An upright-type vacuum cleaner includes a cleaner body, a suction brush, cyclone dust collecting means, and filtering means. The first sub-population is one of a plurality of sub-populations that form a population of candidate solutions to an optimization problem. The resistors have resistance depending on the length of the signal lines connected thereto. The solution allows a connection to be established between users of a real-time media communication service for subscribers of separate administrative subsystems so that operators of each subsystem may possess full control of their own network elements, and the internal connection establishment procedures need minimal alterations for the functionality.