The present invention discloses a technique for providing a packet recovery method, and the like, capable of starting packet recovery processing without waiting for a wasteful latency (time-out) at a mobile terminal by giving notice of information on a packet discard in a gateway device in real time, thereby enabling improvement in communication quality and communication efficiency. According to the technique, there is provided a packet recovery method for recovering a packet discarded by an intermediate device positioned on a communication path between a mobile terminal and a correspondent node of the mobile terminal among packets exchanged between the mobile terminal and correspondent node, the method including: a step of causing the intermediate device to transmit a discard notification message to the mobile terminal based on information on a communication flow for which transmission of the discard notification message indicating that the packet has been discarded is required; and a step of causing the mobile terminal to transmit the correspondent node a retransmission request message for requesting retransmission of the discarded packet based the discard notification message.