Also known as the Open System Interconnection Reference Model, the OSI Model was created as one of the features of the Open Systems Interconnection initiative, which segregates a computer network into several layers including the Presentation, Transport, Physical and Data Layers. The layers of this model provide important services such as error-free communications, subnetwork access and data transport. In order to use this model effectively and easily, it is important to have a sufficient background on the functions and design of each layer of OSI.
The History of the OSI Model
The initiative for the development of the OSI framework architecture began in 1978 by the International Organization for Standardization (ISO). It is consisted of two elements namely, a group of protocols and the Basic Reference Model. The inclusion of protocols is important to the interaction of entities in two different hosts. The concept behind the development of the architecture was inspired by the work of Honeywell computer scientist Charles Bachman. However, through time, the design of the layers of the OSI model has evolved from experienced associated with several network models such as the CYCLADES network. The design that computer experts use today was featured in ISO 7498.
The Different Layers of the OSI Model
The OSI Model that computer scientists use in present times is composed of seven layers, which are important to the efficient and proper implementation of software and hardware. Each layer of the framework is essential to the functionality of the other layers. The first four layers of the model are called the Physical Layer, Data Link Layer, Network Layer, and the Transport Layer. The remaining layers are known as the Session Layer, the Presentation Layer and the Application Layer. The basic functions of this framework include the transfer of data sequences, error control, flow control as well as segmentation and desegmentation. Aside from these purposes, the layers are also important to control the unauthorized interactions among the devices that are connected in a particular computer network. Moreover, they are essential to determine the availability of resources and the identification of communication partners.
Additional Information and Other Important Details
The OSI Model features various protocol standards that are developed and used by different organizations such as the American National Standards Institute (ANSI), the Institute of Electrical and Electronic Engineers (IEEE) and the International Telecommunications Union (ITU). The layered approach used for the development of this model has several advantages, which include modular engineering, improved teaching and learning, accelerated advancement and reduced intricacy.