Network Topologies

Network Topologies

It is the arrangement of computers, cables, and other components on a network or a map of the geometrical shape of the physical network of computers.

Types of Network Topologies

  • Bus topology
  • Star topology
  • Ring topology
  • Mesh topology
  • Tree topology
  • Hybrid topology

Bus topology

A bus topology connects each computer to a segment called the trunk. It consists of a main cable with terminators at both ends.

Advantages

  • Easier to implement and extend.
  • Least amount of cable is required.
  • Failure of one computer (node) doesn’t affect other.

Disadvantages

  • Difficult to troubleshoot.
  • If a cable breaks in any condition, entire network will breakdown.
  • Data traffic is high, which increases data collision rate.

Star topology

Most common network topology where each computer is connected to the central device such as a hub. Data passes through the hub before reaching the destination. Hub amplifies the data signals and broadcasts them.

Advantages

  • Easier to add or remove computers.
  • Easier to monitor and troubleshoot.
  • Failure of one computer doesn’t affect entire network.

Disadvantages

  • Failure on hub affects all nodes.
  • Each computer requires dedicated cable so; more cable is required.
  • Performance depends on hub capacity.

Ring topology

In this topology, each node is connected to the network in a closed loop/ring. Data is transmitted in only one direction (either clockwise or anticlockwise).

Advantages

  • The growth of system has minimal impact on performance.
  • Data traffic is reduced as data flows in only one direction.
  • Easy to trobuleshoot.

Disadvantages

  • Failure of a computer affects the entire network.
  • Less felxible, difficulty in adding and removing the computers.

Mesh topology

In this topology, every device has point-to-point link to every other devices.

Advantages

  • Good fault tolerance due to the dedicated path for each node.
  • If a node fails, other alternatives are present in the network.
  • No traffic problems on the channels.

Disadvantages

  • Very high cabling required.
  • Installation and maintenance are very difficult.

Tree topology

Tree topology consists of a root node, and all other nodes are connected to it, forming a hierarchy. It is also called hierarchical topology.

Advantages

  • Expansion of nodes is possible and easy.
  • Error detection is easy.
  • Other nodes are unaffected if one segment is damaged.

Disadvantages

  • Very high cabling required.
  • Maintenance is difficult if more nodes are added.
  • If the main cable collapses, the whole network will also collapse.

Hybrid topology

Hybrid topology is the combination of two or more differnt types of topologies. It is design to reduce pros and cons of different topologies. E.g., Star-Ring hybrid topology, Star-Bus topology or any other combinations.