How the TCP/IP protocol implements the Network Model

Layer functions TCP/IP protocol family in OSI
Application Layer file transmission, email, file service, virtual terminal TFTP, HTTP, SNMP, FTP, SMTP, DNS, Telnet
Presentation layer data formatting, code conversion, data encryption, no protocol
There is no agreement for the Session Layer to terminate or establish a contact with another contact

Transport Layer provides end-to-end interfaces TCP and UDP
Select the Route IP, ICMP, RIP, OSPF, BGP, and IGMP for data packets at the network layer.
The data link layer provides the address frame and Error Detection Functions SLIP, CSLIP, PPP, ARP, RARP, and MTU.
The physical layer transmits data ISO2110, IEEE802, and 802.2 to physical media in the form of binary data.

The data link layer includes hardware interfaces and protocols ARP and RARP. These two protocols are used to establish information sent to the physical layer and receive information uploaded from the physical layer;
The protocols at the network layer mainly include IP, ICMP, and IGMP. because they contain IP protocol modules, they are the core of all the opportunities for TCP/IP protocol networks. At the network layer, the IP module completes most of the functions. ICMP, IGMP, and other protocols that support IP addresses help IP addresses complete specific tasks, such as transmitting error control information and control messages between hosts and routers. The network layer is responsible for information transmission between hosts in the network.

The main protocols on the transport layer are TCP and UDP. Just as the network layer controls data transmission between hosts, the transport layer controls the data that will enter the network layer. The two protocols are the two methods for managing the data: TCP is a connection-based protocol. Do you still remember the connection-oriented service and connection-free service concepts we mentioned in the network basics? If you forget it, check it out.) UDP is a management protocol for the connectionless service.

The application layer is at the top of the protocol stack, and its main task is application. The above protocols are also designed for these applications. Specifically, some common protocol functions are as follows:
Telnet: provides remote login terminal simulation) service, as if the older BBS is used for this login.
FTP: provides application-level file transfer services, which are simple and clear: Remote File Access and other services;
SMTP: The E-mail protocol used every day.
TFTP: provides a small and simple File Transfer Service. In fact, from a certain perspective, it is a replacement for FTP when the file is very small and only needs to be transferred ).
SNTP: Simple Network Management Protocol. Let alone the meaning of the name.
DNS: The domain name resolution service, that is, how to map domain names to city IP addresses.
HTTP: Are you familiar with this protocol? This is a hypertext transfer protocol. The reason why you can see images, animations, audios, and so on the internet is that this Protocol is working!

In addition, we also need to pay attention to a problem that we have previously mentioned. The protocol works when the data of "peer-to-peer entity" is interacted. If you forget it, remember it.

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