What do TCP ports and UDP ports mean?

1, TCP port refers to the port that provides services for TCP protocol communication. In TCP transmission control protocol, the establishment of end-to-end connection depends on the interaction between IP address and TCP port number. UDP port refers to the port that provides services for UDP protocol communication. UDP is the abbreviation of User Datagram Protocol, whose Chinese name is User Datagram Protocol, which is a connectionless transport layer protocol in OSI (Open Systems Interconnection) reference model.

Servers are usually identified by well-known port numbers. Any TCP/IP implementation provides services with well-known port numbers between 1 and 1023. These well-known port numbers are managed by the Internet Assigned Numbers Authority (IANA).

The port addresses in the TCP and UDP segment structures of extended data are 16 bits, and can have port numbers in the range of 0-65535. For these 65536 port numbers, there are the following usage rules:

(1) Port numbers less than 256 are defined as public ports, and servers are generally identified by public port numbers. Services provided by any TCP/IP implementation use port numbers between 1- 1023, which are managed by ICANN;

(2) The client only needs to ensure that the port number is unique on this machine. Customer port number is also called temporary port number because of its short existence time;

(3) Most TCP/IP implementations allocate temporary port numbers between 1024-5000. Port numbers greater than 5000 are reserved for other servers.

References:

Baidu encyclopedia -UDP

References:

Baidu encyclopedia -TCP port