OSI represents Open System Interconnection. It was produced by the International Organization for Standardization (ISO) located in Geneva, Switzerland, and the consultative committee for international Telephone and Telegraph (CCITT).
OSI was created to develop a frequent standard of network structure throughout the globe. It supports a general idea of inter-process communication so that any open system can technically connect with another accessible framework without any issues. OSI model is a seven-layered architecture model.
The advantages of the OSI Model are as follows −
The OSI models clearly define the services, interfaces and protocols. It explains which layer's services are supported. It also explains how the procedures placed about a specific layer will create its services and how it can help the protocols to do their task.
The protocols of the ISO model are exceptionally private and can be returned with other appropriate protocols quickly.
It is a general model.
It provides connection-oriented and connectionless services.
Because of the layered architecture following the abstraction services, the change appearing in one layer does not force the others.
It gives more security and flexibility, unlike having all features accumulate together into an individual layer.
The disadvantages of the OSI Model are as follows −
Sessions and presentation layers are not of much use.
The OSI model was developed first, and then the protocols were created to conform to the network architecture requirements. Thus in real life, there is an issue of the proper protocol in the model.
The OSI layers are interdependent. OSI layers cannot operate in parallel. Each approaching layer requires waiting to get the data from its predecessor layer. For instance, the application layer gets the data from the presentation layer, and the presentation layer needs to wait to get the data from the session layer etc.
The performance of Transmission Control Protocol (TCP) and the Internet Protocol (IP) TCP/IP protocols was earlier the release of this model, and thus some organizations are uncertain about using it.
A few layers, such as the presentation layer and session layer, have very few services when virtually set up.