Relationship between network level protocols and Structural Systems

The relationship between the network level protocol and the structure system between the LAN and the Internet communication is completed with the support of different network levels and network level protocols. So what are their definitions and functions? How can we locate the protocol, structure, system, and hierarchy? Next, let's take a few more details. 1. Several Basic concepts in a hierarchical architecture (1) Protocol is a communication Protocol. For example, in the postal communication system, the writing format, the envelope standard and the writing format, the packaging of letters, and the conventions on the album art of the mail are the communication regulations of the postal communication system. Therefore, in the process of computer network communication, in order to ensure accurate data communication between computers, a set of communication rules must also be developed, which is the communication protocol. Www.2cto.com (2) Layer is the basic method for people to deal with complex problems. When people encounter a complex problem, they are often used to breaking it down into several small problems and processing them one by one. For example, for the postal communication system, the solution is as follows: allocate a large number of functions to be implemented in different layers; Clearly define the process of implementing services and services at each level; and divide systems in different regions into the same level; different systems have the same functions at the same layer. When a high level uses services provided by the lower layer, it does not need to know the specific implementation method of the lower layer services.
There are many similarities between the hierarchical architecture used by the postal communication system and the computer network architecture. Its essence is the "divide and conquer" structured processing method for complex problems. The hierarchical processing method can greatly reduce the difficulty of problem handling, which is the direct motive force for adopting hierarchical structures in network research. Therefore, layers are another important and basic concept in the computer network architecture. Www.2cto.com (3) Interface is the connection point for information exchange between adjacent layers within the same node. For example, in the postal communication system, the mailbox is the interface specified between the sender and the postman. There are clearly defined interfaces between adjacent layers of the same node, and the lower layer provides services to the upper layer through interfaces. As long as the interface conditions remain unchanged and the underlying functions remain unchanged, changes in the implementation methods and technologies of the underlying functions will not affect the work of the entire system. Therefore, interfaces are also an important and basic concept in computer network implementation technology.
2. Network Architecture network protocols are indispensable for computer networks. A fully functional computer network requires a complete set of complex protocols. The best way to organize complex network protocols is the hierarchical structure model. Therefore, a set of Network hierarchy models and Network hierarchy protocols is defined as a Network Architecture ). The Network Architecture precisely defines the functions that a computer network should implement. What kind of hardware and software are used to implement these functions. The architecture is abstract, while the implementation is specific. It refers to some hardware and software that can run.
3. research Significance of Network Architecture in 1974, IBM proposed the world's first Network Architecture SNA (System Network Architecture), after which all devices that follow the SNA structure can be easily interconnected. As a result, various companies have launched their own network architecture, such as Digital companies' DNA. These network architectures all adopt the "layer" technology, and the Division, functions, and technical terms of each layer are different. Therefore, the computer network uses a layered structure, which has the following advantages: the layers of www.2cto.com are independent of each other. The upper layer does not need to know how the lower layer is implemented, but only needs to know the services provided by the layer through the interface between layers. Good flexibility. When any layer changes, for example, the implementation of technological changes due to technological advances, as long as the interface remains unchanged, the layers above or below will not be affected. In addition, you can even cancel a layer when the services provided by a layer are no longer needed. Because each layer is independent, you can select the most appropriate implementation technology for each layer. Changes in implementation technology at each layer will not affect other layers. Easy to implement and maintain. The entire system is divided into multiple small parts that are easy to implement and maintain, making it easy to implement, manage, and maintain the entire large and complex system. It is beneficial to the realization of standardization. Since each layer is clearly defined, that is, the functions and services provided by each layer are clearly defined, it is very conducive to the implementation of standardization. With the development of information technology, the interconnection of various computer systems and various computer networks has become an urgent issue. OSI reference models and network level protocols are proposed and researched in this context. This article is from the China IT lab