A gas-fired humidifier comprising a heat exchanger with a plurality of generally upwardly extending tubes. In one advantageous embodiment of the present invention, the call processing system: determines that a call composed of a stream of continuous media communication packets and associated with the UCD requires a specified alternative processing and causes the continuous media communication data packets associated with the call to be processed in accordance with the specified alternative processing. Legs of the detached leg frame are further assembled with a footrest for storage purpose. It can also be composed of a combination of two or more partial vectors. A connection position between the push-in fixing portion and the connection portion is bent and a part of the contact-fitting portion is bent in such a fashion that the positions of the fixed contacts and the positions of the terminal portions are deviated with respect to an implanting direction of the fixed contact plates.