Topologies
Star toology .
A star topology has one central node with all of the other
nodes connected to it. The central node would typically be a
hub or a switch that could transfer data between nodes.
If a hub is in the central node then it will broadcast the data to
all nodes connected to it. If a switch is in the central node then
it will transfer the data to the required location.
Advantages Disadvantages
● A damaged link only affects the ● The central node is a single point
attached node of failure
● You can easily add new nodes ● It requires many more cables than
● It works well under heavy load — bus and ring, which is expensive
especially when using a switch for
the central node
Bus topology .
With a bus topology, each node is connected to a single cable.
When data is sent from one node to another it is sent in both
directions. Terminators are placed at the end of the cable to
stop the signal being reflected back down the cable. The data
is sent to all nodes connected to the bus. It is only accepted by
the node that requires it.
Advantages Disadvantages
● A bus network is cheap because it ● If the main cable fails then the
uses minimal cables whole network fails
● A bus network is simpler to set up ● It isn’t very secure because data is
than other arrangements sent to all nodes on the network
● It works well for very small ● As more nodes are connected, the
networks network performance reduces
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KS4 – Networks Learner activity sheet
Lesson 4 – Network topologies
Ring topology .
In this arrangement, each node is connected in a ring. When
data is transferred it moves around the ring in one direction.
The data will continue to move around the ring until it reaches
its destination.
Advantages Disadvantages
● It performs better than the bus ● There is a single point of failure —
topology when under heavy load if there is a break in the loop then
● Additional nodes have a minimal data cannot be transferred
impact on the network ● It isn’t very secure because all
performance nodes can potentially see all of the
● There is less chance for data data
collision because the data moves ● The whole network is as slow as
in one direction, this makes data the slowest link between any two
transmission quite fast nodes
● To add a new node, the whole
network needs to be shutdown
Mesh topology .
In this arrangement, there are multiple ways for data to
transfer from one node to another. Each node is connected to
at least one other node. It is more common for them to be
connected to more than one node.
In a mesh network the most efficient route is typically
calculated before transferring the required data.
Advantages Disadvantages
● There is no central node, so there ● The increased cabling required for
is no single point of failure a wired network makes it
● The data uses the most direct expensive
route, making data transfer faster ● A wired mesh is far more
● It works well under heavy load complicated to manage and
● If a node breaks then a new route maintain than the other topologies
can be found for the data
● New nodes can be added without
shutting down the network
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KS4 – Networks Learner activity sheet
Lesson 4 – Network topologies
Scenario 1 .
A research laboratory needs a group of three computers connected together to share
resources. The network will be temporary because it is for a short experiment. The
computers will be in a secure room and each user will have access to each computer,
this means data transfer security isn’t a high priority. The majority of the scientists’
funding has been spent on the experiments so there are very limited funds to create this
network.
Underline the most suitable topology for this scenario:
Star Bus Ring Mesh
Draw a graph of your chosen topology below:
Justify your chosen topology in the space below:
I choose the bus topology because it is cheap and can therefore work well with a limited budget. Moreover,
there are only three researchers so it doesn’t have to be a big topology.
Scenario 2 .
A homeowner is building their dream house. There are four bedrooms and two offices in
the new home. The homeowner wants a stable connection from each room to a central
location. The central location will also be connected to the internet and a printer. The
homeowner doesn’t require a direct connection from room to room but would like the
ability to connect through the central location on occasion when the family might want
to share photographs or videos with each other through the network. They have a
reasonable budget but want to avoid any unnecessary costs. The homeowner
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Lesson 4 – Network topologies
anticipates that the network will be heavily used so it will need to be able to cope with
high demand.
Underline the most suitable topology for this scenario:
Star Bus Ring Mesh
Draw a graph of your chosen topology below:
Justify your chosen topology in the space below:
The star topology works well under a heavy load which is a requirement of the homeowner.
They have a big budget and can therefore afford to add new nudes and cables.
Scenario 3 .
A new tech startup company has an office space that currently requires 20 users to be
connected to a network. There will be a mixture of laptops and desktop computers. They
also require shared, high-speed internet access and a shared laser printer. The network
must be fast and stable. It should also be easy to add new devices to the network
without having to shutdown the network or compromise on stability and speed. Users of
the network will need to be in constant contact with other users in the network through
an internal messaging system, this must be fast and reliable to increase productivity.
The tech company has two wealthy backers and they have an excellent budget for
setting up their network.
Underline the most suitable topology for this scenario:
Star Bus Ring Mesh
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KS4 – Networks Learner activity sheet
Lesson 4 – Network topologies
Draw a graph of your chosen topology below:
Justify your chosen topology in the space below:
The tech company had a big budget and can afford the increase in cabling. The mesh topology can sustain the heavy load
required by the different users and transmits information at a hight speed. In addition, the mesh topology does not need to
be shut down in case new nodes have to be added.
Scenario 4 .
A small printing company has been using stand alone computers (computers not
connected to a network) for several decades. They have five computers and three
industrial printers. They would like to upgrade their IT infrastructure to enable all
computers on the network to share a connection with the printers. They also want the
ability to share an internet connection and to send data to other computers on the
network. The network will be in a secured location and not accessible to the public. Data
transfer must be fast because they will be sending large amounts of data to the
industrial printers. They also would like the option to expand the network in the future if
they need to. The company doesn’t have a large budget for this project.
Underline the most suitable topology for this scenario:
Star Bus Ring Mesh
Draw a graph of your chosen topology below:
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Lesson 4 – Network topologies
Justify your chosen topology in the space below:
The ring topology is not a secure network but the printing company is already in a secure network.
It works well under heavy load.
Explorer task .
Decide which hardware components might be required for the network topologies that
you have chosen and the scenarios given. You can draw or list them.
Scenario 1
Scenario 2
Scenario 3
Scenario 4
Resources are updated regularly — the latest version is available at: ncce.io/tcc.This resource is licensed
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