Graham Bell invented it. At first his invention was used for sending and recieving voice signals. Over time, more and more was attached to these lines: first fax signals, then frequency modulated bytes.
Using standard evolution theory there is no need to ask who invented it. The phone system realized its limits and evolved a central DNS system and an HTML language for browsers to interpret, much the way the fish being chased up the beach decided it’s high time to develope feet.