TCP/IP model
The TCP/IP reference model is the reference model for computer network grandfather ARPANET and subsequent Internet use. ARPANET is a research network sponsored by the u.s.department of Defense. Gradually it connected hundreds of universities and government departments through leased telephone lines. With the advent of wireless networks and satellites, existing protocols had problems connecting to them, so a new reference architecture was needed. This architecture is known as the TCP/IP reference model after the emergence of its two major protocols.
Four-layer protocol
TCP/IP is a set of communication protocols used to interconnect networks. The Internet network architecture takes TCP/IP as the core. The TCP/IP-based reference model divides the protocol into four layers: the network access layer, the Internet layer, the transport layer (host-to-host), and the application layer.
TCP/IP is a set of communication protocols used to interconnect networks. The Internet network architecture takes TCP/IP as the core. The TCP/IP-based reference model divides the protocol into four layers: the network access layer, the Internet layer, the transport layer (host-to-host), and the application layer.
The application layer
The application layer corresponds to the higher layers of the OSI reference model, providing users with various services they need, such as FTP, Telnet, DNS, SMTP, and so on.
The transport layer
Corresponding to the transport layer of the OSI reference model, the transport layer provides end-to-end communication functions for application-layer entities, ensuring the sequential transmission of packets and data integrity. This layer defines two major protocols: the transport control protocol (TCP) and the user datagram protocol (UDP).
TCP protocol provides a reliable data transmission service-connected by "three handshakes". UDP provides unreliable (not unreliable), connectionless data transfer services.
Internet layer
The Internet layer corresponds to the OSI reference model's network layer, which mainly solves host-to-host communication problems. It contains protocol design packets for logical transmission across the network. Focus on giving the host an IP address to complete the addressing of the host, it is also responsible for the routing of packets in a variety of networks. This layer has three main protocols: Internet protocol (IP), Internet group management protocol (IGMP), and Internet control message protocol (ICMP).
IP protocol is the most important protocol in the Internet layer. It provides a reliable and connectionless datagram delivery service.
Network access layer (i.e. Host-network layer)
The network access layer corresponds to the physical layer and data link layer in the OSI reference model. It monitors the exchange of data between the host and the network. In fact, TCP/IP itself does not define the protocol for this layer. Instead, each network participating in the interconnection USES its own physical layer and data link layer protocols and then connects to the TCP/IP network access layer. Address resolution protocol (ARP) works at this layer, the OSI reference model's data link layer.
