A level revision

Bus, ring and star network topologies

A network topology describes a network's layout and arrangement, the way in which the computers and hardware (printers, scanners, etc), known as nodes, are all linked together. There are 3 key network topologies each of which have their own advantages and disadvantages.

Bus topology

The type of network topology is where all the nodes of the network are connected to a central line. All data transmitted between nodes goes through the central cable.

Advantages

• Easy to add and remove nodes
• Requires small amount of cable compared to other topologies so is less expensive and easier to setup and troubleshoot.

Disadvantages

• A failure in the central line means the whole network will go down.
• Only one route for data to take so will performance will decrease as more data is transmitted.

Ring topology

In a ring topology all the nodes are connected together in a loop. Data is transmitted from node to node in a single direction.

Advantages

• As all the data can only travel in one direction the transmission of messages is simple and high rates can be achieved.
• There is no dependence or need of a central computer or mainframe.

Disadvantages

• If on node or line fails then data cannot continue to be transmitted between all the rest of the nodes in the network.
• Harder to add new nodes into the system, requires the network to be disrupted.

Star topology

In the star network topology each node is connected directly to a central computer or mainframe.

Advantages

• More secure connection as data is sent directly between nodes (unlike ring networks)
• A failure of the cable will only affect one node, hence faults are easier to pinpoint.
• Easy to add new nodes without any disruption

Disadvantages

• Requires and is dependant upon a central computer.
• Requires more cable and is therefore more expensive to setup.