A network is a collection
of data communication hardware, computers, data communication
software and data communication media, all connected in a
meaningful way to allow users to share information, resources
Networks are becoming increasingly important
in today's computing world. Almost every large office has
a network, and more are set up daily.
Networks can be made up of anything from
telephones or telegraphs to computers connected by fibre optic
cable. They can also be used for many things, from playing
games with multiple players to connecting various universities
There are 3 types of general networks:
This is a network that is owned and used by one firm
for its needs. It is not accessible by the rest of the world.
It is not restricted to a geographical area.
It is a network offered to the public, for a fee. Often these
public networks are based in a geographical area within a
country. The telephone system is an example.
This is a collection of private and public networks connected
to each other over international boundaries. The Internet
is a good example of this category of network.
In order to serve such varied needs, a number
of configurations is used for different networks.
In order to serve the needs of the organization,
networks are organized into three configurations:
LAN Local Area Network
This is a network that is located in one small geographical
area, such as a building. This is the type of network most
commonly used. The Internet is a network of over 40,000 networks
and is considered a Global Network. In addition to these configurations,
there are various topologies used when setting up a local
Network Configuration Topologies
Network topologies have gone through many
evolutions since the first network was introduced. After the
development of new technologies and methods, better, more
efficient designs have been introduced.
There are three main topologies that are
1. Bus Network
2. Ring Network
3. Star Network
A bus network is a line of computers connected
together by a cable. The cable is called the bus. The bus
must be terminated at both ends.
Data can flow between machines, and each
machine has some of the software used by the entire network.
This can lead to data clashes if the same request is made
at the same time by two machines. Ethernet uses a modified
type of bus network.
This sharing of information between machines
means that only one copy of the software and/or data has to
A ring network is a bus network that has
been attached at both ends. The data in a ring network travels
in 1 direction only. Data clashes can occur for the same reasons
as in a bus network.
In order to eliminate data crashes, an improvement
was made to the ring network by adding a token. A token is
an electronic impulse that runs around the ring. In a ring
network with a token, called a Token Ring Network, the token
travels around the ring, from machine to machine. A machine
can only send a request or receive data when the token is
at its machine. This eliminated data clashes since two requests
could no longer be entered at the same time.
A star network is a network where each machine
is connected to a central machine, called a server. The server
holds all the software, and the other machines, called nodes,
request the software from it. Since the server receives all
the requests, it can handle them one by one, and there are
no data crashes. It is possible to have a star network spawn
another star network.
This is an example of a star network:
A star network is a form of hierarchical
network because each machine can use the resources of higher
networks and machines, but not of the ones below it. The Novell
network in Computing Services in the Computer Centre is a
Star networks are one of the most
popular forms of network.