TCP/IP structure corresponds to OSI

The TCP/IP structure corresponds to the abbreviation of OSI Transmission Control Protocol/Internet Protocol, it is the most basic protocol of the Internet and the basis of the Internet international network. It consists of the IP protocol at the network layer and the TCP protocol at the transmission layer. TCP/IP defines how electronic devices connect to the Internet and how data is transmitted between them. The protocol uses a layer-4 hierarchy. Each layer calls the network provided by its next layer to meet its own needs. In layman's terms: TCP is responsible for discovering transmission problems. When there is a problem, it sends a signal and requires a re-transmission until all data is securely and correctly transmitted to the destination. The IP address specifies an address for each computer on the Internet. The TCP/IP protocol is not the combination of the TCP/IP protocol and the IP protocol, but the entire TCP/IP protocol family of the Internet. In terms of protocol layered model, TCP/IP consists of four layers: network interface layer, network layer, transmission layer, and application layer. The TCP/IP protocol does not fully comply with the OSI Layer-7 Reference Model. OSI (Open System Interconnect) is a traditional reference model for Open System Interconnection, it is a layer-7 abstract reference model for communication protocols, where each layer executes a specific task. This model aims to make various hardware communicate with each other at the same level. These seven layers are: physical layer, data link layer (network interface layer), network layer (network layer), transmission layer, Session Layer, presentation layer and application layer (Application Layer ). The TCP/IP communication protocol uses a layer-4 hierarchy. Each layer calls the network provided by its next layer to meet its own needs. ARPANET designers focus on network interconnection and allow the Communication Subnet (Network Interface Layer) to use existing or future protocols. Therefore, no special protocols are provided at this layer. In fact, TCP/IP can be connected to any network through the network interface layer, such as X.25 or IEEE802 LAN. The TCP/IP structure corresponds to the layer functions in OSIOSI. the TCP/IP protocol family applies to file transmission, email, file service, virtual terminal TFTP, HTTP, SNMP, FTP, SMTP, DNS, telnet, etc. Presentation Layer translation, encryption, compression, no protocol Session Layer dialog control, establishment of synchronization points (resume), no protocol Transport Layer port addressing, segment restructuring, traffic, error control TCP, UDP network layer logical addressing, Route Selection IP, ICMP, OSPF, OSPF, IGMP, RIP data link layer frame formation, physical addressing, traffic, error, access control SLIP, CSLIP, PPP, MTU, ARP and RARP physical layer are used to set the network topology, bit transmission, and Bit Synchronization ISO2110, IEEE802, and 802.2. Note that tcp itself does not have the error detection function caused by noise in data transmission, however, timeout error retransmission is implemented.