TCP/IP reference Model and OSI reference Model

TCP/IP reference model OSI reference model

Application layer

Application layer

Presentation layer

Session layer

Transport layer

Transport layer

Internet layer

Network layer

Network interface layer

Data link layer

Physical layer

TCP/IP reference model:

The network interface layer is the interface between TCP/IP and various LAN or WAN.

There are four main protocols in the Internet layer: Internet Protocol (IP), address Resolution Protocol (ARP), reverse address Resolution Protocol (RARP) and Internet Control message Protocol (ICMP).

The two main protocols in the transport layer are Transmission Control Protocol (TCP) and user Datagram Protocol (UDP). TCP communication is established on the basis of connection-oriented, which usually requires three stages: establishing TCP connection, transmitting message segment, and removing TCP connection.

The main protocols in the application layer are: DNS, SNMP, TFTP (simple File transfer Protocol) are usually used in UDP, and HTTP, FTP, TELNET, SMTP are usually used in TCP protocol.

The same and different:

Both the OSI reference model and the TCP/IP reference model adopt the concept of hierarchical structure, but the former is a seven-tier model and the latter is a four-tier structure. The main differences are as follows:

1. Services, interfaces, and protocols

The concept of the OSI reference model is clear, and the three concepts and the relationship between them are clearly defined, while the TCP/IP reference model does not clearly distinguish between services, interfaces and protocols.

two。 Relationship between model and protocol

OSI is the first model, then the protocol (universal, but difficult to implement)

TCP/IP is the first protocol, then the model (practical, but not universal).

3. Connection-oriented and connectionless servic

The network layer of the OSI reference model provides both connection-oriented and connectionless services. But the transport layer only provides connection-oriented services.

The interconnection layer of the TCP/IP reference model provides only connectionless services, while the transport layer provides connection-oriented services (TCP) and connectionless services (UDP).