NETWORK TOPOLOGY

NETWORK TOPOLOGY

Network topology refers to the layout of the computers and devices in a communications network. It describes how each computer or device, also called a node, is connected to one another in a network.

TYPES OF NETWORK TOPOLOGY

• Bus Topology
• Ring Topology
• Star Topology

BUS TOPOLOGY

Layout:

• All computers and devices are connected to a single central cable
• The bus is physical cable that connects the computers and other devices
• Terminators are required at both ends of the backbone cable

Data Transfer:

• Data transmitted on a bus network travels along the bus in both directions
• When a sending device transmits data, the adress of the receiving device is included with the transmission so that the data is sent to the appropriate receiving device
• If the device address does not match the intended address for the data, the device ignores the data
• If the data address match the device address, the data is accepted

Advantages:

• Easy and inexpensive to set up
• Adding and removing nodes can be done without disturbing the rest of the network
• Failure of one node does not affect the rest of the network

Disadvantages:

• Failure of the central cable will shut down the entire network
• Only suitable for small size network
• Data collision may occur because data transmitted will travel in both directions

RING TOPOLOGY

Layout:

• All computers and devices are arranged along a acable that forms a closed loop

Data Transfer:

• Data transmitted on a ring network travels from one device to another around the entire ring in one direction
• When a device sends data, the data travels to each computer on the ring until it reaches its destination

Advantages:

• Can span a larger network than a bus network
• Cable faults are easily located, making troubleshooting easier
• The transmission of data is relatively simple as data travels in one direction only

Disadvantages:

• More difficult to install compared to bus network
• Failure of any cable or node will affect the operation of the entire network
• Slower data transmission as the data sent will go through all the nodes

STAR TOPOLOGY

Layout:

• All computers and devices are connected to a central device (hub or switch)
• Hub or switch are devices that provide a common central connection point for nodes on the network

Data Transfer:

• All data that transfer from one node to another passes through the hub or switch
• The hub takes a signal that comes from any device and passes it to other devices in the network

Advantages:

• Failure of one node will not affect the entire network
• Devices can be added to or removed from the network with little or no disruption to the network
• Easy to identify problems, making troubleshooting easier

Disadvantages:

• Failure of hub or switch will shut down the entire network
• Requires more cable than the other topologies
• More expensive due to the cost of the hub/switch