subject: The 7 Layers of the OSI Model [print this page] The 7 Layers of the OSI Model The 7 Layers of the OSI Model
The OSI model was first introduced because of various efforts and research done on computing interconnectivity that began in 1978. Even though Al Gore prides himself as the pioneers and main creators of the internet, the foundation of modern computers and the online web has long been in development years before. OSI stands for Open Systems Interconnection, which is a two-pronged component framework which gives credit to Helen Yanulus of the Northampton Community College.
The OSI model features seven generic and vertically piled theoretic layers. Every layer gives data transmission function to the layer found either above or below it. Every layer also contains a set of standards, systems and protocols that will pass on data with relational bodies in other higher forms and layers. The following layer will rely on the layer found below it, so data cannot simply skip or jump layers. The internet focuses more on TCP/IP protocols that incorporates some aspects of the OSI model. The seven layers can also be deduced, following the statement that "All People Seem to Need Data Processing". This starts from the bottom layer moving upward.
The Physical and Data Layer
The physical layer describes the physical link systems for a certain network from the end user. This is also known as layer 1 which functions to relate the standards to networking plugs and cabling. It also features the voltages that can be set all over the network. The data layer or layer 2 functions to create the network. The system will manage the transmission of information between the existing networks. Switches and Hubs are located in layer 2.
The Network and Transport Layer
Layer 3 or the network layer is the final physical part of the network. The role of this layer is to manage the flow of information. Routers belong in this layer. The transport layer or layer 4 function to prepare the movement of data, in bytes and bits, through the existing network. Other relevant functions include checking and correction of errors and confirmation of deliveries.
The Session, Presentation and Application Layer
The final layers: session, presentation and application are the last 3 in the OSI model. The session layer or layer 5 functions by creating the connection or link between the destination and the sender, as soon as information is prepared. The connection is also known as a session, which brings about the name of this layer. As soon as the digital and physical pathways are set, the actual management will be done in this layer. Layer 6 or the presentation layer makes the data readable and understandable at the other end of the connection. The layer chooses the data syntax so it can effectively be interpreted by the receiver. In human terms, the function is similar to selecting the dialect or language when talking to another person.
The final layer, layer 7 or application layer is found at the top of the OSI model. This is used by the end user to interact. As soon as data is sent or acquired, it should be made applicable to the user. Included in the application layer is the platform where information will be created, acquired and displayed on the computer. This is the program that will make, acquire, interpret and display the information from the very beginning.
