Basic concept of Computer networks and distributed systems, Goals of networking, General approaches of communication within a network, Network classification, Uses & Network Softwares.

1. Assignment-2
Course title : Computer Network
Course code : CSE 317
Submitted to
Pranab Bandhu Nath
Senior Lecturer
CSE Department
City University
Submitted by
Shohana Akter kakon
ID : 1834902539
Semester : 8th
Batch : 49th

2. ARPANET
The ARPANET (advanced research projects agency network) was an early computer network,
constructed in 1969 as a robust medium to transmit sensitive military data and to connect
leading research groups throughout the United States. ARPANET first ran NCP (network
control protocol) and subsequently the first version of the Internet protocol or TCP/IP suite,
making ARPANET a prominent part of the nascent Internet.
NETWORK
A network is a collection of computers, servers, mainframes, network devices, peripherals, or
other devices connected to one another to allow the sharing of data.
Computer Networks
A system of interconnected computers and computerized peripherals such as printers is called
computer network. This interconnection among computers facilitates information sharing
among them. Computers may connect to each other by either wired or wireless media.
Distributed System
A distributed system is any network structure that consists of autonomous computers that are
connected using a distribution middleware. Distributed systems facilitate sharing different
resources and capabilities, to provide users with a single and integrated coherent network.
Goals of Computer Network
Resource Sharing
The main goal of the computer network is Resource Sharing. It is to create all the programs,
data and hardware accessible to anyone on the network without considering the resource’s
physical area and the client.

3. Reliability
If there are alternate sources of supply, all files could be replicated on two or more machines.
If one of them is not available, due to hardware failure, the other copies could be used.
Communication
Network users, located geographically apart, may converse in an interactive session through
the network. In order to permit this, the network must provide almost error-free
communications.
Flexible access
Files can be accessed from any computer in the network. The project can be begun on one
computer and finished on another.
Performance
It is measured in terms of transit time and response time. Transit time is the time for a
message to travel from one device to another. Response time is the elapsed time between an
inquiry and a response.
Performance is dependent on the following factors:
1. The number of users
2. Type of transmission medium
3. Capability of connected network
4. Efficiency of software
Security
Security is the main characteristics of Computer network where you can take necessary steps
for protecting your data from unauthorized access.

4. Saving Money
The second goal of a computer network is saving money. Small computers have a much
excellent value proportion than higher ones. Mainframes are approximately a method ten
times quicker than the quickest single-chip microprocessors, but they cost a huge number of
times more.
Scalability
Scalability increases the system performance by adding more processors.
Application of Computer Network
Business Applications
computer network is almost certainly going to be necessary in business sector. It's not enough
to simply have a computer in business a computer needs to be able to connect with other
computers and systems.
Communication Medium
The group of interconnected computer through transmission media in order to
communication and Share resources like hardware, data & software is known as
communication media. It is a system for communication between networks. The computers in
network may be connected through cable, telephone-line, beams etc.
E-commerce
E-Commerce or Electronic Commerce means buying and selling of goods, products, or services
over the internet. These services provided online over the internet network.
Home application
Home application like micro oven, washing machines, air conditioner system, remote control
base television & other electronics components are example application area of computer
networks.

5. Electronic commerce
Electron Commerce refers to any form of business transaction conducted online.
Mobile Users
Mobile computers, such as notebook computers and Mobile phones, is one of the fastest-
growing segment of the entire computer industry. Although wireless networking and mobile
computing are often related, they are not identical, as the below figure shows.
General approaches of communication with in a network
A communication network is the pattern of directions in which information flows in the
organization. Channels of communication (networks by which information flows) are either
formal networks or informal networks. Formal networks follow the authority chain and are
limited to task-related communications. The informal network (grapevine) is free to move in
any direction, skip authority levels, and is as likely to satisfy group members' social needs as it
is to facilitate task accomplishments.
Classification of computer Network
Types of computer networks
1. PAN (PERSONAL AREA NETWORK)
2. LAN (LOCAL AREA NETWORK)
3. WAN (WIDE AREA NETWORK)
4. MAN (METROPOLITON AREA NETWORK)
PAN (PERSONAL AREA NETWORK)
A personal area network (or PAN) covers a very small area. This type of network connects
devices within a certain range and if you move outside of that range, the connection can be
lost. For example, connecting your smartphone to a wireless speaker, headphones, or other
wireless device.

6. LAN (LOCAL AREA NETWORK)
A local area network (or LAN) covers a larger area like an office or a bigger premises. These
computers can be connected to the network using either a wired or wireless connection
media. Once connected, the computers on the network can share
WAN (WIDE AREA NETWORK)
WAN or Wide Area Network is a computer network that extends over a large geographical
area, although it might be confined within the bounds of a state or country. A WAN could be a
connection of LAN connecting to other LAN’s via telephone lines and radio waves and may be
limited to an enterprise (a corporation or an organization) or accessible to the public. The
technology is high speed and relatively expensive.
MAN (METROPOLITON AREA NETWORK)
MAN or Metropolitan area Network covers a larger area than that of a LAN and smaller area as
compared to WAN. It connects two or more computers that are apart but resides in the same
or different cities. It covers a large geographical area and may serve as an ISP (Internet Service
Provider). MAN is designed for customers who need a high-speed connectivity. Speeds of MAN
ranges in terms of Mbps. It’s hard to design and maintain a Metropolitan Area Network.
Uses & Network Software’s
Network software is an extremely broad term for a range of software aimed at the
design and implementation of modern networks. Various types of network
software support the creation, calibration and operation of networks.

7. Uses of network software
In using network software, the size and scope of a network plays a key role in decision making.
Companies or other parties can choose specific network software tools for setup and
installation. Other network software resources help administrators and security personnel to
monitor a network to protect it against a range of attacks, to prevent data breaches, or to limit
unauthorized access. Other tools help to make network operations work better.
Another category of network software is related to network virtualization. With new virtual
networks, various tools take the place of old legacy systems built on physical hardware setups.
In general, network software must be applied according to security needs. This can include
factors such as whether a network is attached to the global Internet as well as specific goals
and objectives for use.

8. https://www.wisdomjobs.com/e-university/principles-of-management-and-
organisational-behaviour-tutorial-366/communication-networks-12761.html
https://www.tutorialspoint.com/data_communication_computer_network/data
_communication_computer_network_tutorial.pdf