OSI Model Layers: Functions and Protocols for Network Communication

Application Layer

contains protocols used for process-to-process communications.

Presentation Layer

provides for common representation of the data transferred between application layer services.

Session Layer

provides services to the presentation layer to organize its dialogue and to manage data exchange.

Transport Layer

defines services to segment, transfer, and reassemble the data for individual communications between the end devices.

Network Layer

provides services to exchange the individual pieces of data over the network between identified end devices.

Data Link Layer

protocols describe methods for exchanging data frames between devices over a common media.

Physical Layer

describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device.