A cable connector assembly includes a connector and a cable electrically connected thereto. The connector includes a metal shell, a metal cage enclosing a rear end of the metal shell, and an outer housing enclosing the metal cage therein. The connector has a front end for inserting into a mating connector and a rear end. The diametrical dimension of the front end is smaller than the diametrical dimension of the rear end. The outer housing includes a front portion extending forwardly beyond the metal cage to prevent the cable connector mistakenly inserted into an unintended receptacle connector.