A method includes integrating information regarding receiving, transmitting and converting capabilities of each device in a network with regard to signal formats, so that a pertinent transmission path can be determined. Such transmission paths can be specified in terms of the order of devices involved in the transmission paths and a signal format between these devices involved. One of the possible transmission paths that match the transmitting device and the transmitted signal format is selected as a pertinent transmission path. The method displays the selected transmission path on a monitor, to assist a user to manually establish a pertinent transmission path.