An obstruction determination program for causing a computer to execute an obstruction determination process, the obstruction determination process including determining the presence or absence of an abnormality for each of a plurality of transfer paths on which a plurality of transfer devices (16S1-16S5) are provided for performing transfer of data between a server device and a plurality of respective client devices(14C1-14C4), with a plurality of the individual transfer devices (16S1-16S5) positioned on each of the transfer paths, the obstruction determination process comprising: (a) based on connection data received from each of the plurality of transfer devices (16S1-16S5), which indicates which of each of the transfer devices (16S1-16S5) is connected to which device among the server device, the plurality of client devices (14C1-14C4) or the plurality of transfer devices (16S1-16S5), determining whether or not the connection data has been received from a plurality of transfer devices (16S1-16S5) connected to a non-transmitting transfer device that is a transfer device that is not transmitting the connection data; (b) in cases in which it is determined at (a) that the connection data has been received from a plurality of the transfer devices (16S1-16S5) connected to the non-transmitting transfer device, based on transfer path identification data that has been received from each of the plurality of transfer devices (16S1-16S5) connected to the non-transmitting transfer device and that identifies the transfer path on which the transfer device is positioned, identifying a non-transmitting transfer device transfer path that is a transfer path on which the non-transmitting transfer device is positioned; and (c) taking each of the plurality of transfer paths as an identified transfer path, and, based on transfer volume data that is received from a plurality of transfer devices (16S1-16S5) positioned on the identified transfer path and that is transfer volume data of data transferred by each of the transfer devices (16S1-16S5), determining for each of the identified transfer paths whether or not an obstruction has occurred on the identified transfer path, and in cases in which the identified transfer path is the non-transmitting transfer device transfer path identified at (b), employing the transfer volume data that has been received from another transfer device positioned on the non-transmitting transfer device transfer path as the transfer volume data of the non-transmitting transfer device to determine whether or not an obstruction has occurred on the identified transfer path. (a) based on connection data received from each of the plurality of transfer devices (16S1-16S5), which indicates which of each of the transfer devices (16S1-16S5) is connected to which device among the server device, the plurality of client devices (14C1-14C4) or the plurality of transfer devices (16S1-16S5), determining whether or not the connection data has been received from a plurality of transfer devices (16S1-16S5) connected to a non-transmitting transfer device that is a transfer device that is not transmitting the connection data; (b) in cases in which it is determined at (a) that the connection data has been received from a plurality of the transfer devices (16S1-16S5) connected to the non-transmitting transfer device, based on transfer path identification data that has been received from each of the plurality of transfer devices (16S1-16S5) connected to the non-transmitting transfer device and that identifies the transfer path on which the transfer device is positioned, identifying a non-transmitting transfer device transfer path that is a transfer path on which the non-transmitting transfer device is positioned; and (c) taking each of the plurality of transfer paths as an identified transfer path, and, based on transfer volume data that is received from a plurality of transfer devices (16S1-16S5) positioned on the identified transfer path and that is transfer volume data of data transferred by each of the transfer devices (16S1-16S5), determining for each of the identified transfer paths whether or not an obstruction has occurred on the identified transfer path, and in cases in which the identified transfer path is the non-transmitting transfer device transfer path identified at (b), employing the transfer volume data that has been received from another transfer device positioned on the non-transmitting transfer device transfer path as the transfer volume data of the non-transmitting transfer device to determine whether or not an obstruction has occurred on the identified transfer path.