Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.

OSI (Open Systems Interconnection) is a layered model for defining and building communication systems. It is defined by the ISO (International Organization for Standardization). The lower layers define physical components and transmission schemes, the middle layers define communication management routines, and the upper layers define how applications connect into the model.

The presentation layer is layer 6 in the protocol stack, just below the top-level application layer and above the session layer. The presentation layer provides translation of data, defines data formatting, and provides syntax. The presentation layer prepares incoming data for the application layer, where the user views the data. For outgoing data, the presentation layer translates data from the application layer into a form that is suitable for transfer over the network. There are various encoding rules built into the presentation layer protocols that handle all the data translations.

Copyright (c) 2001 Tom Sheldon and Big Sur Multimedia.
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