What is Bus Topology
The bus topology connects all the nodes on a network to a main cable called bus, as shown in the following figure
In the preceding figure Computers are connected through the bus, When a Computer needs to transmit data to an another computer , Is sends the data over the bus in the form of data packets. In the bus topology each packet placed on the bus contains the address of the destination node. The packet is transmitted in both directions along the bus. In other words,The data packet is sent to all the nodes in the network.Each node on the network, which receive a data packet compares the destination address of the packet with its own address. If the two address match the nodes, reads the data packet else it ignore the packet.
A device call Terminator is attached to each end of the bus As the name suggest , the terminator receives signal that have traversed through the bus and terminates them.The termination of signals ensures that signals that have already traversed through the bus do not collide with new signals.
In the Bus topology data packets may collide if multiple nodes transmit signal at the same time. to prevent this situation, the bus topology provides a collision detection mechanism called Carrier Sense Multiple Access with Collition Ditection (CSMA/CD) . This Mechanism resolves the collisions that may occur if multiple nodes transmit data packet simultaneously.
Inability to handle high network traffic
In the preceding figure Computers are connected through the bus, When a Computer needs to transmit data to an another computer , Is sends the data over the bus in the form of data packets. In the bus topology each packet placed on the bus contains the address of the destination node. The packet is transmitted in both directions along the bus. In other words,The data packet is sent to all the nodes in the network.Each node on the network, which receive a data packet compares the destination address of the packet with its own address. If the two address match the nodes, reads the data packet else it ignore the packet.
A device call Terminator is attached to each end of the bus As the name suggest , the terminator receives signal that have traversed through the bus and terminates them.The termination of signals ensures that signals that have already traversed through the bus do not collide with new signals.
In the Bus topology data packets may collide if multiple nodes transmit signal at the same time. to prevent this situation, the bus topology provides a collision detection mechanism called Carrier Sense Multiple Access with Collition Ditection (CSMA/CD) . This Mechanism resolves the collisions that may occur if multiple nodes transmit data packet simultaneously.
Advantages
- Easy Installation
- Require Minimum cabling
- Relatively inexpensive
- Cost of cabling is less
Limitations
Low fault tolerance
- The Bus topology is highly prone to faults. If the bus connecting the computers malfunctions, the entire network communication is disrupted. As a result, the bus is single point of failure (SPOF) on the network
- In the bus topology, only one nod can transmit packets at any instance. If multiple nodes transmit data packets simultaneously, it leads to network collisions. As a result the higher the number of nodes on the bus, the lower is its performance. According to specifications,only 15 nodes can be connected to a bus of 30 meters.
- Adding nodes to an existing bus topology network is difficult.To add a node to the net work, the entire network cable setup needs to be reconfigured.I addition , the length of the cable used for the topology has a physical limitation of 30 meters.It cannot expanded beyond this limit. As as a result ,the number of nodes that can be attached to the network is limited.
- If a problem occurs on a node in the bus topology , troubleshooting become time-consuming. This is because the administrator needs to check every point on the step to locate the fault.
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