Method of producing a polyester resin container, such as a PET bottle, from a preform includes a step whereby the preform is heated to a temperature above a glass-transition temperature and a drawing step which is performed in a cavity. While the pressure of the interior of the vacuum chamber is being controlled, high-frequency power is supplied to one end of a first conductor which is opened at another end, and which is configured as a vortex. Client devices establish synchronization sessions with either a proxy synchronization server or a master synchronization server, depending on which server provides the \u201cbest\u201d available connection to that client device.