The OSI or Open Systems Interconnection model is a conceptual framework used to understand and implement network communications by dividing the process into seven distinct layers. Each layer serves a specific function and interacts with the layers directly above and below it. This model helps standardize networking protocols and facilitates interoperability between different systems and technologies.
The process of data transmission begins at the topmost layer (Layer 7 - Application Layer) and moves down through each layer to the bottommost layer (Layer 1 - Physical Layer) before being transmitted over the physical medium. Upon reaching the destination, the data moves back up through the layers in reverse order, with each layer processing the data as needed.
This model is widely used in networking and telecommunications to design and troubleshoot network systems, ensuring that different hardware and software components can work together effectively. The standard is maintained by the International Organization for Standardization (ISO) with the most recent update in 1994. Together with the TCP/IP model, the OSI model forms the foundation for modern networking, guiding the development of protocols and technologies that enable global communication and data exchange.
To the left is a visual representation of the OSI model. Click on any layer to learn more about its function and role in networking.