Network Models

NETWORK MODELS

What are network models and why should we know them ?

There are basically 2 types of network models 

1. OSI Network Model proposed by International Organization for Standardization.

2. DoD Network Model defined by Department of Defense, more commonly known as TCP/IP model.

These models will give us the insight into the different aspects of network, such as establishing, maintenance of sessions for communication between 2 different hosts, etc. This is achieved by sub-dividing the communication into different layers based on the services that is carried at each layer. There are subtle differences between these two models eventhough they follow the layered architecture for defining the communication.

Earlier, the network equipments were vendor specific, i.e. Vendor 'A' products were compatible with his own products. An organization has to purchase every equipment from one manufacturer, it cannot change the vendor. If it wanted to purchase from a new manufacturer then it needs to change its entire network equipments and purchase all the products from one manufacturer. 

By defining these models the industry could define some standards for each network equipment so that a compatibility between different manufactured equipments. Let us see how these models helped in achieving this major breakthrough.