Packet restoration method, packet restoration system, and mobile terminal and intermediate device used in the method

摘要

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.

主权项

1. 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 the correspondent node, the method comprising:
a step of causing the intermediate device to decide to perform, with respect to a discarded packet, one of (i) transmit a discard notification message to the mobile terminal based on information that the present communication flow is a communication flow for which transmission of the discard notification message indicating that the packet has been discarded is required and (ii) not transmit a discard notification message to the mobile terminal based on information that the present communication flow is a communication flow for which transmission of the discard notification message indicating that the packet has been discarded is not required; and a step of causing the mobile terminal to transmit to the correspondent node a retransmission request message for requesting retransmission of the discarded packet based on the discard notification message, wherein the step of transmitting the discard notification message to the mobile terminal includes transmitting by the intermediate device a message to the correspondent node indicating not to perform voluntary retransmission control on the packet even if an ACK message is not received that would otherwise trigger a voluntary retransmission protocol.