2. What is a Topology?
The physical topology of a network refers to the
configuration of cables, computers, and other
peripherals. Physical topology should not be
confused with logical topology which is the method
used to pass information between workstations.
Logical topology was discussed in the Protocol
chapter.
3. What Is Ring Topology?
Advantages and Disadvantages of
Ring Topology
4. What is a Ring Topology?
RING TOPOLOGY, also known as Ring network, is a type of network topology where each node is
exactly connected to two other nodes, forward and backward, thus forming a single continuous path
for signal transmission
There are two types of the Ring Topology based on the data flow:
•Unidirectional and,
•Bidirectional
A Unidirectional ring topology handles data traffic in either clockwise or anticlockwise direction. This data network,
thus, can also be called as a half-duplex network. A Unidirectional ring topology is thus easy to maintain
compared to the bidirectional ring topology.
Ex: SONET network, SDH network etc.
A SONET/ SDH is a standardized network protocol that transfers data streams over optical fibers. Whereas, a
bidirectional ring topology handles data traffic in both the direction and can be a full-duplex network.
5. ADVANTAGES OF RING TOPOLOGY:
•Reduced chances of data collision as each
release a data packet after receiving the token.
•Token passing makes ring topology perform
better than bus topology under heavy traffic
•No need of server to control connectivity
among the nodes
•Equal access to the resources
DISADVANTAGES OF RING TOPOLOGY:
•In Unidirectional Ring, a data packet must pass
through all the nodes.
Ex: Let’s say A, B, C, D, and E are a part of the ring
network. The data flow is from A towards B and
henceforth. In this condition, if E wants to send a
packet to D, the packet must traverse the entire
network to reach D.
•Single point of failure, that means if a node goes
down entire network goes down.
RING TOPOLOGY
6. What Is Mesh Topology?
Advantages And Disadvantages Of
Mesh Topology
7. What is Mesh Topology?
A mesh topology is a network topology in which all the network nodes are
individually connected to most of the other nodes. There is not a concept of a central
switch, hub or computer which acts as a central point of communication to pass on
the messages.
Unlike other network topologies, it can be divided into two kinds:
•Fully connected mesh topology and,
•Partially connected mesh topology
A fully connected mesh topology has all the nodes connected to every other node. If you
know the graph theory, then it is like a fully connected graph where all the nodes are
connected to every other node.
On the other hand, a partially connected mesh topology does not have all the nodes
connected to each other.
8. ADVANTAGES OF MESH TOPOLOGY:
•Each connection can carry its own data load
•It is robust
•A fault is diagnosed easily
•Provides security and privacy
DISADVANTAGES OF MESH TOPOLOGY:
•Installation and configuration are difficult if the
connectivity gets more
•Cabling cost is more and the most in case of a fully
connected mesh topology
•Bulk wiring is required
Mesh Topology
9. What Is Tree Topology?
Advantages And Disadvantages Of
Tree Topology
10. WHAT IS TREE TOPOLOGY?
A tree topology is a combination of a star network topology and a bus topology. In
tree topology, nodes of the underlying bus network topology are replaced with a
complete star topology.
There are certain special cases where tree topology is more effective:
•Communication between two networks
•A network structure which requires a root node, intermediate parents node, and leaf nodes
(just like we see in an n-tree) or a network structure which exhibits three level of hierarchy
because two level of hierarchy is already displayed in the star topology.
11. ADVANTAGES OF TREE TOPOLOGY:
•Scalable as leaf nodes can accommodate more
nodes in the hierarchical chain.
•A point to point wiring to the central hub at each
intermediate node of a tree topology represents a
node in the bus topology
•Other hierarchical networks are not affected if
of them gets damaged
•Easier maintenance and fault finding
DISADVANTAGES OF TREE
TOPOLOGY:
•Huge cabling is needed
•A lot of maintenance is needed
•backbone forms the point of failure
TREE TOPOLOGY
12. In a star network each device on the network has its own cable that connects to a switch or hub. A hub
sends every packet of data to every device, whereas a switch only sends a packet of data to the
destination device.
The star network
Advantages and disadvantages of a star network
The advantages of a star network are:
•it is very reliable – if one cable or device fails then all the
others will continue to work
•it is high-performing as no data collisions can occur
The disadvantages of a star network are:
•it is expensive to install as this type of network uses the
most cable (network cable is expensive)
•extra hardware is required (hubs or switches) which adds
to cost
•if a hub or switch fails, all the devices connected to it will
have no network connection
13. In a bus network all the workstations, servers and printers are joined to one cable (the
bus). At each end of the cable a terminator is fitted to stop signals reflecting back down
the bus.
The bus network
Advantages and disadvantages of a bus network
The advantages of a bus network are:
•it is easy to install
•it is cheap to install, as it doesn't require much
cable
The disadvantages of a bus network are:
•if the main cable fails or gets damaged the whole
network will fail
•as more workstations are connected the
performance of the network will become slower
because of data collisions
•every workstation on the network "sees" all of the
data on the network – this is a security risk
14. In a line topology—also known as daisy-chaining or bus topology—the host communicates directly with
all nodes through one bus line. A standard Ethernet device or switch can be added to the end of the chain
if desired and used as normal. Be aware that these devices will compete for network bandwidth with the
FieldDAQ device. Reliable system design requires awareness of the bandwidth consumed by each device
during operations. This topology offers no redundant links.
Line topology
Advantages:
•Simple and inexpensive installation, expansion, and
troubleshooting
•Ideal for low number of nodes. NI recommends a maximum of
15 nodes.
•No external switch needed
•Can cover long distances
Disadvantages:
•Any unpowered nodes and/or node failure disrupts network
communication
•Addition or removal of any node disrupts network
communication
•Failure of any Ethernet cable and/or improper cable
termination disrupts network communication
•Network performance and synchronization affected when
node count exceeds 15. Consider the star topology for systems
that require a greater number of nodes.