The OSI open system interconnection model is a reference model proposed by the 1984 International Standardization Organization (ISO). This model is a conceptual standard framework for network communication, making communication on the network formed by different manufacturers and application software. Now this model has become a major structural model for communication between computers and between networks. Most network communication protocols currently used are based on the structure of the OSI model. OSI is defined as a seven floors, which is to divide the task of the activity information in the network computer into seven smaller and easier handling task groups. A task or task group is assigned to an OSI layer. Each layer exists alone, so the task assigned to each layer can be executed independently. This allows the solution provided by one layer to be updated without affecting other layers.
Each layer of the OSI seven layer model has a clear feature. Basically, the communication between the seventh to the fourth layer process the first-end data source and destination address, while the third to the first layer processes communication between network devices,. On the other hand, seven layers of the OSI model can be divided into two groups: the upper layer (layer 7, layers 6, and layer 5) and the lower layer (layer 4, layers 3, layers 2, and layer 1). The upper layer processing of the OSI model is applied and implemented on the software. The highest layer, that is, the application layer is closest to the end user. The lower layer of the OSI model is to process data transmission. The information on the physical layer and the data link layer is executed on hardware and software. The most underlying, that is, the physical layer is closest to physical network media (such as, wire) and is responsible for replacing data on the medium.
The specific description of each layer is as follows: For details, please visit the following page: 中文 版: http://www.networkDictionary.com/chinese/protocols/model.php English version: http://www.networkDictionary.com/protocols/model .php
