Hierarchy of computer network protocols

We all know the principles of computer network protocols. In this regard, the hierarchy of computer network protocols has always been the focus of our learning. Then we will give a detailed explanation of its hierarchy based on the illustration below. The benefit of a hierarchy is that each layer implements a relatively independent function. A hierarchy also facilitates communication, understanding, and standardization) it is a set of various layers of computer networks and their Protocols. The hierarchy is generally expressed in a Vertical Layered Model (figure 1 )｡

Figure 1 hierarchical model of computer network protocol

Key points of the hierarchy:

1) In addition to physical media, all other peer entities perform virtual communication ｡

2) virtual communication at the peer layer must follow the protocol at the layer ｡

3) layer-n virtual communication is implemented through services provided by layer-n-n-1 at the layer-n interface and communication between layer-n-1 (usually virtual communication ｡

Principles of hierarchy Division:

1) The functions of each layer should be clear and independent from each other. When a specific implementation method of a layer is updated, as long as the interfaces of the upper and lower layers remain unchanged, this will not affect the neighbors ｡

2) the interface between layers must be clear and the amount of information crossing interfaces should be as small as possible ｡

3) the number of layers should be moderate. If the number of layers is too small, the computer network protocol for each layer is too complex. If the number of layers is too large, the architecture is too complex, it makes it difficult to describe and implement functions at different layers ｡

The architecture of the network is characterized:

1) Use functions as the basis for hierarchy ｡

2) entities at Layer n can only use the services provided at Layer n-1 to implement their own defined functions ｡

3) When layer n provides services to layer n + 1, this service not only includes functions of layer n, but also functions provided by lower-layer services ｡

4) Only interfaces are available between adjacent layers, and the specific implementation details of the provided services are completely blocked from the previous layer ｡