FAILURE DETECTION DEVICE, METHOD AND PROGRAM

PROBLEM TO BE SOLVED: To provide a technique which identifies a location on a communication network degrading voice quality of voice communication.SOLUTION: A failure detection device utilized in a communication network performing voice communication between a first user terminal and a second user terminal comprises: acquisition means for retrieving each of call control packets and voice packets flowing in the communication network from a plurality of locations in the communication network; management means for managing, for each call, call information including voice quality information of the direction from the first user terminal to the second user terminal and the voice quality information of the direction from the second user terminal to the first user terminal at each of the locations on the basis of the call control packets and the voice packets retrieved from each of the locations; and identification means for identifying a failure location degrading the voice quality of the voice communication, according to the call information managed by the management means.