10 minutes to understand the relationship between TCP/IP protocols and protocols __TCPIP protocol

1. Hardware (physical layer) The bottom layer of TCP/IP is the hardware responsible for data transfer. This hardware is equivalent to a physical layer of equipment such as Ethernet or telephone lines.

2. The network interface layer (data link layer) network interface layer communicates with the data link layer in Ethernet, so it belongs to interface layer. It can also be considered as a NIC driver. Drivers are software that bridges the operating system and hardware.

3. The Internet Layer (network layer) Internet layer uses IP protocol, which is equivalent to the 3rd Layer Network layer in the OSI model. The functionality of the Internet Layer and transport layer in a TCP/IP hierarchy is usually provided by the operating system. All hosts and routers connected to the Internet must implement IP capabilities.

IP Protocol

IP is a protocol that transmits packets across a network to enable the entire Internet to receive data. IP is also a packet switching protocol, but it does not have a retransmission mechanism, so it is unreliable transport protocol.

ICMP

IP packets need to send an exception notification to the sender when an exception occurs that causes the destination address to be unreachable. ICMP is designed for this function.

ARP resolves a protocol for a physical address (MAC address) from the IP address of a packet packet.

4. The primary function of the Transport layer Transport layer is to enable communication between applications.
TCP Protocol

TCP is a connection-oriented transport layer protocol. It can ensure communication between the two ends of the communication between the host to reach. TCP can correctly handle the exception of packet loss, transmission sequence and so on during transmission.

UDP Protocol UDP is a connectionless transport-layer protocol. UDP does not care if the end-to-end data is actually received from the transmitting past. If you need to check whether you receive packet packets on the side, or whether you are connected to the network, you need to implement it in your application.
UDP is commonly used in multimedia fields such as less packet data or multicast, broadcast communication and video communication.

5. Application Layer (hierarchy above the session layer) In the TCP/IP hierarchy, the functionality of the session, presentation, and application tiers in the OSI reference model is centralized in the application.
Most of the schemas for TCP/IP applications belong to the client/server model.

The following are the main applications of the application layer:

WWW

The protocol used to communicate between the browser and the server is the HTTP protocol, and the main format of the data transmitted is the Protocol of HTTP belonging to the OSI application layer in HTML,WWW, and the HTML belongs to the Protocol of the presentation layer.

Email

The protocol used to send an e-mail message is SMTP. Initially, e-mail messages can only be sent in file format. Now that the e-mail format is expanded by the MIME protocol, you can send a wide variety of messages, such as sounds, images, and so on. MIME belongs to the protocol of the presentation layer.

file Transfer (FTP) File transfer refers to transferring files from other computer disks to the local computer, or transferring files on the local disk to other computer disks. The protocol used by this file transfer process is called the FTP protocol.

File transfer in FTP establishes two TCP connections, respectively, to the control connection to use when sending a transmission request and to the data connection that is used when the data is actually transferred.

Remote login (telnet and SSH) is a feature that logs on to a remote computer and enables programs on that computer to run. Remote logins commonly used telnet and ssh two kinds of protocols. (There are some other agreements, of course)

Network Management (SNMP) uses SNMP (Simple network Management Protocol) protocol for network Management in TCP/IP. Hosts, bridges, routers, etc. that are managed using the SNMP protocol are called SNMP agents, and the end of management is called the manager. SNMP is the protocol used by this manager and agent.

At the agent end of SNMP, information such as the information of network interface, the amount of communication data, the amount of abnormal data and the temperature of equipment are preserved. This information can be accessed through the MIB (Management information Base). Therefore, in the TCP/IP network management, SNMP belongs to the application protocol, the MIB belongs to the presentation layer protocol.