Network Classification by Network Topology

Welcome everyone!
Following my last blog post on Network Classification based on Functional Relationships of Networks around us, is today's blog over Network Classification on the basis of their topology.

To classify networks on the basis of topology, first we have to understand what topology is.  
Topology is "the way in which constituent parts are interrelated or arranged". 

Computer Networks can be arranged in a variety of ways, each way presenting its own advantages and disadvantages. These arrangements form the basis of classification of networks on the basis of topology as we'll see now. 

Network Classification by Network Topology

1. Bus Network
2. Star Network
3. Ring Network
4. Mesh Network
5. Tree Network

Let us now study them in detail. 

Bus Network

Bus Network Topology

Bus networks use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message. 
The following diagram showcases the various advantages and disadvantages of a Bus Network Topology.

 

 

Star Network

Star Network Topology

In its simplest form, a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages. This consists of a central node, to which all other nodes are connected; this central node provides a common connection point for all nodes through a hub. In star topology, every node (computer workstation or any other peripheral) is connected to a central node. Thus, the central node and leaf nodes, and the transmission lines between them, form a graph with the topology of a star.

The following diagram showcases the various advantages and disadvantages of a Star Network Topology.

 

Ring Network

Ring Network Topology

In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counter-clockwise"). A failure in any cable or device breaks the loop and can take down the entire network. 

The following diagram showcases the various advantages and disadvantages of a Ring Network Topology.

 

Mesh Network

Mesh Network Topology

Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing. A mesh network in which every device connects to every other is called a full mesh. Also partial mesh networks also exist in which some devices connect only indirectly to others.

The following diagram showcases the various advantages and disadvantages of a Mesh Network Topology.

Tree Network

Tree Network Topology

Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus and each hub functions as the root of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.  The following diagram showcases the various advantages and disadvantages of a Tree Network Topology.

As we have finished the analysis of each of the basic Topologies, I want to tell you that as practically innumerable networks exist, also do practically innumerable network topologies. The ones we have studied are the very basic ones and very often is the case when a Hybrid of these topologies is practically maintained so as to extract the advantages of different topologies. With this, lets finally look at the diagrammatic representation of the different Network Topology Models together to review our knowledge about them.

Network Topologies

Now I'd advise you to read our general article on Computer Network Classification to even further enhance your knowledge and have an overview of the topic. Take care till then :)