The meaning and function of TCP/IP protocol analysis

The TCP/IP protocol model from a more practical point of view, the formation of an efficient four-tier architecture, namely, network interface layer, IP layer, Transport layer and application layer. TCP/IP is a set of specialized protocols, including IP, TCP, UDP, ARP, ICMP, and other protocols known as sub-protocols.       Network Interface layer: The network interface layer in the TCP/IP model corresponds to the physical layer of the OSI/RM, the data link layer, and a portion of the network layer. The TCP/IP reference model does not describe this layer specifically, it generally refers to a variety of computer networks, such as SatNet, ARPAnet, LAN, Packet Wireless network. The protocols used in this layer are mostly protocols inherent to each communication subnet, such as the Ethernet 802.3 protocol, Token Ring Network 802.5 protocol or packet switching network x.        IP layer, the Internet Protocol layer, also known as the internetwork Layer, the network interconnect layer. is a key part of the TCP/IP model. Its function is to enable the host to send the IP datagram (datagram) to any network, and to make the datagram independent of the target, for the IP datagram assigned a full network unique delivery address (called IP address), to achieve IP address recognition and management.       The transport layer provides an end-to-end communication function for the application, similar to the transport layer in OSI/RM. This layer protocol handles the communication problem that the IP layer does not handle, guarantees the reliability of the communication connection, and can automatically adapt to the various changes of the network, the transmission layer has two protocols: TCP Transmission Control Protocol, User Datagram Protocol UDP.       The application layer is located above the transport layer and contains all the high-level protocols to provide the user with the various services required. The main services are remote login (telnet), File transfer (FTP), e-mail (SMTP), Web Service (HTTP), Domain Name System (DNS), and so on.

The meaning and function of TCP/IP protocol analysis