Network topology and its types

Computer Science

 What is Network Topology ?

Network topology refers to  to the manner in which the links and nodes of a network are arranged to relate to each other. It defines the way different nodes are placed and interconnected with each other.

Alternately, network topology may describe how the data is transferred between these nodes.

There are two types of network topologies:

 Physical

 Logical

 Physical topology emphasizes the physical layout of the connected devices and nodes,

while the logical topology focuses on the pattern of data transfer between network nodes.

The physical and logical network topologies of a network do not necessarily have to be identical.

However, both physical and network topologies can be categorized into five basic models:

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

Bus Topology: 

All the devices/nodes are connected sequentially to the same backbone or transmission line. This is a simple, low-cost topology, but its single point of failure presents a risk.

Star Topology:

All the nodes in the network are connected to a central device like a hub or switch via cables. Failure of individual nodes or cables does not necessarily create downtime in the network but the failure of a central device can. This topology is the most preferred and popular model.

Ring Topology:

All network devices are connected sequentially to a backbone as in bus topology except that the backbone ends at the starting node, forming a ring. Ring topology shares many of bus topology's disadvantages so its use is limited to networks that demand high throughput.

Tree Topology: 

A root node is connected to two or more sub-level nodes, which themselves are connected hierarchically to sub-level nodes. Physically, The tree topology is similar to bus and star topologies; the network backbone may have a bus topology, while the low-level nodes connect using star topology.

Mesh Topology: 

The topology in each node is directly connected to some or all the other nodes present in the network. This redundancy makes the network highly fault-tolerant but the escalated costs may limit this topology to highly critical networks.