If we have a organisation and we have 8-10 computers to work on. We need to share the data etc. etc.
The configuration of a communication network
What are network topologies?
In communication networks, a topology is a usually schematic description of the
arrangement of a network, including its nodes and connecting lines.
Why we use network topologies?
Network topology is used initially for planning the best way to design your
network to get maximum performance.
Types of Network Topologies
Computers in mesh topologies are
connected directly to each other
Data can be transmitted from
different devices simultaneously.
This topology can withstand high
Even if one of the components fails
there is always an alternative
present. So data transfer doesn’t
Expansion and modification in
topology can be done without
disrupting other nodes.
Connections not fully utilized.
Overall cost of this network is way
too high as compared to other
Set-up and maintenance of this
topology is very difficult. Even
administration of the network is
In a star topology all computers are
connected to a central device
known as hub or switch.
All the computers share data
through the Hub or Switch
A new node can be easily
connected to the existing network
by connecting it with unused port
If there is fault in cable connected
with computer, only the particular
computer get affected.
Less cables required than Mesh
Topology. That’s why it is
affordable by small organisations
If Hub or switch get faulty, all
computer connected to it will be
Traffic increased when computers
are simultaneously sending data to
In bus topology computers are
connected via a single cable known
as a Trunk or Backbone cable.
Trunk cable was then connected to
the branch cables which were
further connected to the PCs.
Uses less cables than star or mesh
Don’t need any special device like
Hub or Switch.
Main disadvantage is the difficulty
of troubleshooting it.
Bus topology is not scalable. New
node attaching to network is not
Backbone cable become faulty all
computer connected to it get
In ring topology all the nodes are
connected to each-other in such a way
that they make a closed loop.
Data travels around the network, in one
direction. Sending and receiving of data
takes place by the help of TOKEN.
Token Passing: Token contains a piece of
information which along with data is sent
by the source computer. This token then
passes to next node, which checks if the
signal is intended to it. If yes, it receives
it and passes the empty to into the
network, otherwise passes token along
with the data to next node. This process
continues until the signal reaches its
Each node gets to send the data when it
receives an empty token. This helps to
reduces chances of collision.
All the traffics flows in one direction only
at a very high speed.
No need for network server to control the
connectivity between workstations.
Each computer has equal access to
Receiver and repeater boost the signal
and send it to the next node along with
the token and data.
Each packet of data must pass
through all the computers between
source and destination. This makes it
If one workstation or port goes down,
the entire network gets affected
Difficult to add and remove devices
once the network has been set up.
Data sharing accomplished through
one direction only. It takes more
time to send or receive data.
Integrates the characteristics of
star and bus topology.
In tree topology number of star
network connected using bus. The
backbone cable is called as Bus.
Expansion of Network is possible and
Networks divided into segments, that
can be easily maintained.
Error detection and correction is
Each segment is provided with
dedicated point-to-point wiring to
the central hub.
If one segment is damaged, other
segments are not affected.
Relies heavily on the main bus
cable, if it breaks whole network is
As more and more nodes and
segments are added, the
maintenance becomes difficult.
Heavy traffic cause the network
and make it slow.