Reference Models in Computer Network

In computer networks, reference models give a conceptual framework that standardizes communication between heterogeneous networks.

The two popular reference models are −

• OSI Model
• TCP/IP Protocol Suite

OSI Model

OSI or Open System Interconnection model was developed by International Standards Organization (ISO). It gives a layered networking framework that conceptualizes how communication should be done between heterogeneous systems. It has seven interconnected layers.

The seven layers of the OSI Model are a physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer. The hierarchy is depicted in the following figure −

TCP / IP PROTOCOL SUITE

TCP stands for Transmission Control Protocol, while IP stands for Internet Protocol. It is a suite of protocols for communication structured in four layers. It can be used for communication over the internet as well as for private networks.

The four layers are application layer, transport layer, internet layer and network access layer, as depicted in the following diagram −