Network Topologies
1. Bus topologyCommonly referred to as a linear bus, all the devices on a bus topology are connected by
one single cable. The main problem faced in implementing this topology is the fact that only one
communication channel exists to serve the entire network. As a result, if this channel fails, the
whole network will go out of operation,
Advantages
1. It is easy to handle and implement.
2. It is best suited for small networks.
3. Easy to connect a computer or peripheral to a linear bus
4. Requires less cable length than mesh or star topologies.
5. It is cheaper than any other topologies
1. It is easy to handle and implement.
2. It is best suited for small networks.
3. Easy to connect a computer or peripheral to a linear bus
4. Requires less cable length than mesh or star topologies.
5. It is cheaper than any other topologies
Disadvantages
1. The cable length is limited. This limits the number of stations that can be connected.
2. This network topology can perform well only for a limited number of nodes
3. If the network cable breaks, the entire network will be down.
4. Terminators are required at both ends of the backbone cable.
5. Difficult to identify the problem if the entire network shuts down.
6. Not meant to be used as a stand-alone solution in a large building.
7. Include difficult reconnection and fault isolation.
8. The managing cost of network is too high.
9. Addition of new devices requires modification or replacement of the backbone.
1. The cable length is limited. This limits the number of stations that can be connected.
2. This network topology can perform well only for a limited number of nodes
3. If the network cable breaks, the entire network will be down.
4. Terminators are required at both ends of the backbone cable.
5. Difficult to identify the problem if the entire network shuts down.
6. Not meant to be used as a stand-alone solution in a large building.
7. Include difficult reconnection and fault isolation.
8. The managing cost of network is too high.
9. Addition of new devices requires modification or replacement of the backbone.
2. Star and Tree Topology
The star topology is the most commonly used architecture in Ethernet LANs. Larger networks use the extended star topology also called tree topology. When used with network devices that filter frames or packets, like bridges, switches, and routers, this topology significantly reduces the traffic on the wires by sending packets only to the wires of the destination host.
The star topology is the most commonly used architecture in Ethernet LANs. Larger networks use the extended star topology also called tree topology. When used with network devices that filter frames or packets, like bridges, switches, and routers, this topology significantly reduces the traffic on the wires by sending packets only to the wires of the destination host.
Advantages
1. Due to its centralized nature, the topology offers simplicity of operation.
2. It also achieves an isolation of each device in the network.
3. Easy to install and reconfigure.
4. No disruptions to the network when connecting or removing devices.
5. Easy to detect faults and to remove parts.
6. Less expensive.
7. Includes robustness, that is, if one link fails, only that link is affected, other links remain active.
8. Easy to install and reconfigure.
9. No disruptions to the network when connecting or removing devices.
10. Easy to detect faults and to remove parts.
11. Less expensive.
12. Includes robustness, that is, if one link fails, only that link is affected, other links remain active.
1. Due to its centralized nature, the topology offers simplicity of operation.
2. It also achieves an isolation of each device in the network.
3. Easy to install and reconfigure.
4. No disruptions to the network when connecting or removing devices.
5. Easy to detect faults and to remove parts.
6. Less expensive.
7. Includes robustness, that is, if one link fails, only that link is affected, other links remain active.
8. Easy to install and reconfigure.
9. No disruptions to the network when connecting or removing devices.
10. Easy to detect faults and to remove parts.
11. Less expensive.
12. Includes robustness, that is, if one link fails, only that link is affected, other links remain active.
Disadvantages
1. The network operation depends on the functioning of the central hub. Hence, the failure of
the central hub leads to the failure of the entire network.
2. If the hub, switch, or concentrator fails, nodes attached are disabled.
3. Requires more cable length than a bus topology.
4. More expensive than bus topologies because of the cost of the hubs, etc.
1. The network operation depends on the functioning of the central hub. Hence, the failure of
the central hub leads to the failure of the entire network.
2. If the hub, switch, or concentrator fails, nodes attached are disabled.
3. Requires more cable length than a bus topology.
4. More expensive than bus topologies because of the cost of the hubs, etc.
3. Ring TopologyIn local area networks where the ring topology is used, each computer is connected to the network in a closed loop or ring. The signal passes through each machine or computer connected to the ring in one direction, from device to device, until it reaches its destination. Each machines or computers connected to the ring act as signal boosters or repeaters. When a device receives a signal intended for another device, its repeater regenerates the bits and passes them along. Two types of ring topology can be found.
*Single ring – All the devices on the network share a single cable (e.g Token ring)
* Dual ring – The dual ring topology allows data to be sent in both directions (eg, FDDI).
Redundant path provides fault tolerance
*Single ring – All the devices on the network share a single cable (e.g Token ring)
* Dual ring – The dual ring topology allows data to be sent in both directions (eg, FDDI).
Redundant path provides fault tolerance
Advantages
1. It is relatively easy to install and reconfigure.
2. Easy to identify the problem if the entire network shuts down.
3. The data being transmitted between two nodes passes through all the intermediate nodes. A
central server is not required for the management of this topology.
1. It is relatively easy to install and reconfigure.
2. Easy to identify the problem if the entire network shuts down.
3. The data being transmitted between two nodes passes through all the intermediate nodes. A
central server is not required for the management of this topology.
Disadvantages
1. The failure of a single node of the network can cause the entire network to fail.
2. The movement or changes made to network nodes affects the performance of the entire
network.
3. Only one machine can transmit on the network at a time.
4. Mesh TopologyThe mesh topology connects all devices (nodes) to each other for redundancy and fault tolerance.It is used in WANs to interconnect LANs and for mission critical networks like those used by banks and financial institutions. Implementing the mesh topology is expensive and difficult.1. The failure of a single node of the network can cause the entire network to fail.
2. The movement or changes made to network nodes affects the performance of the entire
network.
3. Only one machine can transmit on the network at a time.
Advantages
1. The arrangement of the network nodes is such that it is possible to transmit data from one
node to many other nodes at the same time.
2. Eliminates traffic problems in links sharing.
3. If one link becomes unusable, it does not incapacitate the entire system. Thus, act as robust.
4. It has privacy and security.
5. Point-to-point link make fault identification and fault isolation easy
1. The arrangement of the network nodes is such that it is possible to transmit data from one
node to many other nodes at the same time.
2. Eliminates traffic problems in links sharing.
3. If one link becomes unusable, it does not incapacitate the entire system. Thus, act as robust.
4. It has privacy and security.
5. Point-to-point link make fault identification and fault isolation easy
Disadvantages
1. Installation and reconnection are difficult.
2. The hardware required to connect each link (I/O ports and cable) is expensive.
3. It is generally too costly and complex for practical networks.
4. The arrangement wherein every network node is connected to every other node of the
network, many of the connections serve no major purpose. This leads to the redundancy of
many of the network connections.
1. Installation and reconnection are difficult.
2. The hardware required to connect each link (I/O ports and cable) is expensive.
3. It is generally too costly and complex for practical networks.
4. The arrangement wherein every network node is connected to every other node of the
network, many of the connections serve no major purpose. This leads to the redundancy of
many of the network connections.
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