Transcript e-Commerce by David Whiteley

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Chapter 13: The Internet
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The Internet
 ‘The web is a big place, and tens of thousands of
people have put hundreds of thousands of hours
into making it enjoyable. The vast majority of them
haven’t made any money from their work yet, and
many did it for the joy of starting something new.’
(Hoffman, 1995)
electronic
commerce
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strategy
technologies
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applications
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electronic
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The Internet
 The Internet is a strange phenomenon:
 It had its origins as a military project in 1969;
 It was adopted by the research and academic
community;
 Became the tool (or toy) of computer nerds
around the world;
and then:
 it became the engine that, it is claimed, is to
propel the world into the information age and the
twenty-first century.
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electronic
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strategy
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The Internet
 The Internet is an interesting phenomenon:
 Nobody owns it.
 Technically it is defined by its communications
protocol:
• Transmission Control Protocol/Internet
Protocol (TCP/IP).
 At another level it is defined by:
• The people who use it – individuals,
institutions and companies that make
information available, send messages,
access web sites and, in the case of eCommerce, buy and sell.
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electronic
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The development of the Internet (1)
 The origins of the Internet are commonly traced
back to a US military project, the ARPAnet:
 Commissioned in 1969.
 Explored packet switching technology (to ensure
resilience in the case of attack).
 Further early developments:
 CSNet (Computer Science Network) – 1981.
 Military split from the ARPAnet – 1983.
 JANET, Joint Academic Network (UK – 1984).
 NSFNet, National Science Foundation (USA –
1986).
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electronic
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The development of the Internet (2)
 The TCP/IP protocol was established in 1982:
 Introduced on the ARPAnet in 1983.
 Application protocols used in TCP/IP include:
• File transfer system (FTP),
• e-mail protocol (SMTP),
• Remote login facility (Telnet).
 Nodes on network identified by IP Address.
 The World Wide Web can be traced back to 1989:
 Initially developed CERN.
 Later Mosaic was developed by NCSA (1993).
 Netscape was started in 1994.
 Microsoft Internet Explorer was issues some
time later.
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electronic
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The development of the Internet (3)
 Other developments:
 Server software e.g. Apache.
 Common Gateway Interface (CGI)
 e.g. Perl programs.
 Web Programming, e.g. using JAVA, PHP, .NET
 Size of the web:
 1994 – aprox 500 web sites.
 1995 – nearly 10,000 sites
 and it grows and grows.
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electronic
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TCP/IP (1)
 Transmission Control Protocol/Internet Protocol –
TCP/IP.
 packet switching protocol:
• Messages are split up into segments
(packets) with:
– Source and destination addresses
– A package sequence number
– Other header and trailer information
 The route a packet takes through the network is
determined within the network
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electronic
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TCP/IP (2)
 Transmission Control Protocol/Internet Protocol – TCP/IP.
 TCP provides the transport protocol.
 IP provides the routing mechanism.
 IP addresses have this form 192.9.1.20.
 Used for the sending network (netid)
and the destination computer (hostid)
 Port number for the application, e.g. 80 for the WWW.
 The TCP/IP protocol stack has five layers:
• Application Layer
• Transport Layer
• Network Layer
• Data Link Layer
• Physical Layer
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TCP/IP – Application Layer
 The application is the program that initiates the
transfer (user’s own program, application package
or TCP/IP applications)
 FTP
 SMTP
 Telnet
File Transfer Protocol:
Simple Mail Transfer Protocol:
Remote login facility.
 The message, IP address and port number, are
passed to the transport layer.
 IP Address can be retrieved from the DNS (Domain
Name System)/WINS (Windows Internet Name
System).
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TCP/IP – Transport Layer
 TCP establishes a logical connection with the
receiving computer and determines the size of the
segments to be sent.
 TCP then divides up the message into segments
and attaches a header specifying:
 The source port
 The destination port
 Segment sequence number
 UDP is an alternative to TCP that is used for realtime audio or video.
 The segments and IP addresses are passed to the
network layer.
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TCP/IP – Network Layer
 Responsible for routing the packet from source
station to its final destination station, specified by
the MAC address.
 If the MAC address is not already available then:
 An ARP (Address Resolution Protocol) request
is broadcast to the network
 The machine with that IP address responds with
its MAC address.
 The Network Layer may fragment the segments
from the Transport Layer into smaller packets.
 Output packets (referred to as datagrams) are
passed to the datalink layer.
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TCP/IP – Data Link Layer
 Interface with the network to be used, e.g. Ethernet,
or X25.
 The network protocol will typically add its own
header (Nh) and trailer (Nt) that incorporate the
MAC address.
 The packet is then passed onto the medium, the
physical network layer.
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TCP/IP – Physical Layer
 The cables used for transmission.
electronic
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strategy
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applications
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electronic
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TCP/IP Protocol
Application Layer
FTP, SMTP, Telnet
or application,
DNS / WINS
server
IP address
port number
data message
Transport Layer
(TCP or UDP)
IP address
TCP head data packet
Network Layer
Target
ARP’d
IP
MAC Addr
IP head
TCP head datagram
Data Link Layer
Nh IP head
Ethernet, etc.
TCP head datagram
Nt
Physical Layer
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electronic
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Internet Components
 Client
 World Wide Web
 e-Mail
 Internet Service Provider
 Server
 Web Server
 Mail Server
 Intranets
 Extranets
 Webmaster
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electronic
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Governance of the Internet
 Co-ordination and development of the Internet is
provided by a number of voluntary committees.
 These include:
 Internet Society
 Internet Engineering Task Force
 Internet Research Task Force
 The whole arrangement works well.
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electronic
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Uses of the Internet
 Personal Messaging (e-Mail)
 Data Interchange (EDI)
 Teleworking
 Distance Education
 Entertainment
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Internet Age Systems
 Seddon (1997) suggested that the evolution of information
systems can be divided into periods of 20 years as follows:
1955–1974 The Electronic Data Processing (EDP) era.
1975–1994 The Management Information Systems (MIS) era.
1995–
The Internet era.
 EDP – essentially batch – controlled by the DP professionals –
used at the ‘organisational level’.
electronic
commerce  MIS – utilises transaction processing (TP) and databases –
enabled access to business data throughout the organisation.
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 The Internet era systems – enables BtoB and BtoC systems.
and
applications
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Internet Age Systems
Electronic Data
Processing (EDP)
Management Information
Systems (MIS)
Internet Era
Syetems
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Chapter 13 – Exercise 1
 Explain packet switching – how does packet
switching differ from a switched network
(i.e. a dialled call)?
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Chapter 13 – Exercise 2
 Draw a simple diagram of the hardware, network
and software facilities utilised when an e-Shop is
accessed from a home PC.
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Chapter 13 – Exercise 3
 Consider your college, university or place of work
and suggest what uses/information would be
appropriate to an intranet, an extranet and the
Internet.
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Chapter 13 – Exercise 4
 The chapter lists some of the facilities available on
the web (e-Commerce, e-Mail, etc).
Add to the list and suggest business (as opposed to
personal) uses for each of the facilities listed.
electronic
commerce
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strategy
technologies
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