Bus Topology

In a bus topology, devices share a common backbone cable to send and receive data. A thick co-axial cable is used to connect all devices. Bus topology uses daisy chain scheme to add more devices in a network. In the daisy chain scheme, device 1 is connected to device 2; device 2 is connected to device 3. The first and last devices are connected to 50 ohm terminator resistor.

Basic Structure of Bus Topology

In bus topology, the server is connected at one end of the backbone cable and the other devices are connected at different positions along the backbone cable known as trunk. Terminator is placed at each end of the cable. It is used to remove unsent data from the cable if the destination device is faulty. Data is sent to all the devices along the cable. As the message arrives at each device, it checks the destination address, encoded in the message. If the address matches, it accepts the data. If the address does not match, the device ignores the data. At a time, only one device can send data. Due to this a number of devices waiting to send data on the bus are more. This results in slowing down the performance of a network.

In Bus Topology, the devices are not responsible for data transmission from one device to another. They can only listen to the information sent on a network. If one device fails, it does not affect the entire network. In an active topology, devices regenerate signals and take part in transfer of data; hence if one device fails then the entire network is affected.

Every device on a network shares a common cable. When two machines transmit data at the same time the signal collide. Due to this, the information is destroyed. This process is called Collision. Collision can affect the performance of the network.

Advantages and Disadvantages of Bus Topology

Bus Topology is also called as a linear bus. It is the simplest and most common method of computer networking. However bus networks work best with a limited number of devices.

Advatanges of bus topology are:

• Easy to connect a device to linear bus

• Requires less cable as compared to star topology

• Less expensive than other topologies

• Works better for smaller networks

Disadvantages of bus topology are:

• Entire network gets affected if there is a break in the main cable

• Terminators are required at both ends of the backbone cable

• Difficult to detect the faulty device.

• Limited number of devices can be attached

• Heavy traffic and addition of devices degrades the performance

• Expensive than single node topology

You may also be interested in

Single Node Topology

Star Topology

Ring Topology

Mesh Topology

Tree Topology vs. Hybrid Topology