A media proxy receive a first message from a near end of a path of a communications session, and before receiving a corresponding message from a far end, the media proxy is arranged to detect a blocking situation where another device in the path is awaiting the first message before forwarding the corresponding message. The male connector is surface-mounted to the circuit board and has a housing and terminals. Since the gaseous component treatment sheet is a sheet-like member including the base film for holding the particulate remover, the size and the shape can be adjusted easily. The metering plate is also adapted to receive two or more flow meters at the two or more passages, respectively.