4. DEFINITION
Network topology refers to the
physical or logical layout of a
network. It defines the way
different nodes are placed and
interconnected with each other.
Network topology may describe how
the data is transferred between
these nodes.
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5. Types of topology
There are two types of network
topologies:
Physical Topology
logical Topology
Physical Topology emphasizes the physical
layout of the connected devices and
nodes.
logical Topology focuses the pattern of
data transfer between network nodes.
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6. Both Physical and
Logical Network
Topologies can be
categorized into 6
basic types:
Bus Topology
Ring Topology
Star Topology
Tree Topology
Mesh Topology
Hybrid Topology
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7. BUS TOPOLOGY
In Bus Topology, all
devices are connected
sequentially to the same
backbone or transmission
line.
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A signal from the source
travels in both
directions to all
stations until it finds
the intended recipient.
If the station address
matches the intended
address, it accepts the
data otherwise ignored.
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8. Bus Topology is further divided into 2 types:
Linear Bus- All of the nodes of the network are
connected to a common transmission medium
which has exactly two endpoints.
Distributed Bus- All of the nodes of the
network are connected to a common transmission
medium which has more than two endpoints.
A fully connected Bus Topology is having only 1
linking channel.
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9. Use: Local Area Network(LAN)
AdvantageLess expensive and easy to implement.
DisadvantageSince one cable is utilized, when it breaks,
the entire network will be terminated.
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10. RING TOPOLOGY
In Ring Topology, all
network devices are
connected
sequentially to a
backbone forming a
physical ring.
Here the data flow is
unidirectional, so
when a device sends
data, it must travel
through each device
on the ring until it
reaches its
destination.
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11. A fully connected Ring Topology is having (n)
linking channels.
Use: Local Area Network(LAN)
AdvantageLess expensive in nature.
DisadvantageSince one cable is used, when it fails, the
whole network will be effected.
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12. STAR TOPOLOGY
In Star Topology, all
the nodes in the
network are connected
to a central device
called Hub or Switch
via cables.
All traffic is
controlled by the
Hub. Devices transfer
the data to each
other only through
the Hub not directly.
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13. Star Topology is further divided into 2 types:
Extended Star- A network which has one or more
repeaters used to extend the maximum distance
between the Hub and other devices.
Distributed Star- A network which is composed
of individual networks connected in a linear
fashion with no central connection.
A fully connected Star Topology is having (n)
linking channels.
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14. Use: Client-Server network
AdvantageSimple, Easy to design and implement.
Disadvantage• Since a central Hub controls all devices, if
it fails, the entire network will be
terminated.
• Wiring is more, so highly expensive.
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15. TREE TOPOLOGY
In Tree Topology, a
root node is
connected to two or
more sub-level nodes,
which themselves are
connected
hierarchically to
sub-level nodes.
Here the top level node
is called Root and
the low level node is
called Child.
It is the combination
of Bus and Star
Topology.
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16. Use: Cable TV technology, Wireless networks for
military, Mobile applications
Advantage• Easier fault identification and isolation.
• It is scalable; Secondary nodes allow more
devices to be connected to a central node.
Disadvantage• Maintenance of the network may be difficult when
the network spans a great area.
• Since it is a variation of bus topology, if the
backbone fails, the entire network is crippled.
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17. MESH TOPOLOGY
In Mesh Topology,
each node is
directly connected
to some or all the
other nodes present
in the network.
A fully connected
Mesh Topology is
having n(n-1)/2
linking channels.
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18. Mesh Topology is further divided into 2 types:
Fully Connected- A network in which every node is
connected to each other. It doesn't need to
use switching nor broadcasting.
Partially Connected- A network in which some of
the nodes are connected to more than one other.
Use: Long distance transmission of data
It has more disadvantages so that rarely used.
Disadvantage• Message delay may be high.
• Requires more cabling, hence costly.
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19. HYBRID TOPOLOGY
Hybrid Topologies
use a combination
of any two or
more topologies
in such a way
that the
resulting network
does not exhibit
one of the
standard
topologies.
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20. A hybrid topology is always produced when
two different basic network topologies are
connected.
For Example: Star-Ring network and Star-Bus
network
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21. REFERENCES
Data Communications and Networking : Behrouz A.
Forouzan, Tata MCGraw-Hill, 4th Ed
Computer Networks: A.S. Tannenbum, D.Wetherall,
Prentice Hall, Imprint of Pearson,5th Ed
http://en.wikipedia.org/wiki/Network_topology
http://www.techopedia.com/definition/5538/network-
topology
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