1. reserved port number: according to iana (internet assigned numbers authority), port numbers from 0 to 1023 are reserved port numbers, which are used for common services and protocols (such as port 80 of HTTP).

2. Dynamic allocation of port numbers: Some protocols (such as TCP and UDP) specify the range of dynamic allocation of port numbers, usually 1024 to 49 15 1. These port numbers can be used for temporary connections and protocols.

3. Custom port number: For self-developed application-specific protocols, you can choose a port number greater than 49 15 1 to avoid conflicts with commonly used port numbers.

Please note that the following principles should be followed when selecting port numbers:

-Avoid using already occupied port numbers to avoid conflicts.

-You can check the list of IANA services to avoid selecting port numbers similar to existing services, so as to avoid confusion and misunderstanding.

-Consider security and avoid using port numbers that are easy to be scanned and attacked.

Generally speaking, when selecting the server port number, you can choose a port number greater than 49 15 1, and follow the relevant port number selection principles and security requirements.