February 2006
34M IM E
- Multipurpose Internet Mail Extension
- specifies how non-text may be transmitted by SMTP
35Key dates in the evolution of the Internet -
Electronic Mail
- 1971 - Ray Tomlinson of Bolt Beranek and Newman
Inc. (BBN) invents the first e-mail program to
send messages across a distributed network - 1972 - Tomlinson adapts the program to run on
ARPANET where it is immediately taken up with
enthusiasm - 1975 - John Vittal develops MSG, the first widely
available e-mail program - 1978 the first incidence of spam!
36Ray Tomlinson
37World Wide Web (WWW)
- The World Wide Web is a collection of
- inter-linked documents and associated
- files that are made available to people
- with computers connected to the
- Internet via a special protocol called
- HTTP (HyperText Transfer protocol)
38Key dates in the evolution of the Internet -
precursors of the World Wide Web
- 1965 Ted Nelson sets up project XANADU to
establish world-wide distributed library of
information (earlier inspiration from Bush
1945) - gopher system developed at University of
Minnesota - mid 1980s - hypertext packages such as HyperCard
(1987) and Guide developed
39Key dates in the evolution of the Internet -
the World Wide Web
- 1989 - creation of the World Wide Web and HTTP at
CERN(Geneva) by Tim Berners-Lee and others - 1993 - first publicly available web browser
(MOSAIC) developed at NCSA - 1990s - new browsers (Netscape, IE) - with helper
applications and plug-ins for dealing with
graphics, video etc. - 1994 - W3C, the World Wide Web Consortium set up
(http//www.w3.org/)
40Sir Tim Berners-Lee
41remote access or terminal emulation telnet
- telnet allows you to login to other remote
computers on Internet to which you have access
rights - e.g. I used to log in to the MIMAS computer at
Manchester from Portsmouth using MS Telnet
42file transfer
- transferring files from computer to computer on
the Internet - FTP File Transfer Protocol
- first established 1971
- FTP and FTP client software (e.g.. WS_FTP32)
- anonymous FTP
- more secure protocols such as SSH are now
preferred
43Internet organisations and agencies
- No single body in overall charge, but the
following all have important roles - ICANN (Internet Corporation for Assigned names
and Numbers) manages domain names and IP
addresses - ISOC (The Internet Society)
- W3C (World Wide Web Consortium)
- We should perhaps also mention the regulators
- Ofcom (UK) and FCC (US)
44Internet organisations and the United Nations
- Many people have argued that the Internet should
not be governed by a private (US) company (ICANN)
but by a multilateral organization with
international legitimacy and democratic processes
under United Nations control like the ITU
(International Telecommunications Union) some
have suggested that the ITU should take over some
of the functions of ICANN. - The second World Summit on the Information
Society (WSIS) was held last November in Tunisia.
It received a report from the Working Group on
Internet Governance (WGIG).
45Internet metrics
- The Internet Software Consortium conducts a
semi-annual survey of the number of Internet
hosts (see next slide). - But Zook (2000) cautions us about using this
measure uncritically
46(No Transcript)
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49Source OECD
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51Internet Access Highest in London and South East
Adults who have used the Internet in the last 3
months by Government Office Region and GB country
Source National Statistics http//www.statistics.
gov.uk/CCI/nugget.asp?ID914
52Internet metrics
- There are also problems in counting the number of
people online, or the number of web pages (see my
links page for more details). - But despite these concerns there is no doubt that
there has been phenomenal growth in the Internet
and its use - particularly since around 1994 -
WHY?
53Reasons for the rapid growth of the Internet and
its use
- Network externalities - the value of the Internet
to any one user is an increasing function of the
total number of users Rohlfs - Complementary bandwagon effects - part of the
value of the Internet derives from the
availability of complementary products, services
and applications (e-mail, web browsers, news and
information services etc..) As the network
expands there are increased incentives for the
suppliers of complementary products Clements
(2004) calls this an indirect network
externality - E-Commerce
- Despite the hype and the bursting of the dot.com
bubble - the Internet continues to grow and expand into
new areas
54Metcalfes law or DeLongs law
- Metcalfes Law - the value of the Internet to
any one user increases as the square of the total
number of users - DeLongs Law - the most important and cheapest
links are established first and it becomes
increasingly costly to connect the last few users
55E-commerce and e-banking drivers
- Lower transactions costs - automated systems can
vastly reduce transactions costs - Global reach - more customers are within reach
(especially for information products that can be
delivered as well as ordered and paid for over
the Internet
56Reduction in transactions costs Cost to bank -
typical US funds transfer transaction ()
Source PIU Report on e-commerce
57Possible essay question
- To what extent can the phenomenal growth of the
Internet in the last decade be explained by
economic factors? Use relevant economic concepts
and models to support your arguments. - Hints You would need to include the following
concepts - (i) network externalities (ii) complementary
bandwagon effects (iii) critical mass (iv)
interlinking (v) common standards and protocols .