1. Port number
The so-called port is like a house number. The client can find the corresponding server through the IP address , but the server has many ports. Each application corresponds to a port number. Through the port number similar to the house number, the client The client can actually access the server. In order to distinguish the ports, each port is numbered, which is the port number. Generally 4 bytes, 16 bits
2. TCP/IP protocol
TCP/IP (Transmission Control Protocol/Internet Protocol, Transmission Control Protocol/Internet Protocol) refers to a protocol cluster that can realize information transmission between multiple different networks. The TCP/IP protocol not only refers to the two protocols of TCP and IP , but refers to a protocol cluster composed of FTP , SMTP , TCP, UDP , IP and other protocols, just because the TCP protocol and the IP protocol in the TCP/IP protocol The most representative, so it is called the TCP/IP protocol.
3、SIP
It is a text-based application layer control protocol for creating, modifying and releasing sessions of one or more participants
4、html
The full name of HTML is Hypertext Markup Language , which is a markup language . It includes a series of tags . Through these tags, the document format on the network can be unified, and the scattered Internet resources can be connected into a logical whole. HTML text is descriptive text composed of HTML commands , which can explain text , graphics , animations , sounds , tables , links , etc.
5、http
Hypertext Transfer Protocol (Hyper Text Transfer Protocol, HTTP) is a simple request-response protocol, which usually runs on top of TCP . It specifies what kind of messages the client may send to the server and what kind of responses it may get. The headers of the request and response messages are given in ASCII
6、FTP
file transfer protocol
7、SMTP
SMTP is a protocol that provides reliable and efficient email transmission . SMTP is a mail service built on the FTP file transfer service . It is mainly used for the transfer of mail information between systems and provides notifications about incoming mail. SMTP is independent of a specific transmission subsystem, and only requires reliable and orderly data flow channel support. One of the important features of SMTP is that it can transmit mail across the network, that is, "SMTP mail relay". Using SMTP, mail transmission between processing processes on the same network can be realized, and mail transmission between a processing process and other networks can also be realized through repeaters or gateways. on port 25
8、EXP
UDP - based Data Transfer Protocol (UDP-based Data Transfer Protocol, referred to as UDT) is an Internet data transfer protocol. The main purpose of UDT is to support massive data transmission on high-speed WAN , while the standard data transmission protocol TCP on the Internet has poor performance on high-bandwidth long-distance networks. As the name suggests, UDT is built on top of UDP and introduces new congestion control and data reliability control mechanisms. UDT is a connection-oriented bidirectional application layer protocol. It supports both reliable stream delivery and partially reliable datagram delivery.