OSI model and TCP/IP model

Reasons for the existence of the OSI model (open System interconnection):

The network model is built so that the builders of the network can build networks that can communicate and work with each other, and describe the transmission of data from one computer to another on a network.

1.physical Layer

Defines the electronic and functional aspects of the connection between the end systems, including voltage levels, physical distances, transmission rates, and cycles of voltage changes.

2.data link Layer

Provides the ability to rely on physical links for data transfer, including physical addressing, network topology, network access, and flow control.

3.network Layer

When routing is required, network addressing and path selection are provided.

4.transport Layer

Data is divided into data streams, which are responsible for network communication between terminals.

5.session Layer

Responsible for exchanging data between entities in the presentation layer.

6.presentation Layer

Focus on the data structure to ensure that it is understood and is responsible for compressing and decompressing.

7.application Layer

The closest to the user, to provide Internet services to the user application.

TCP/IP Model:

1.application Layer

Handles high-level protocol, presentation, coding, and session control issues, and ensures that the data is properly packaged.

2.transport Layer

Tcp:transmission Control Protocol

Udp:user Datagram Protocol

The format of the data is segement

3.Internet Layer

Independent of path and network, function is path selection and message exchange, IP protocol.

4.network Access Layer

Care about all the issues that IP packets exchange on the physical link, Lan,wan technology.

Comparison:

1. Both have layers, and network experts need to know both.

2. Both have application, although they include different services.

3. There are transport and network layers.

4. Message exchange technology is the default.

The 5.TCP/IP model looks simpler because there are fewer layers.

The 6.TCP/IP model is a network-established standard, so the TCP/IP model is recognized only because of the protocol. Most networks are built on the TCP/IP model, although the OSI model is generally used as a guideline.

OSI model and TCP/IP model