basics of computers

1. Internetworking
• Internetworking involves connecting two or
more distinct computer networks or network
segments via a common routing technology.
The result is called an internetwork (often
shortened to internet).
• The most notable example of internetworking
is the Internet (capitalized), a network of
networks based on many underlying hardware
technologies, but unified by an
internetworking protocol standard, called the
Internet Protocol Suite (TCP/IP).

2. • An internetwork is a collection of individual
networks, connected by intermediate
networking devices, that functions as a
single large network. Internetworking refers
to the industry, products, and procedures
that meet the challenge of creating and
administering internetworks. Figure 1-1
illustrates some different kinds of network
technologies that can be interconnected by
routers and other networking devices to
create an internetwork.

4. Basics of Internetworking
• Gives an illusion of a single (direct link)
network
• Built on a set of distributed heterogeneous
networks
• Abstraction typically supported by
software

5. Internetwork properties
• Supports heterogeneity: Hardware, OS,
network type, and
• topology independent
• Scales to global connectivity

18. Internet Protocol (IP)
• Network- level protocol for the Internet
• Operates on all hosts and routers
• Protocol stack has an “hourglass” shape

19. Protocols
• Protocols are sets of rules that define how
different parts of a network interact to allow
devices to communicate with one another. They
provide a ‘common language’ to allow different
vendors’ computer equipment to communicate
with each other. The different devices can use
completely different software, provided that each
device’s software can agree on the meaning of
the data. Protocols can describe low-level details
of machine-to-machine interfaces (like the order
in which bits and bytes are sent across the wire)
or high-level exchanges between allocation
programs (the way in which two programs
transfer a file across the Internet).

20. Internet Protocols
• The Internet Protocol defines a
connectionless data delivery service
between networked devices. Packets of
data are sent as datagrams across the
network. Large packets may be broken
into several datagrams which are each
sent individually across the network. Each
datagram carries its full destination
address and control information.

23. • To route packets in an internetwork, IP
uses a dynamic routing protocol called the
Routing Information Protocol (RIP). Today
RIP is the most commonly used Interior
Gateway Protocol (IGP) in theInternet
community. The primary function of RIP is
to inform routers about other routers on
the network.

24. Serial Line Internet Protocol
(SLIP)
• SLIP transmits IP packets over serial
lines. If using SLIP, the network must use
TCP/IP as its primary means of
communication between resources. A
SLIP connection only allows one
communication application to be active at
any one time.

25. Simple Mail Transport Protocol
(SMTP)
• SMTP transfers e-mail from one server to
another across the network.
• End users must use the Post Office
Protocol (POP) to transfer the
• messages to their machines.

26. File Transfer Protocol (FTP)
• FTP provides a way to move files between
computer systems. It is a widely used way
of transferring files to and from the Internet
and is relatively simple to operate.

27. WWW Structure
• Clients use browser application to send URIs via HTTP to
servers requesting a Web page
• Web pages constructed using HTML (or other markup
language) and consist of text, graphics, sounds plus
embedded files
• Servers (or caches) respond with requested Web page
– Or with error message
• Client’s browser renders Web page returned by server
– Page is written using Hyper Text Markup Language (HTML)
– Displaying text, graphics and sound in browser
– Writing data as well
• The entire system runs over standard networking protocols
(TCP/IP, DNS,…)

28. HTTP Basics
• Protocol for client/server communication
– The heart of the Web
– Very simple request/response protocol
• Client sends request message, server replies with response
message
– Stateless
– Relies on URI naming mechanism

29. WWW Pages and Browsing
• A web browser is a software application which enables
a user to display and interact with text, images, videos,
music, games and other information typically located on
a Web page at a website on the World Wide Web or a
local area network. Text and images on a Web page can
contain hyperlinks to other Web pages at the same or
different website. Web browsers allow a user to quickly
and easily access information provided on many Web
pages at many websites by traversing these links. Web
browsers format HTML information for display, so the
appearance of a Web page may differ between
browsers.

30. Security
• When a computer connects to a network
and begins communicating with others, it
is taking a risk. Internet security involves
the protection of a computers internet
account and files from intrusion of an
outside user. Basic security measures
involve protection by well selected
passwords, change of file permissions and
back up of computers data.

31. • A network security policy is a generic document that
outlines rules for computer network access, determines
how policies are enforced and lays out some of the basic
architecture of the company security/ network security
environment. The document itself is usually several
pages long and written by a committee. A security policy
goes far beyond the simple idea of "keep the bad guys
out". It's a very complex document, meant to govern data
access, web-browsing habits, use of passwords and
encryption, email attachments and more. It specifies
these rules for individuals or groups of individuals
throughout the company.
• Security policy should keep the malicious users out and
also exert control over potential risky users within your
organization. The first step in creating a policy is to
understand what information and services are available
(and to which users), what the potential is for damage
and whether any protection is already in place to prevent
misuse.

32. • In addition, the security policy should dictate a
hierarchy of access permissions; that is, grant
users access only to what is necessary for the
completion of their work.
• While writing the security document can be a
major undertaking, a good start can be achieved
by using a template. National Institute for
Standards and Technology provides a security-
policy guideline.
• The policies could be expressed as a set of
instructions that could be understood by special
purpose network hardware dedicated for
securing the network.

37. E- Commerce
• UK Government
“E-Commerce is the exchange of information across
electronic networks at any stage in the supply chain
whether within an organisation , between businesses,
between business & consumers, or between public
and private sectors whether paid or unpaid”
• Zwass (1998)
“ E-Commerce is the sharing of business information ,
maintaining business relationships & conducting
business transactions by means of telecommunications
networks”

38. E-Business & E-Commerce
• IBM’s Definition of E-Business
– “The transformation of key business processes
through the use of internet technologies”
• R. Kalakota (1999)
“E-Commerce is buying & selling activities over digital
media”
– E-Business – encompasses e-commerce &
“includes the front & back-office applications that form
the engine for modern business. Its not just about e-
commerce transactions, it’s about redefining old
business models with the aid of technology to
maximise customer value”

40. Rules of E-Business
• Rule 1 – Technology is no longer an afterthought in forming
business strategy – It’s the actual cause & driver
• Whilst computers didn’t fundamentally alter business foundations – the
internet does.
• Rule 2 - Ability to streamline, structure, influence and control the
flow of information is more powerful & cost-effective than moving &
manufacturing physical products
• intangibles are becoming more valuable - branding, customer relationship,
integration
• Rule 3 – Inability to overthrow the dominant, outdated business
design often leads to failure.
• move to outsourcing & high levels of internal integration
• Rule 4 – Goal of new business design is to create flexible
outsourcing alliances between companies that not only off load
costs but also make customers ecstatic.
• Speed, Convenience, Personalisation, Price

41. • Rule 5 – e-Commerce is enabling companies to listen to their
customers and become either the cheapest, the most
familiar, or the best
• Wal-Mart, McDonalds, Coca–Cola, Amex – What have you done for me ?
• Rule 6 – Use technology to innovate, entertain, and enhance the
entire transaction process from selection to receipt & service
• Amazon,.
• Rule 7 – Future e-business design models will increasingly use
reconfigurable e-business community models to best meet
customer’s needs.
• Integrated customer centric business models – supporting complex business
designs – IF, Cahoot, Amazon, E-Trade
• Rule 8 – Management’s task is to align business strategies,
processes and applications , fast, right and all at once – very
difficult

42. Electronic commerce
• To many people the term electronic commerce,
– often shortened to e-commerce, is equivalent
– to shopping on the web.
• The term electronic business is sometimes used
– to capture the broader notion of e-commerce.
• In this course, we will use e-commerce in its
– broadest sense. It encompasses both web
– shopping and other business conducted
– electronically.

43. Electronic commerce
• Banks have used electronic funds transfers
– (EFTs), also called wire transfers, for decades.
• Businesses have been engaging in electronic
– data interchange for years. EDI occurs when
– one business transmits computer readable data
– in a standard format to another business.

44. • We will define e-commerce as the use of electronic
• data transmission to implement or enhance any
• business activity.
• Example (Figure 1-4): A buyer sends an electronic
• purchase order to a seller. The seller then sends an
• electronic invoice back to the buyer.
• When used appropriately, electronic transmission
• can save both time and money.

45. Impact of e-commerce
• E-commerce is changing the way
traditional
• commerce is conducted:
• Technology can help throughout the
process
– including promotion, searching, selecting,
– negotiating, delivery, and support.
• The value chain is being reconfigured.

46. Advantages of e-commerce
• For the seller:
• Increases sales/decreases cost
• Makes promotion easier for smaller firms
• Can be used to reach narrow market segments
• For the buyer:
• Makes it easier to obtain competitive bids
• Provides a wider range of choices
• Provides an easy way to customize the level of
– detail in the information obtained

47. Advantages of e-commerce
• In general:
• Increases the speed and accuracy with which
– businesses can exchange information
• Electronic payments (tax refunds, paychecks,
– etc.) cost less to issue and are more secure
• Can make products and services available in
– remote areas
• Enables people to work from home, providing
– scheduling flexibility

48. Advantages of e-commerce
• Some business processes are not suited to
– e-commerce, even with improvements in
– technology
• Many products and services require a critical
– mass of potential buyers (e.g. online grocers)
• Costs and returns on e-commerce can be
– difficult to quantify and estimate
• Cultural impediments: People are reluctant to
– change in order to integrate new technology
• The legal environment is uncertain: Courts and
– legislators are trying to catch up

49. Disadvantages of e-commerce
• Some business processes are not suited to
– e-commerce, even with improvements in
– technology
• Many products and services require a critical
– mass of potential buyers (e.g. online grocers)
• Costs and returns on e-commerce can be
– difficult to quantify and estimate
• Cultural impediments: People are reluctant to
– change in order to integrate new technology
• The legal environment is uncertain: Courts and
– legislators are trying to catch up

50. E-Commerce Market Place
Electronic Commerce is part of an evolving approach to
business that could eventually involve the application of
Information & Communication Technology (ICT) to the
Product and Distribution of goods and services on a
global scale.
Electronic Commerce can be used to support fully
automated transactions, but, for immediate future at
least, it also encompasses many partially automated
transactions involving human and physical interfaces and
intermediaries of various kinds.

51. Participating Groups in E-Commerce
• Electronic Commerce can occur within
and between three basic participant
groups-
– Business
– Government
– Individuals
At present and by a large margin, most e-
commerce occurs on a B-to_B level.

52. Economic Potential of E-Commerce
• E-Commerce is the marriage between a rapidly
evolving technical environments and an
increasingly pervasive set of ideas as to how
markets should function.
• However markets involve complex interaction
between specific business/ organizational
factors and general economic, social and
political factors.
• At this point in time, Economic Potential of E-
commerce can only be evaluated against a
backdrop of rapid change on all of these fronts.

53. Forces behind E-Commerce
• Internet Acceptance is the Driving Force
Behind e-Commerce
• Increased Awareness
• Significant improvements in Infrastructure
• Increased Competition among the
organization and thus in search of the
technologies and ways to take the edge over
others.
• Customer Oriented markets

54. E-Commerce Framework

55. E-Commerce Framework