METHOD OF SELECTING ROUTING SCENARIO BY TRANSIT NETWORK SELECTION INFORMATION ELEMENTS

PURPOSE: A method for deciding a routing scenario and a recording medium for reading a program by using a computer are provided to divide the call of domestic station from a relayed call by analyzing a receiving number included in a signal message in a B-ISDN(Broadband Integrated Service Digital Network) and to pass through a relay network established by a sending subscriber by using a transit network selection information element in a call establishing message to the relayed call. CONSTITUTION: A public switching board receiving a call establishing message including a transit network selection information or sending switching board of a sending subscriber network compares two public network service information for recognizing the state of network structure. Therefore, the public switching board selects the public network service network for routing a call in the own switching board. Then, the demanding message of call establishment is transferred the next switching board for including the information about transit network needed for establishing the call by using the transit network selected by the sending subscriber through translating the number in the next switching board. Therefore, the sending subscriber in a B-ISDN environment including plural services selects the transit network to pass through according to the fare, supplied service, and quality of service. Also, the public network establishes the call passing through the transit network selected by the sending subscriber.