OSI Model

Layer # Name Mnemonic Encapsulation Units Devices or Components Keywords/Description
7 Application All data PC Network services for application processes, such as file, print, messaging, database services
6 Presentation People data Standard interface to data for the application layer. MIME encoding, data encryption, conversion, formatting, compression
5 Session Seem data Interhost communication. Establishes, manages and terminates connection between applications
4 Transport To segments End-to-end connections and reliability. Segmentation/desegmentation of data in proper sequence. Flow control
3 Network Need packets router Logical addressing and path determination. Routing. Reporting delivery errors
2 Data Link Data frames bridge, switch, NIC Physical addressing and access to media. Two sublayers: Logical Link Control (LLC) and Media Access Control (MAC)
1 Physical Processing bits repeater, hub, transciever Binary transmission signals and encoding. Layout of pins, voltages, cable specifications, modulation