Patent Number: 
Section: claims

1. An error detection device comprising:a control unit configured to:identify a link pair having a first link connecting a first communication device to a third communication device and a second link connecting a second communication device to the third communication device,identify (N+1) number of first inspection devices that connect to the first communication device through third links, and (N+1) number of second inspection devices that connect to the second communication device through fourth links, the number N being the number of links where communication errors simultaneously occur,determine (N+1) number of inspection flows between (N+1) number of inspection device pairs by relating on a one-to-one basis the (N+1) number of first inspection devices to the (N+1) number of second inspection devices,generate inspection coverage information that includes the determined inspection flows, andanalyze each of the inspection flows that is transmitted by one inspection device of each of the inspection device pairs and received by the other one inspection device of each of the inspection device pairs to determine whether the link pair has an communication error;a storage unit that stores the inspection coverage information; anda communication unit that sends the inspection coverage information from the control unit to the one inspection device of each of the inspection device pairs. 2. The error detection device according to claim 1, wherein the control unit determines the inspection device pairs not to overlap with each other. 3. The error detection device according to claim 1,further comprising route information that designates a route by designating an inspection device pair and links connecting the designated inspection device pair;wherein the control unit determines the inspection flows based on the route information. 4. The error detection device according to claim 1,further comprising device log information that includes numbers of times by which the inspection devices are selected as the inspection device pairs;wherein the control unit refers to the device log information to select inspection devices with low numbers of times selected or inspection devices with probability ratios that are inversely proportional to past numbers of times extracted so as to identify the inspection device pairs. 5. The error detection device according to claim 1,further comprising inspection device status information that manages statuses of the inspection devices and device link information that manages correspondence relationships between the inspection device pairs and links connecting each inspection device of the inspection device pairs;wherein when the inspection device status information indicates that a fault has occurred in an inspection device, the control unit refers to the device link information, removes the inspection device in which the fault has occurred, and re-determines the inspection flows that detects the communication error of the link pair. 6. A communication error detection system comprising:a plurality of communication devices;a plurality of inspection devices including first inspection devices and second inspection devices;an error detection device comprising a control unit configured to:identify a link pair having a first link connecting a first communication device to a third communication device and a second link connecting a second communication device to the third communication device, the first to third communication devices selected among the plurality of communication devices,identify (N+1) number of the first inspection devices that connect to the first communication device through third links, and (N+1) number of the second inspection devices that connect to the second communication device through fourth links, the number N being the number of links where communication errors simultaneously occur,determine (N+1) number of inspection flows between (N+1) number of inspection device pairs by relating on a one-to-one basis the (N+1) number of first inspection devices to the (N+1) number of second inspection devices,generate inspection coverage information that includes the determined inspection flows, andanalyze each of the inspection flows that is transmitted by one inspection device of each of the inspection device pairs and received by the other one inspection device of each of the inspection device pairs to determine whether the link pair has an communication error;a storage unit that stores the inspection coverage information; anda communication unit that sends the inspection coverage information to one device of each of the inspection device pairs. 7. The communication error detection system according to claim 6, wherein the control unit identifies the inspection device pairs that do not overlap with each other from the plurality of inspection devices. 8. The communication error detection system according to claim 6, wherein the error detection device comprises route information that designates a route by designating an inspection device pair and links connecting the designated inspection device pair, and the control unit designates the inspection flows based on the route information. 9. The communication error detection system according to claim 6, whereinthe error detection device comprises device log information that includes numbers of times by which the inspection devices are selected as the inspection device pairs, andthe control unit refers to the device log information to select inspection devices with low numbers of times selected or inspection devices with probability ratios that are inversely proportional to past numbers of times extracted so as to identify the pairs. 10. The communication error detection system according to claim 6, whereinthe error detection device comprises inspection device status information that manages statuses of the inspection devices and device link information that manages correspondence relationships between the inspection device pairs and the link pairs and links connecting each inspection device of the inspection device pairs, andwhen the inspection device status information indicates that a fault has occurred in an inspection device, the control unit refers to the device link information, removes the inspection device in which the fault has occurred, and re-determines the inspection flows that detects the communication error of the link pair. 11. A communication error detection method comprising:identifying, by a error detection device, a link pair having a first link connecting a first communication device to a third communication device and a second link connecting a second communication device to the third communication device;identifying, by the error detection device, (N+1) number of first inspection devices that connect to the first communication device through third links, and (N+1) number of second inspection devices that connect to the second communication device through fourth links, the number N being the number of links where communication errors simultaneously occur;determining, by the error detection device, (N+1) number of inspection flows between (N+1) number of inspection device pairs by relating on a one-to-one basis the (N+1) number of first inspection devices to the (N+1) number of second inspection devices;generating, by the error detection device, inspection coverage information that includes the determined inspection flows; andanalyzing, by the error detection device, each of the inspection flows that is transmitted by one inspection device of each of the inspection device pairs and received by the other one inspection device of each of the inspection device pairs to determine whether the link pair has an communication error. 12. The communication error detection method according to claim 11, wherein the determining includes selecting the inspection device pairs not to overlap with each other. 13. The communication error detection method according to claim 11, wherein the determining includes determining the inspection flows based on route information, the route information designating a route by designating an inspection device pair and links connecting the designated inspection device pair. 14. The communication error detection method according to claim 11, wherein the determining includes selecting the inspection device pairs from inspection devices with low numbers of times selected or inspection devices with probability ratios that are inversely proportional to past numbers of times extracted by referring to device log information that includes numbers of times by which the inspection devices are selected as the inspection device pairs. 15. The communication error detection method according to claim 11, wherein the determining includes removing an inspection device in which a fault has occurred and re-determining the inspection flows by referring to device link information, the device link information managing correspondence relationships between the inspection device pairs and the link pairs, when inspection device status information indicates that the fault has occurred in the inspection device, the inspection device status information managing the statuses of the inspection devices. 16. A machine-readable, non-transitory medium storing a program that causes a computer to perform a method, the method comprising:identifying a link pair having a first link connecting a first communication device to a third communication device and a second link connecting a second communication device to the third communication device;identifying (N+1) number of first inspection devices that connect to the first communication device through third links, and (N+1) number of second inspection devices that connect to the second communication device through fourth links, the number N being the number of links where communication errors simultaneously occur;determining (N+1) number of inspection flows between (N+1) number of inspection device pairs by relating on a one-to-one basis the (N+1) number of first inspection devices to the (N+1) number of second inspection devices;generating inspection coverage information that includes the determined inspection flows; andanalyzing each of the inspection flows that is transmitted by one inspection device of each of the inspection device pairs and received by the other one inspection device of each of the inspection device pairs to determine whether the link pair has an communication error. 17. The medium according to claim 16, wherein the determining includes selecting the inspection device pairs not to overlap with each other. 18. The medium according to 16, wherein the determining includes determining the inspection flows based on route information, the route information designating a route by designating an inspection device pair and links connecting the designated inspection device pair. 19. The medium according to 16, wherein the determining includes selecting the inspection device pairs from inspection devices with low numbers of times selected or inspection devices with probability ratios that are inversely proportional to past numbers of times extracted by referring to device log information that includes numbers of times by which the inspection devices are selected as the inspection device pairs. 20. The medium according to claim 16, wherein the determining includes removing an inspection device in which a fault has occurred and re-determining the inspection flows by referring to device link information, the device link information managing correspondence relationships between the inspection device pairs and the link pairs, when inspection device status information indicates that the fault has occurred in the inspection device, the inspection device status information managing the statuses of the inspection devices.