This document provides an overview of computer network types and topologies. It discusses the four main types of networks: local area networks (LANs), personal area networks (PANs), metropolitan area networks (MANs), and wide area networks (WANs). Each network type is defined based on its size and scope. The document also examines common network topologies like bus, star, ring, mesh, tree, and hybrid along with their advantages and disadvantages. Finally, it briefly introduces some network technologies including intranets, extranets, and the internet.

1. CITY UNIVERSITY
Course Title: Computer Networks
Course Code: CSE317
Topics Name: Classification Of Computer Networks
Submitted By:
Afsana Akther Rubi
ID No: 1834902553
Batch: 49th
Submitted To:
Pranab Bandhu Nath
Senior Lecturer
Department of CSE
City University

2. Computer Network:
A computer network is a set of connected computers. Computers on a network are called nodes.
The connection between computers can be done via cabling, most commonly the Ethernet cable,
or fiber optic cable. Connections can also be wireless; you'll hear the term Wi-Fi to describe
information sent via radio waves.
Types of Computer Network:
A computer network can be categorized by their size. A computer network is mainly of four
types:
o LAN(Local Area Network)
o PAN(Personal Area Network)
o MAN(Metropolitan Area Network)
o WAN(Wide Area Network)
LAN (Local Area Network):
o Local Area Network is a group of computers connected to each other in a small area such
as building, office.
o LAN is used for connecting two or more personal computers through a communication
medium such as twisted pair, coaxial cable, etc.
o It is less costly as it is built with inexpensive hardware such as hubs, network adapters,
and Ethernet cables.
o The data is transferred at an extremely faster rate in Local Area Network.
o Local Area Network provides higher security.

3. Figure: Local Area Network
PAN (Personal Area Network):
o Personal Area Network is a network arranged within an individual person, typically
within a range of 10 meters.
o Personal Area Network is used for connecting the computer devices of personal use is
known as Personal Area Network.
o Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area
Network.
o Personal Area Network covers an area of 30 feet.
o Personal computer devices that are used to develop the personal area network are the
laptop, mobile phones, media player and play stations.
Figure: Personal Area Network

4. There are two types of Personal Area Network:
o Wired Personal Area Network
o Wireless Personal Area Network
Wireless Personal Area Network: Wireless Personal Area Network is developed by
simply using wireless technologies such as Wi-Fi, Bluetooth. It is a low range network.
Wired Personal Area Network: Wired Personal Area Network is created by using the
USB.
MAN (Metropolitan Area Network)
o A metropolitan area network is a network that covers a larger geographic area by
interconnecting a different LAN to form a larger network.
o Government agencies use MAN to connect to the citizens and private industries.
o In MAN, various LANs are connected to each other through a telephone exchange line.
o The most widely used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3,
ADSL, etc.
o It has a higher range than Local Area Network (LAN).
Figure: Metropolitan Area Network
WAN (Wide Area Network)
o A Wide Area Network is a network that extends over a large geographical area such as
states or countries.

5. o A Wide Area Network is quite bigger network than the LAN.
o A Wide Area Network is not limited to a single location, but it spans over a large
geographical area through a telephone line, fiber optic cable or satellite links.
o The internet is one of the biggest WAN in the world.
o A Wide Area Network is widely used in the field of Business, government, and
education.
Figure: Wide Area Network
Network Topology:
Network topologies describe the methods in which all the elements of a network are mapped.
Network topologies can be either logical or physical.
1. Physical – The physical network topology refers to the actual connections (wires, cables,
etc.) of how the network is arranged. Setup, maintenance, and provisioning tasks require
insight into the physical network.
2. Logical – The logical network topology is a higher-level idea of how the network is set
up, including which nodes connect to each other and in which ways, as well as how data
is transmitted through the network. Logical network topology includes any virtual and
cloud resources.

6. The Most Common Type of Network Topology:
1. Bus Topology:
Bus Topology uses one cable. All the peripheral devices are connected in series to that
cable. A special device, called terminator, is attached at the cable’s start and end
points, to stop network signals so they do not break down the cable.
Advantage of Bus Topology:
Bus Topology is that it uses the less cabling of any topology.
Disadvantage of Bus Topology:
Bus Topology is that extra circuitry ad software are used to keep data packets from
colliding with one another. A broken connection can bring down all part of the
network.
2. Star Topology:
Star Topology probably the most common topology. In star network, all nodes are
connected to a device called hub and communicate through it. Data packets travel
through the hub and are sent to attached nodes, eventually reaching their destinations.
Some hubs - known as intelligent hubs- can monitor traffic and help prevent collisions.
Advantages of Star Topology :
In star topology a broken connection between a node and the hub does not affect the
rest of the network.
Disadvantage of Star Topology:
If the hub is lost, however all the nodes connected to that hub are unable to
communicate.

7. 3. The Ring Topology :
The Ring Topology connects the network’s nodes in a circular chain, with each node
connected to the next. The last node connected to the first, completing the ring. Each
node examines data as it travels through the ring.
Advantages of Ring Topology:
There is no danger of collisions because only one packet of data travels the ring at a
time.
Disadvantages of Ring Topology:
If the ring is broken, however, the entire network is unable to communicate.
4. Mesh Topology:
Mesh Topology is the least used network topology and the most expensive to
implement. In mesh environment, a cable runs from every computer to every other
computer.
Advantage of Mesh Topology:
The big advantage to this arrangement is that data can never fail to be delivered. If
anyone connection goes down, there are other ways to route the data to its destination.
Disadvantage of Mesh Topology:
Most expensive network as large amount of cabling is required. Expensive hardware
and software is needed to implement this network.
5. Tree Topology or Hierarchical Topology :
Tree Topology is the combination of the characteristics of a star topology and a bus
topology. In this topology, a star -configured workstation in a group are connected to
cable which acts as a linear bus backbone. The tree bus can connect only with the hub
device directly. It has a central hub acts as a root of a tree of a network device. It has a
central root node which is connected to one or more nodes present in the lower
hierarchical topology.
Advantage of Tree Topology:
Point to point wiring for every segment is the main advantage. It is also supported by
most of the hardware and software vendors.
Disadvantage of Tree Topology:
The type of the cabling limits the overall length of each segment. When the backbone
line breaks, it leads to the breakdown of the complete segment. Tree topology becomes
more difficulty to configure and wire comparison to the other topologies.
6. Hybrid Topology :
Hybrid Topology is a combination of any two or more network topologies. The
topology obtained as a result of connecting two basic network topologies together

8. retains the basic character of the network and is not a hybrid network.
Consider the example of a tree network which is connected to another tree network; the
resulting network is still a tree network but not a hybrid network.
Advantage of Hybrid Topology:
1. Reliable
2. Effective
3. Flexible
4. Scalable
Disadvantage of Hybrid Topology:
1. Complexity
2. Expensive
Network Technology:
Network Technology involves the use of data systems to manage and deliver digital
resources over a computer network. A variety of industries use computer hardware and
system software that maintains a network, creating a need for specialists to manage
them.
Intranet:
An intranet is a private network, operated by a large company or other organization,
which uses internet technologies, but is insulated from the global internet
Extranet:
An extranet is an intranet that is accessible to some people from outside the company,
or possibly shared by more than one organization.
Internet:
An intranet is a computer network for sharing information, collaboration tools,
operational systems, and other computing services within an organization, usually to
the exclusion of access by outsiders.