What architecture does a computer network system use?

The architecture adopted by the computer network system is: OSI's seven-layer protocol architecture, TCP/IP's four-layer protocol and five-layer protocol architecture; which is the hierarchical division of network protocols and the structure of each layer of protocols. Sets, protocols in the same layer are determined according to the functions to be achieved by the layer.

The architecture adopted by the computer network system is:

There are three architectures

1. OSI's seven-layer protocol architecture

OSI is a standard formulated by the International Organization for Standardization. It has a clear concept and complete theory, but is complicated and impractical.

OSI architecture

7 Application layer

6 Presentation layer

5 Session layer

4 Transport layer

3 Network layer

2 Data link layer

1 Physical layer

2, TCP/IP four-layer protocol

TCP/IP architecture has been widely used.

TCP/IP architecture

4 Application layer (various application layer protocols such as FTP, DNS, etc.)

3 Transport layer (TCP or UDP)

2 Internet layer (also known as network interconnection layer)

1 Data link layer (also known as network interface layer)

3. It has five layers The architecture of the protocol

The architecture when learning network principles, combining the advantages of OSI and TCP/IP.

5 Application layer

4 Transport layer

3 Network layer

2 Data link layer

1 Physical layer

(5) Application layer

The application layer directly provides services for the user's application process.

Application layer protocols: FTP, DNS, HTTP and other protocols.

(4) Transport layer

The transport layer is responsible for providing services for communication between processes in two hosts.

Protocol used by the transport layer:

1>Transmission Control Protocol TCP

Connection-oriented, the data transmission unit is a message segment, providing reliable delivery.

2>User Datagram Protocol UDP

Connectionless, the data transmission unit is datagram, and reliable delivery is not guaranteed.                 

(3) Network layer (using IP protocol)

The network layer is responsible for providing communication services for different hosts on the packet-switched network.

Tasks of the network layer:

When sending data, the network layer encapsulates the message segments or user datagrams generated by the transport layer into packets (also known as IP datagrams) for transmission. Another task of the network layer is to select appropriate routes so that the packets passed by the transport layer of the source host can find the destination host through the routers in the network.

(2) Data link layer

When transmitting data between two adjacent nodes (host and router or between two routers), the data link layer combines the network layer The submitted IP datagram is assembled into a frame, and the data in the frame is transmitted on the link between two adjacent nodes.

(1)Physical layer

The physical layer is used to transmit bit streams.

Transmission uses some physical media: twisted pair, optical fiber, etc.

(1). Each layer is independent. A certain layer does not need to know how its next layer is implemented, it only needs to call the interface between layers. (2), good flexibility. Changing any one of these layers will not affect the other layers as long as the interface remains the same.

(3), easy to implement and maintain.

(4), can promote standardization work. The function of each layer is precisely explained.

The computer network architecture is a hierarchical division of network protocols and a collection of protocols at each layer. The protocols in the same layer are based on the requirements of that layer. Determine the functions implemented. The protocol functions between each peer layer are completed by the corresponding underlying services.

The computer network is a very complex system. In order to design complex computer networks, people adopt a layered approach to convert large and complex problems into several small local problems.

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