1. ASSIGNMENT ON: INTRODUCTION TO INTERNET
1) DEFINITION OF INTERNET & USES OF THE INTERNET
Internet:
Internet is a collection of Networks connected by internetworking devices such as
router or gateway.
The internet has its root in the ARPANET System of the US Department of Defense.
Internet can be defined as a network of networks, which share a common mechanism
for addressing computers and a common set of communication protocols for
communications between two computers on the network.
Uses of the Internet:
The world wide scope of the internet makes it perhaps, the single most valuable tool
for use in many significant ways by both non-profit and commercial organizations.
Some important uses of the Internet are listed below:
I. Online Communication:
The E-mail service on the internet is extensively used today by computer users
around the world to communicate with each other.
II. Software Sharing:
The internet provides access to a large number of shareware software
development tools and utilities. The Free Software Foundations also provides a
wealth of GNU software tools on the internet, that can be downloaded free of
charge.
III. Exchange of Views on Topics of Common Interest:
The internet has a number of news groups. Each news groups allows a group of
users to exchange their views on some topics of common interest.
IV. Posting of Information of General Interest:
It is often used as a large electronic bulletin board on which information of
general interest can be posted to bring it to the attention of interested users.
V. Product Promotion:
Several commercial organizations are effectively using the internet services
promoting their products. They mainly focused on information about corporate
happenings, product announcements, recent strategy etc.
VI. Customer Support:
Many organizations are also using the internet to provide timely customer
support.

2. VII. Online Journals & Magazines:
The internet now has literally thousands of electronic subscriptions, which can be
found both for free and low cost.
VIII. World-wide Video Conferencing:
World wide video conferencing is an emerging service on the internet which
allows a group of users located around the globe to talk and interact with each
other.
IX. Online Degree & Courses:
Recently internet uses as a medium of taking online degree and take part on
different courses.
2) SOME SHORT NOTES:
 WWW (World Wide Web)
The World Wide Web (WWW) is the most popular and promising method of
accessing the internet. WWW is a depositor of information linked together from
points all over the world. Tim Burners Lee introduced it first. World first website
is info.cern.ch.
 Hypertext:
Hypertext or hyper is an information containing text that is linked to other
documents through a point. An effectively designed hypertext document can
help users rapidly locate the desired type of information on the internet.
 Webpage:
Webpage is a unit of hypertext or hyper media available on the web. WebPages
are created using a special language called Hypertext Markup Language.
 HTTP:
HyperText Transfer Protocol (HTTP) is an application service for retrieving a
web document. Any computer on the internet, which uses the HTTP protocol, is
called a web server.
 File Transfer Protocol:
File Transfer Protocol (FTP) is TCP/IP an application layer protocol that transfer
files between two sites.
 DNS:
Domain Name System or DNS is TCP/IP an application layer protocol that
transfer file between two sites.

3.  URL:
Uniform Resource Locator (URL) is a string character that identifies a page on
the WWW. It is an addressing scheme used by WWW browsers to locate sites
on the internet.
Protocol Host Port Path
:// : /
Example: http://www.wub.edu.bd/about.wub
 Subscriber Identity Module:
Subscriber Identity Module (SIM) is a portable memory chip used in models of
cellular phone.
 Telnet:
Terminal Network that is Telnet is TCP/IP application layer protocol that transfer
files between two sites.
3) ELECTRONIC MAIL & ITS ADVANTAGES:
Electronic mail is a system for exchanging data through a computer network. It
allows an internet user to send a mail to another internet user in any part of the
world in a near real time manner.
All internet users have an e-mail address that identifies an individual user of an e-
mail system and has a logical mailbox. When sending a mail to another user, the
sender specifies the e-mail address of the receiver. Then the receiver extracts the
mail from the mailbox and reads it’s at his convenient time.
Advantages:
With e-mail service, the internet has proved to be a rapid and productive
communication tool for millions of users. As compared to paper mail, telephone or
fax, e-mail is preferred by many because of its following advantages:
I) It is faster than paper mail;
II) Unlike the telephone, the persons communicating need not
be available at the same time;
III) E-mail documents can be stored in a computer memory and
can be easily edited by using editing programs.

4. 4) SERVER & CLIENT
Server:
A server is a computer or device on a network that manages network resources. It
may store application software, database and data files for the network. In this
case, it is usual to have one process, which owns the resource or service and is in
charge of managing it. This process accepts requests from other process, which
want to use resource or service. The process that owns the resource and does this
management is called server process, the computer on which the server process
runs is called a server computer.
Client:
A server or network server is a control computer that holds collection of data and
programs for many PCs, workstation and other computers which are called clients.
The entire network is called Client-Server network.
Types of Servers:
Several types of servers are described below:
I. File Server: File server provides a central storage facility to store files of several
users on the network.
II. Database Server: Database server manages a centralized database and
enables several users on the network to have shared access to the same
database.
III. Print Server: Print server manages one or more printers and accepts the process
the print requests from any user in the network.
IV. Name Server: Name Server translates names into network address enabling
different computers on the network to communicate with each other.
Some other servers are:
V. Application Server: Application server occupy a large chunk of computing
territory between database servers and the end user, and they often connect the
two.
VI. Audio/Video Server: Audio-video server bring multimedia capabilities to Web
sites by enabling them to broadcast streaming multimedia content.

5. VII. Chat Server: Chat server enables a large number of users to exchange
information in an environment similar to internet news groups that offer real tome
discussion capabilities.
VIII. Fax Server: A fax server is an ideal solution for organizations looking to reduce
incoming and outgoing telephone resources but that need to fax actual documents.
IX. FTP Servers: File Transfer Protocol makes it possible to move one or more files
securely between computers while providing file securely between computers while
providing file security and organization as well as transfer control.
X. Mail Server: Mail server move and store mail over corporate networks via LAN
and WAN and across the Internet.
XI. Telnet Server: A telnet server enables users to log on to a host computer and
perform tasks as if they’re working on the remote computer itself.
5) DEFINITION OF ROUTER & ITS CLASSIFICATION:
Router:
Router are designed to transmit data from one location to another via network, the
router is responsible for doing the most work to ensure the data delivered.
Types of Router:
A) Wireless Router:
Wireless routers have become popular in recent years because they allow
connecting to a network from anywhere in home or office and don’t have the
large mess of cables and wire which are associated with traditional wired
network.
B) Broadband Router:
Broadband router is responsible for taking the features of a standard
network switch and combining them with a DHCP Server.
C) Mobile Router:
Mobile router, which doesn’t need any wireless links, one of its biggest
advantages is that it can work with virtually any type of interface. It can be
used Fast Ethernet and Ethernet connection.

6. 6) DIFFERENT TYPES OF TRANSMISSION MEDIUM:
I. Unguided Media
II. Guided Media
I. Unguided Media:
A. Microwave System:
Microwave System transmits voice and data through the atmosphere
as high frequency radio waves. However at microwave frequencies, the
electromagnetic waves cannot bend or pass obstacles like hill. Thus it is
necessary to be in a line of sight.
B. Satellites:
Satellite system is basically a microwave relay station placed in orbit
around the earth. These satellites are launched by either rockets or space
shuttle. Traditionally the orbit has been 22300 miles above the earth.
Solar Cells
Concentrated Beam Antenna
Transmission Antenna
Control Antenna

7. Fig: Satellite
Advantages:
 It can be used for data transmission between any two randomly
chosen points in an area.
 The costs are independent of the distance
 A satellite having many transponders has enormous data
communication capability.
Disadvantages:
 The initial cost is very high.
 Special security measures are needed to prevent unauthorized
tampering of information.
II. Guided Media:
A) Twisted Pair Cable:
A twisted pair cable consists of two bunches of thin copper wires, each
bunch enclosed separately in a plastic insulation, then twisted around each
other to reduce information by adjacent wires. These cables are commonly
used in local telephone communication and short distance digital data
transmission.
Fig: Twisted Pair Cable
B) Coaxial Cable:
Coaxial cable consists of conducting core, insulating material, a second
conducting sheath. This is able to transmit data at high rates. The signal is transmitted by
the inner copper wire and is electrically shielded by the outer metal sleeve. They are
extensively used in long distance telephone lines as cables for cable TV.
Insulator

8. Plastic Cover Outer Conductor Inner Conductor
Fig: Coaxial Cable
C) Optical Fibers:
Optic fiber is a thin thread of glass or other transparent material to carry light
beams or transmits pulsating beams of light. Light travels much faster than electricity. It
can transmit data at much higher speed than copper wires or coaxial cables and also with
no significant loss of intensity over very long distance.
Sender Receiver
Cladding
Fig: Optical Fiber
Advantages:
 Very high bandwidth
 Protection against electromagnetic interference
 More secured as they can not be tapped easily
 Light weight and no corrosion
Disadvantages:
 It is difficult to align and join two fiber optic
 They can not have sharp beams.
7) DATA TRANSMISSION MODE:
There are three ways or modes of transmitting data from one point to another.
They are: I) Simplex;
II) Half duplex;
III) Full duplex.

9. I. Simplex: If transmission is simplex, communication can take place in only
one direction. Devices connected to such a circuit are either a send only or
receive only device.
One direction only
Sender Receiver
II. Half Duplex: A half duplex system can transmit data in both directions, but
only in one direction at a time. Half duplex line can alternately send and
receive data. This is the most common type of transmission for voice
communication because only one person is supposed to speak at a time.
Receiver
--------
Sender ------------------------------
In both direction but not at the same time
III. Full Duplex: Full duplex system allows information to flow simultaneously
in both directions in the transmission path. Use of a full duplex line improves
efficiency, because the line turn around time required in a half duplex
arrangement is eliminated.
Receiver
--------
Sender
Both directions at the same time
8) ASYNCHRONOUS & SYNCHRONOUS TRANSMISSION:
Data transmission on a communication line is normally carried out in two different
modes - asynchronous and synchronous.
Asynchronous Transmission: Here data is sent one byte at a time. Each string of
bits making up the byte is bracketed or marked off, with special control bits. That is
a Start bit represents the beginning of a character and stop bit represents its end. It
is well suited to many keyboard type terminals. The advantage of this method is
that it does not require any local storage at the terminal o the computer.
0 Character 0 1 0 Character 1 1 Receiver
Sender

10. Fig: Asynchronous Transmission
Synchronous Transmission: Synchronous using start and stops bits to send
data in blocks. Start and stop bits pattern called Sync bytes, are transmitted at the
beginning and the end of the blocks. The number of characters in a block may be
variable, and may consist of hundreds of characters. It is well suited to remote
communication between computer and such devices as buffered terminals and
printers.
Start Sync Characte Characte Error Stop Receiver
Bytes r r Check Sync Sender
Bytes bytes
Fig: Synchronous Transmission
9) DIFFERENT TYPES OF SWITCHING TECHNIQUES:
I. Packet Switching:
A packet is a maximum-fixed-length block of data for transmission. The packet
also contains instructions about its destination.
Electronic message are divided into packets for transmission over a Wide Area
Network (WAN) to their destination, through the most expedient routes is packet
switching.
Advantages:
 Handle high volume traffic in a network.
 Sending message over long distance.
 Packets are of small and fixed size.

11.  The method is fast enough for interactive / real time applications
Uses:
 Telnet
 Data sending
 Tymnet
 AT & T’s Accunet.
II. Circuit Switching:
Circuit switching by which the transmitter has full use of the circuit until the data
has been transmitted and the circuit is transmitted.
Advantages:
 Once the circuit is established, data is transmitted with no delay other
than the propagation delay, which is negligible.
 It is suitable for low-speed communication between a terminal and a
computer, because the method is simple and requires no special
facilities.
 The method is suitable for long continuous transmissions.
Uses:
 Telephone Company
 Voice Networks
 Data and Real-time voice and video.
10) MULTIPLEXING:
Multiplexing is the transmission of multiple signals over a single communication line
or channel. That is, it is the method of dividing a physical channel into multiple
logical channels to enable a number of independent signals to be simultaneously
transmitted.
3 devices of multiplexing are:

12. i. Multiplexers: Multiplexers is a device that manages several low speed
transmissions into high speed transmission. A multiplexer takes several
data communication line or signals, and converts them into one data
communication line or signal at the sending location.
ii. Concentrators: It is a piece of hardware that enables several devices to
share a single communication line. The advantage of using a
concentrator is that devices of varying speeds and types are connected to
the concentrator, which in turn is connected to the host computer by high-
speed lines.
iii. Front-End Processor: It is a smaller computer that is connected to a
large computer and assists with communication functions.
First High speed line Second
Multiplexer Multiplexer
Mainframe
Work stations
Fig: Multiplexing
11) NETWORK TOPOLOGIES:
The physical layout or shape of a network is called network topology. It determines
the data paths, which may be used between any pair of nodes in the network. The
four major topologies are star topology, bus topology, ring topology and hybrid
topology.

13.  Star Topology: Star topology is a star network. All computers and other
communication devices are connected to a control hub such as a file
server or host computer, which centrally controls communication between
any two other computers by establishing a logical path between them. The
main advantage is if any of the local computers fails, the remaining portion
of the network is unaffected.
Advantages
Easy to setup
One cable can not crash network
Disadvantages
One hub crashing downs entire network
Uses lots of cable
Fig: A star topology.
 Ring Topology: Ring topology is a ring network where all computers
and other communications devices are connected in a communication
loop. Electronic message are passed around the ring in one direction. The
only decision a node ahs to take is whether the data is for its own use. If it
is addressed to it, it utilizes it. Otherwise, it merely passes it on to the next
node.
Advantages
Time to send data is known
No data collisions
Disadvantages
Slow
Lots of cable

14. C
E
A
B P
C D
 Bus Topology: In a bus network all communication devices are
connected to a common cable called a bus.
Bus line
Advantages:
a) It helps in reducing the number of physical lines.
b) The failure of a computer does not affect the communication.
c) Addition of new computers to the network is easy.
Disadvantages:
a) All computers in the network must have good communication
and decision making capability.
b) If the communication line fails, the entire system breaks down.
 Hybrid Topology: Hybrid topology is a combination of two or more
different network topologies. The exact configuration of the network
depends on the needs and the overall organization structure of the
company involved.
R
ou
t
e
r

15. Fig: Hybrid Topology
 Mesh Topology: Another kind of topology is Mesh topology. A network
configuration in which each device has a dedicated point to point link to
every other device.
Advantage
Data will always be delivered.
Disadvantages
Lots of cable.
Hard to setup.
Fig: Mesh Topology

16. 12) DEFINITION OF OSI MODEL & ITS DIFFERENT LAYERS:
Open System Interconnection or OSI is a set of protocols that allows any two
different systems to communicate regardless of their underlying architecture
without changing hardware and software.
There are seven layers involving with OSI Model.
7. Application Layer
6. Presentation Layer
5. Session Layer
4. Transport Layer
3. Network Layer
2. Data Link Layer
1. Physical Layer
I. Physical Layer: Physical Layer is responsible for movements of individual
bits from one hop to next. It also performs:
 Representation of bit;
 Data rate;
 Synchronization of bit;
 Line configuration;
 Physical topology;
 Transmission mode.

17. II. Data Link Layer: Data link layer to organize bits into frames and provide
hop to hop delivery. It performs the following operations:
 Framing of bits;
 Physical addressing;
 Flow controlling;
 Error controlling;
 Access controlling.
III. Network Layer: Network layer to move packets from source to destination
and providing internetworking.
 Logical address generating;
 Routing.
IV. Transport Layer: Transport layer to provide reliable process of message
delivery and error recovery. It also performs:
 Service point addressing;
 Connection control;
 Flow and error control.
V. Session Layer: Session layer to establish manage and terminate session.
It accomplish the following job:
 Dialog control;
 Synchronization.
VI. Presentation Layer: it is responsible for translation, compression and
encryption.
VII. Application Layer: Application Layer to allow access to network
resources that responsible for providing services to the user.
 File transfer access and management
 Mail services;
 Directory services.
13) DEFINITION & COMPONENTS OF INFORMATION SYSTEM:

18. Information is the data placed in meaningful and useful context for an end user.
Information obtained by processing data into meaningful and useful context and
form.
Information System is an organized set of components for collecting, transmitting,
storing and processing data in order to deliver information.
Data Processing Information
Fig Information System
$35000 12 units Sales Persons: J. Jones
$10000 15 units Processing Data States Territory: Western Region
J. Jones Current Sale: 37 unit= $60000
Western Region
Components of information System:
End User and IS specialized
Data and knowledge base
Software Programs and procedure
Hardware Machines and Media
Communication and Network Support
14) CLASSIFICATION OF INFORMATION SYSTEM:
Transactions
Processing System
Operations Supports
System
Process Control System
Office Automation
System

19. Information
System
Management
Information System
Management
Support System Decision Support
System
Executive Information
System
15) LAN, MAN & WAN:
LAN:
A Local Area Network is usually privately owned and links the devices in a single
office, building or campus. Depending on the needs of an organization and the type
of technology used, a LAN can be as simple as two PCs and a printer in someone’s
home office or it can extend throughout a company and include audio and video
peripherals. Currently LAN size is limited to a few kilometers.
HUB
C C C C
C C C C
C C C C
Fig: An isolated LAN connecting 12 computers to a HUB in a closet

20. LAN is designed to allow resources to be shared between personal computers and
workstations. The resources to be shared can include hardware, software or data.
WAN:
A Wide Area Network (WAN) provides long distance transmission of data, image,
audio and video information over large geographic areas that may comprise a
country, a continent or even the whole world. We normally refer to the first as a
switched WAN and to the second as a point to point WAN.
The switched WAN connects the end systems, which usually comprise a router.
The point to point WAN is normally a WAN leased from a telephone or cable TV
provider that connects a home computer or a small LAN to an Internet Service
Provider.
MAN:
A Metropolitan Area Network (MAN) is a network with a size between a LAN and a
WAN. It normally covers the area inside a town or a city. It is designed for
customers who need high speed connectivity, normally to the internet and have
end points spread over a city or part of a city.
16) Definition of Network Address, Internet Protocol & IP
Address :
Network Address: Network Address refers to the designation used in routing to
send packets to a remote network. Ex: 172.16.0.0
Internet Protocol: Internet Protocol is a set of standard communications and
routing mechanisms that allow network users to upload files send e-mail and
download WebPages.
IP Address: IP Address is a numeric identifier assigned to each machine on an
IP network. An IP address is software address not hardware address. The Network
ID identifies the TCP/IP hosts that are located on the same physical network. All
hosts on the same physical network must be assigned the same network ID to
communicate with each other.
32 bits
Network ID Host ID
The Host ID identifies a host within a network. The Network ID is the software ID.

21. Range of
Class
Network ID
0 – 127 A 0
128 – 191 B 10
192 – 223 C 110
224 – 239 D 1110
240 - 255 E 1111
32 Bits
8 Bits 8 Bits 8 Bits 8 Bits
Network ID Host ID Host ID Host ID
Network ID Network ID Host ID Host ID
Network ID Network ID Network ID Host ID
Multicast Address
Reserve For Future Use
17) Definition of E-Commerce & Its Advantages:
The face of doing business both within our country and overseas is rapidly
changing. The internet, Electronic Funds Transfer (EFT), e-commerce and the like
have brought with them both opportunities and threats.

22. Business competitors may no longer just the business down the street, but
rather a business located in any number of places around the world. The flip side of
course is that the potential market is now not just in local area but cashed up
consumers across the world.
E-commerce won’t go away. Online and internet commerce is currently
experiencing dramatic growth. According to experienced organizations, the
introduction of e-commerce can potentially:
 Lower transaction cost;
 Reduce inventory holdings;
 Provide a competitive business advantages;
 Expand one’s market;
 Increase speed to market;
 Streamline supply chain management.
E-commerce includes electronic trading, electronic messaging, Electronic Data
Interchange (EDI), Electronic Mail, electronic catalogues, internet, intranet and
extranet services.
Additional e-commerce resources:
 Test to find out if your business is e-commerce ready.
 Access a copy of the government’s e-commerce guide. This will provide the
e-business information and resources.
 Common type of e-commerce that one’s business may engage.
 The four webolution steps
 10 safe online shopping tips.
18) Definition of Contracts & Its Basics
Contracts:
 Law of Contracts;
 Issues for e-commerce.

23. Basics of Contract:
o Offer;
o Acceptance;
o Intentions to enter legal relations;
o Consideration;
o Legal Capacity;
o Genuine Consent.
 Offer:
 Clear statement of terms;
 Person who makes it prepared to be bound;
 Not just an invitation to treat.
 Acceptance:
 Unqualified agreement to terms of offer;
 Express or inferred by conduct;
 Can’t be forced on unwilling person.
 Time of creation of contract
 Contract formed at time and place the acceptance is communicated to
offeror.
 Termination or Revocation of contract
 Can be revoked prior to acceptance;
 Revocation must be communicated to offeror.
 Certainty
 Essential parts of contract must be clear and complete;
 Courts may imply a meaning;
 Uncertain term can be “severed”.
 Consideration
 Valuable Consideration;

24.  Passing between parties to contract;
 Can’t be unlawful or immoral.
 Intention
 Express;
 Inferred from the circumstances;
 Must be genuine consent – not obtained under duress.
 Capacity
 Age;
 Intellectual capacity.
 Terms & Conditions
 Express;
 Implied.
 Formalities
 Oral or written;
 Writing required under statute, for example – sale of land.
19) Practical Concerns For E-commerce Deals
 Identity and capacity of seller or buyer;
 Authenticity of offer and acceptance;
 When and where contract formed;
 Governing Law;
 Terms and Conditions;
 Agreement on electronic payment system;
 Security of information exchanges;
 Consequences on breach;
 Storing electronic data to prevent alteration.
20) Electronic Transactions Act

25. I. Electronic Transactions Act
Federal law with mirror state laws (NSW, VIC, WA);
To remove obstacles to electronic transactions, communications,
signatures and record keeping;
1 July 2001 applies to all federal laws unless exempted.
II. Electronic Transactions Act
 Validates electronic transactions;
 Given in writing met electrically now
 Government can specify technology requirements
 Business requirement valid only with consent
 Signature – parties free to agree on method;
 Production and retention of documents;
o Method must ensure integrity and accessibility.
 Time and place of dispatch and receipt of communication.
III. Electronic Transactions Act
 Time of dispatch is when it enters the first information system
outside control of sender;
 Time or receipt is when it enters an information system
designated by the addressee for receiving it;
 Place of dispatch and receipt taken to be respective places of
business.
IV. Electronic Transactions Act
 Record keeping OK electronically if law says
o Information to be recorded in writing;
o A written document to be kept;
o An electronic communication to be kept.
 Record must be kept identifying origin, destination, and time of
sending and receipt of electronic communication.

26. 21) Making of A Contract
• What terms do you want to include?
• What risks are you trying to avoid?
• How will disputes about contract be dealt with?
• What is the Governing Law?
• Who will sign it?
22) Setting Up A Business Entity
• Sole Trader
• Partnership
• Company
• Trust
A. Sole Trader
 All profits
 All losses
 All liabilities
 Own name or choose separate business name
 Register business name
B. Partnership
Basics
 Carrying on a business;
 With a view to profit.
 Established by written agreement, oral agreement or conduct.
Law
 Partnership Act 1892 (NSW);
 Corporations Law: Not more than 20 partners (except doctors,
solicitors and accountants).

27. Features:
 Profit Sharing;
 Joint and several liability;
 Fiduciary duties to partners.
C. Companies
Law
 Corporations Act;
 Artificially legal entity;
 Liability of a member can be limited.
Features:
 Constitution;
 Directors Duties;
 Limits on raising money from the public.
A Company Can Form By:
 Registering name;
 Lodge application with ASIC;
 Registered office;
 Names of directors and members.
23) Choosing of the Structure
• Where is an entrepreneur getting his money from?
• What kind of risk involved?
• Who will be in control?
• What are the ongoing costs?

28. 24) Definition of Domain Name:
 Human friendly form of an Internet address.
 Actual address is an Internet Protocol (IP) number
 System globally administered by ICANN
 Generic top level domains (gTLDs)
 .com, .org, .net, .edu, .gov, .biz
 Country code top level domains (ccTLDs)
25) Domain Name Registration in Australia:
 Open and closed domains
 Open - .com, .org, .net, .info, .biz
 Closed - .gov, .edu, .mil
 auDA administers .com. au space
 To register in.au space must be commercial entity registered
and trading in Australia.
 Licensed on a first come first serve basis
 Domain names never meant to confer property rights
 Clash with trade marks
 auDA has a dispute resolution scheme which applies to all
domain names registered or renewed from 1 August 2002.
 ICANN has the UDRP for .com etc domains.
26) Domain Names & Other Business Identifiers:
 Trade Marks
 Personality Rights
 Place names

29.  Tension with domain names
o Reverse domain name hijacking
o Cybersquatting