A common approach is for the server to accept messages at a well-known port.
widely or fully known; "a well-known politician"; "well-known facts"; "a politician who is well known"; "these facts are well known
A well-known person or thing is known about by a lot of people and is therefore famous or familiar. If someone is well-known for a particular activity, a lot of people know about them because of their involvement with that activity. He surrounds himself with attractive, intelligent, or well-known people Hubbard was well known for his work in the field of drug rehabilitation
A well-known fact is a fact that is known by people in general. It is well known that bamboo shoots are a panda's staple diet. known by a lot of people it is well-known (that)