Computer Studies 7010 Presentation Section 5 OSIMODELS ad

Computer Studies (7010) Presentation Section 5 OSI-MODELS ad A m ham u : M O-2 B r o t ss : sen a e l r C P lah l u bd

ISO and The OSI Model [History] International standard organization (ISO) established a committee in 1977 to develop an architecture for computer communication. Open Systems Interconnection (OSI) reference model is the result of this effort. In 1984, the Open Systems Interconnection (OSI) reference model was approved as an international standard for communications architecture. Term “open” denotes the ability to connect any two systems which conform to the reference model and associated standards.

OSI Reference Model: Two problems have the origin of OSI these were: The duplication of Equipment Resources In ability to communicate Effectively The term used to describe how information or data makes its way from application programmes (such as spreadsheets) through a network medium (such as wire) to another application programme located on another network is OSI. The OSI reference model divides the problem of moving information between computers over a network medium into SEVEN smaller and more manageable problems. This division is usually referred to as LAYERING

Purpose of OSI Model n n It breaks network communication into simpler and smaller parts so that it is easy to understand them. It breaks network communication into simpler and smaller parts so that it is easy to built up a communication. Allows different types of hardwares and softwares to communicate with each other more efficiently. Prevents the effect of changing in one layer to another.

OSI model [Layering]

Functions n n Application: The processes of application programs are being dealt in this layer. Presentation: This layer is responsible fro the presentation of data.