Network Topologies

1. Network topology is the arrangement of the
various elements (links, nodes, etc.) of
a computer network.
It defines the specific characteristics of a
network.
such as where all the workstations and other
devices are located
and the precise arrangement of all the
physical media like cables.

2. There are different topologies that make up
computer networks. Many networks are a
combination of the various topologies that we
will look at:
BUS
Star
Ring
Mesh
Point-to-point
Point-to-multipoint
Hybrid

3. A bus is a network topology in which nodes
are directly connected to a common linear (or
branched) half-duplex link called a bus.
In local area networks where bus topology is
used, each node is connected to a single
cable, by the help of interface connectors.
A signal from the source travels in both
directions to all machines connected on the
bus cable.

5. When the electrical signal reaches the end of
the bus
As a solution the two endpoints of the bus
are normally terminated. to prevent
an RFsignal from being reflected back from
each end, causing interference, or power
loss.

7. Advantages Disadvantages
Cheap and easy to implement Network disruption when
computers are added or removed
Require less cable A break in the cable will Result all
systems to fail from accessing the
network.
Does not use any specialized
network equipment
Difficult to troubleshoot
Advantages

8. Star networks are one of the most common
computer network topologies.
In its simplest form a star network consists of
one central hub.
In star topology every node (computer
workstation or any other peripheral) is
connected to a central hub.

10. Advantages Disadvantage
Easy to connect new nodes ordevices The central hub is a single point of failure
Centralized management. It helps in
monitoring the network
Can have a higher cost to implement,
especially when using a switch or router as
the central networkdevice

11. A ring topology is a bus topology in a closed
loop. Data travels around the ring in one
direction.
Rings can be unidirectional with all traffic
travelling either clockwise or anticlockwise
around the ring
A token ring network is a local area
network (LAN) topology where
nodes/stations are arranged in a ring
topology.
Data passes sequentially between nodes on the
network until it returns to the source station.

13. To prevent congestion and collision, a token
ring topology uses a token to ensure that
only one node/station on the line is used at a
time, thereby easily denoting media users of
its activity.
A Media Access Unit (MAU) also known as
a Multi-station Access Unit (MAU or MSAU) is
a device to attach multiple network stations
in a star topology as a token ring network.
internally wired to connect the stations into a
logical ring (generally passive i.e. non-
switched and unmanaged; however managed
token ring MAUs do exist in the form of CAUs
or Controlled Access Units).

15. Token contains a piece of information which
along with data is sent by the source
computer
token ring supported 4Mbps or 16mbps This
token then passes to next node, which checks
if the signal is intended to it.

16. Advantages Disadvantages
Easily expanded without disruption
to the network
Requires more cable
Cable failure affects only a single
user

17. A network setup where each computer and
network device is interconnected with one
another, allowing for most transmissions to be
distributed, even if one of the connections go
down.
A mesh topology can be a full mesh topology
or a partially connected mesh topology.
In a full mesh topology, every computer in the
network has a connection to each of the other
computers in that network.
The number of connections in this network can
be calculated using the following formula (n is
the number of computers in the network): n(n-
1)/2.

19. In a partially connected mesh topology, at
least two of the computers in the network
have connections to multiple other computers
in that network.
It is an inexpensive way to implement
redundancy in a network.

21. Reliability: problems in a cable affect only the
two nodes attached to it.
Adding additional devices does not disrupt
data transmission between other devices.
Can handle high amounts of traffic, because
multiple devices can transmit data
simultaneously.

22. Disadvantages of a mesh topology
Building and maintaining the topology is
difficult and time consuming.
The cost to implement is higher than other
network topologies, making it a less desirable
option.

23. A hybrid topology is a type of network
topology that uses a combination of any two
or more topologies in such a way that the
resulting network does not exhibit one of the
standard topologies (e.g., bus, star, ring, tree
topology, etc.).
A hybrid topology is always produced when
two different basic network topologies are
connected. Two common examples for Hybrid
network are: star-ring network and star bus
network.

25. Advantages of Hybrid Topology
Very reliable and easy to detect the Faulty
system.
It includes both wired and wireless network.
It is expandable network.
Disadvantages of Hybrid Topology
It’s design is difficult to understand.
The cost of this network design is high,
because of requirement of lot of cables,
cooling systems, etc.

26. Point to point is the simplest topology with a
dedicated link between two endpoints; the
point-to-point connection is a unicast
connection.
There is a dedicated link between an
individual pair of sender and receiver.
The capacity of the entire channel is reserved
only for the transmission of the packet
between the sender and receiver.

28. Explain network topology
Write a note with bus topology
Write advantage and disadvantage of bus
topology
Explain mesh topology
Explain star topology
State advantage and disadvantage of a hybrid
topology
Tell example of network topology wich is
MAN area network