A receiving device comprising: a packet reception unit configured to receive a packet train including a predetermined number of packets with packet sizes incremented by a predetermined increment and transmitted in such a manner that the packets are transmitted at regular intervals, and configured to calculate queuing delay of the packets in the packet train; an available bandwidth calculation unit configured to calculate an estimated value of the available bandwidth based on a macroscopic change point of an increase-decrease rate of the queuing delays, the receiving device being characterized by that said available bandwidth calculation unit includes: a generation unit configured to generate a formulae representing polygonal lines representing the queuing delays in a state free of noise affecting the queuing delays; a square error calculation unit configured to calculate square errors between the queuing delay calculated by the packet reception unit and the formulae representing the polygonal lines generated by the generation unit; and a smallest square error polygonal line determination unit configured to identify the polygonal line with a smallest one of the square errors calculated by the square error calculation unit; and an available bandwidth estimated value calculation unit configured to calculate the estimated value of the available bandwidth on the base of the polygonal line identified by the smallest square error polygonal line determination unit. a packet reception unit configured to receive a packet train including a predetermined number of packets with packet sizes incremented by a predetermined increment and transmitted in such a manner that the packets are transmitted at regular intervals, and configured to calculate queuing delay of the packets in the packet train; an available bandwidth calculation unit configured to calculate an estimated value of the available bandwidth based on a macroscopic change point of an increase-decrease rate of the queuing delays, the receiving device being characterized by that said available bandwidth calculation unit includes: a generation unit configured to generate a formulae representing polygonal lines representing the queuing delays in a state free of noise affecting the queuing delays; a square error calculation unit configured to calculate square errors between the queuing delay calculated by the packet reception unit and the formulae representing the polygonal lines generated by the generation unit; and a smallest square error polygonal line determination unit configured to identify the polygonal line with a smallest one of the square errors calculated by the square error calculation unit; and an available bandwidth estimated value calculation unit configured to calculate the estimated value of the available bandwidth on the base of the polygonal line identified by the smallest square error polygonal line determination unit. a generation unit configured to generate a formulae representing polygonal lines representing the queuing delays in a state free of noise affecting the queuing delays; a square error calculation unit configured to calculate square errors between the queuing delay calculated by the packet reception unit and the formulae representing the polygonal lines generated by the generation unit; and a smallest square error polygonal line determination unit configured to identify the polygonal line with a smallest one of the square errors calculated by the square error calculation unit; and an available bandwidth estimated value calculation unit configured to calculate the estimated value of the available bandwidth on the base of the polygonal line identified by the smallest square error polygonal line determination unit.