Computer network-and Network topology report

1. Information Technology In Business (ITB)
REPORT
ON
COMPUTER NETWORKS & NETWORK TOPOLOGIES
Submitted to:
Professor RIZWAN ALI
Computer Networks and network topologies
Introduction:
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 wirelessly through radio waves. Connected computers can
share resources, like access to the Internet, printers, file servers, and others. A network is a
multipurpose connection, which allows a single computer to do more.
Computer network is a telecommunication channel through which we can
share our data. It is also called data network. The best example of computer network is
Internet. Computer network does not mean a system with control unit and other systems as
its slave. It is called a distributed system.

3. Types of Computer Networks
The size of a network can be expressed by the geographic area they occupy and the
number of computers that are part of the network. Networks can cover anything from a
handful of devices within a single room to millions of devices spread across the entire globe.
Some of the different networks based on size are:
 Personal area network, or PAN
 Local area network, or LAN
 Metropolitan area network, or MAN
 Wide
area network, or
WAN
Personal Area Network:
A personal area network, or PAN, is a computer network
organized around an individual person within a single building. This could be inside a small
office or residence. A typical PAN would include one or more computers, telephones,
peripheral devices, video game consoles and other personal entertainment devices.
Local Area Network:
A local area network, or LAN, consists of a computer network at a
single site, typically an individual office building. A LAN is very useful for sharing resources,
such as data storage and printers. LANs can be built with relatively inexpensive hardware,
such as hubs, network adapters and Ethernet cables.
Metropolitan Area Network:
A metropolitan area network, or MAN, consists of a
computer network across an entire city, college campus or small region. A MAN is larger
than a LAN, which is typically limited to a single building or site. Depending on the
configuration, this type of network can cover an area from several miles to tens of miles.
Wide Area Network:

4. A wide area network, or WAN, occupies a very large area, such as
an entire country or the entire world. A WAN can contain multiple smaller networks, such as
LANs or MANs. The Internet is the best-known example of a public WAN.
Typesof Network Topology
In communication networks, a topology is a usually schematic description of the
arrangement of a network, including its nodes and connecting lines. There are two ways of
defining network geometry: the physical topology and the logical (or signal) topology.
 BUS Topology
 RING Topology
 STAR Topology
 MESH Topology
 TREE Topology
 HYBRID Topology
BUS Topology:
Bus topology is a network type in where every computer and network
device is connected to single cable. Bus networks (not to be confused with the system bus of
a
computer
) use a
common
backbone
to
connect
all
devices.

5. Features of Bus Topology
 It transmits data only in one direction.
 Every device is connected to a single cable.
Advantages of Bus Topology
 Easy to expand.
 Cost effective.
Disadvantages of Bus Topology
 Data transfer only in one direction.
 Limited length of cables.
RING Topology:
In a ring network, every device has exactly two neighbors for
communication purposes. All messages travel through a ring in the same direction (either
"clockwise" or "counterclockwise").
Features of Ring Topology
 A number of repeaters are used and the transmission is unidirectional.
 Date is transferred in a sequential manner that is bit by bit.
Advantages of Ring Topology

6.  Cheap to install and expand.
 Each computer has equal access to resources.
Disadvantages of Ring Topology
 Trouble shooting is difficult.
 If one work station goes down, the entire network gets affected.
STAR Topology:
In this type of topology all the computers are connected to a single hub through a cable. This hub
is the central node and all others nodes are connected to the central node.
Features of Star Topology:
 Every node has its own dedicated connection to the hub.
 Acts as a repeater for data flow.
 Can be used with twisted pair, Optical Fibre or coaxial cable.
Advantages of Star Topology
 Fast performance.
 Easy to troubleshoot
Disadvantages of Star Topology
 High cost.
 Performance is based on hub.
MESH Topology:

7. It is a point-to-point connection to other nodes or devices. Traffic is
carried only between two devices or nodes to which it is connected. Mesh has n (n-2)/2
physical channels to link hn devices. Mesh topology introduces the concept of routes. Unlike
each of the previous topologies, messages sent on a mesh network can take any of several
possible
paths from
source to
destinatio
n.
Types of Mesh Topology:
 Partial Mesh Topology: In this topology some of the systems are connected in the
same fashion as mesh topology but some devices are only connected to two or three
devices.
 Full Mesh Topology: Each and every nodes or devices are connected to each other.
Features of Mesh Topology
 Fully connected.
 Robust.
 Not flexible.
Advantages of Mesh Topology
 Each connection can carry its own data load.

8.  Provide security and privacy .
Disadvantages of Mesh Topology
 Cabling cost is more.
 Bulk wiring is required.
TREE Topology:
It has a root node and all other nodes are connected to it forming a
hierarchy. It is also called hierarchical topology. It should at least have three levels to the
hierarchy. A tree topology joins multiple star topologies together onto a bus. In its
simplest form, only hub devices connect directly to the tree bus, and each hub
functions as the root of a tree of devices.
Features of Tree Topology
 Ideal if workstations are located in groups.
 Used in Wide Area Network.
Advantages of Tree Topology
 Easily manage and maintain.
 Error detection is easily turn.
Disadvantages of Tree Topology
 Expensive due to cabling.
 Scalability of the network depends on the type of cable used.

9. HYBRID Topology:
It is two different types of topologies which is a mixture of two or more
topologies. Hybrid topology inherits merits and demerits of all the incorporating topologies.
For example if in an office in one department ring topology is used and in another star
topology is used, connecting these topologies will result in Hybrid Topology (ring topology
and star topology).
Features of Hybrid Topology:
 It is a combination of two or topologies
 Inherits the advantages and disadvantages of the topologies included
Advantages of Hybrid Topology
 Reliable as Error detecting and trouble shooting is easy.
 Effective.

10.  Scalable as size can be increased easily.
 Flexible.
Disadvantages of Hybrid Topology
 Complex in design.
 Costly.
Conclusion:
Topology remain an important part of network design theory. You can probably build a home
or small business computer network without understanding the difference between a bus
design and a star design, but becoming familiar with the standard topologies gives you a
better understanding of important networking concepts like hubs, broadcasts, and routes.
References:
http://www.studytonight.com/computer-networks/network-topology-types
http://study.com/academy/lesson/how-star-topology-connects-computer-networks-in-
organizations.html
http://www.tutorialspoint.com/data_communication_computer_network/computer_network_to
pologies.htm