OSI seven layer protocol model, TCP/IP four-tier model learning notes

1. Relationship between the OSI seven layer and the TCP/IP four layer

1.1 OSI introduces the concepts of services, interfaces, protocols, and hierarchies, and TCP/IP builds the TCP/IP model using these concepts from OSI.

1.2 OSI first has the model, then has the agreement, first has the standard, then carries on the practice, but the TCP/IP is opposite, first has the protocol and the application to propose the model again, and is the reference OSI model.

1.3 OSI is a theoretical model, and TCP/IP has been widely used as a de facto standard for network interconnection.

Tcp:transmission Control Protocol Transmission Protocol

Udp:user Data Protocol User Datagram Protocol

OSI Layer Seven Network model	TCP/IP four-layer conceptual model	Corresponding network protocol
Application Layer (application)	Application Layer	HTTP, TFTP, FTP, NFS, WAIS, SMTP
Presentation Layer (Presentation)	Telnet, Rlogin, SNMP, Gopher
Conversation Layer (session)	SMTP, DNS
Transport Layer (Transport)	Transport Layer	TCP, UDP
Networking Layer (Network)	Network layer	IP, ICMP, ARP, RARP, AKP, UUCP
Data Link Layer	Data Link Layer	FDDI, Ethernet, Arpanet, PDN, SLIP, PPP
Physical Layer (physical)	IEEE 802.1A, IEEE 802.2 to IEEE 802.11

2. OSI Seven layer protocol model

Seven-layer structure memory method: should, table, meeting, transmission, net, number, object

The application layer protocol needs to be mastered: HTTP (Hyper Text Transfer Protocol), FTP (File Transfer Protocol), SMTP (Simple Mail transfer rotocol), POP3 (Post Office Protocol 3), IMAP4 (Internet Mail Access Protocol)

3. TCP/IP four-tier model

3.1 Application layer: Corresponds to the application layer, presentation layer, and Session layer in the OSI

3.2 Physical link layer: corresponds to the data link layer, the physical layer (also called the Network Interface layer) in the OSI

3.3 Description of the packet:

The IP layer transmission unit is the IP packet, belongs to the point-to-point transmission; TCP Layer transmission unit is TCP segment, which belongs to end-to-end transmission