The development of the OSI model started in the late 1970s to support the emergence of the diverse computer networking methods that were competing for application in the large national networking efforts in the world … See more

The recommendation X.200 describes seven layers, labelled 1 to 7. Layer 1 is the lowest layer in this model.
Layer 1: Physical layer See more

Neither the OSI Reference Model, nor any OSI protocol specifications, outline any programming interfaces, other than deliberately abstract service descriptions. Protocol … See more

• Government Open Systems Interconnection Profile
• Hierarchical internetworking model
• History of the Internet
• See more

Communication protocols enable an entity in one host to interact with a corresponding entity at the same layer in another host. … See more

Cross-layer functions are services that are not tied to a given layer, but may affect more than one layer. Some orthogonal aspects, such as management and security, … See more

The table below presents a list of OSI layers, the original OSI protocols, and some approximate modern matches. This correspondence is rough: the OSI model contains idiosyncrasies not found in later systems such as the IP stack in modern Internet. See more