The phone number was hardly the "first unique identifier in a network" and switchboards worked just fine before phone numbers; phone numbers were first added in the 1890s because of the Stronger switch.
The first UUIDs in networks were probably titles (nobility or job titles in a byzantine empire like China, Russia or, less, the Ottoman Empire). "Chief Assistant to the Assistant Chief of Shipbuilding" is a unique node identifier (doesn't identify a person, but then again phone numbers are reused too).
The first UUIDs in networks were probably titles (nobility or job titles in a byzantine empire like China, Russia or, less, the Ottoman Empire). "Chief Assistant to the Assistant Chief of Shipbuilding" is a unique node identifier (doesn't identify a person, but then again phone numbers are reused too).