There is no worldwide convention. Go ahead and run your services on whatever ports. That's what I do.

No convention at all, just FTP defaulting to 21 and SSH to 22 and websites to 80 randomly.

There is no Internet Police that will give a fine for using the 'wrong' ports.

(In fact, not running SSH on port 22 is an industry best practice in 2024, sadly.)

You are thinking of a law, not a convention.

A convention is a common language. It is something you have the right to break when needed / suitable but which is otherwise nice to follow when interacting with others.

Such conventions allow you to omit the port when typing a URL in a browser for instance. They allow taking nice shortcuts and avoiding verbose / irrelevant technical details.

(now, some conventions are mandated by laws indeed. For instance, if you are setting up electricity somewhere, you'd better use the right colors. One might argue that we ought to call such things rules)

Conventions are defaults. Every browser I have assumes port 80 (or 443) for http (or https) by default for a reason.

Yes there most certainly is a worldwide convention. Please read the article before commenting. Just because you don't happen to follow the convention does not mean it doesn't exist and isn't worldwide.

> There is no worldwide convention.

Yeah, if only there were an authority that we could agree on to assign numbers for internet things like ports.

Some sort of internet assigned number authority…

https://www.iana.org/assignments/service-names-port-numbers/...