Patent ID: 9379852
Filing Date: 2016-06-28
CPC Classification: H04L

Claim Text:
1. A packet recovery method upon loss of part of a plurality of packets transmitted from a first node to a second node through a network in order of sequence numbers assigned to each of said plurality of packets, wherein: a plurality of a series of sequence numbers are available for packet communication between said first node and said second node through a plurality of different paths in said network, and said plurality of different paths including a first path and a second path; said first node assigns numbers determined based on a first series of sequence numbers from among said plurality of a series of sequence numbers when said plurality of packets are transmitted to said second node; said first node transmits said plurality of packets whose numbers are assigned based on said first series of sequence numbers to said second node through said first path; said second node, upon detection of a loss of a packet from among said plurality of packets transmitted from said first node, transmits an acknowledgement message to said first node through said first path, said acknowledgement message including a Sack (Selective Acknowledgement) block which has information on a sequence number of a packet from among said plurality of packets, whose reception has been confirmed or whose loss has been detected and information on a lost packet from among said plurality of packets; said first node, upon receipt of said acknowledgement message from said second node and when a retransmission packet which is a packet from among said plurality of packets is transmitted to said second node, assigns to said retransmission packet a sequence number which is a number pertinent to a first-time transmission packet subsequent to a final sent packet with second series of sequence numbers being different from said first series of sequence numbers when said retransmission packet is transmitted to said second node, each number of said second series of sequence numbers being different from each number of said first series of sequence numbers; said first node includes information on a sequence number of a packet from among said plurality of packets, whose reception has been confirmed or whose loss has been detected in an acknowledgement-to-acknowledgement message for notifying that said acknowledgement message has been received and transmits said acknowledgement-to-acknowledgement message attached to said retransmission packet, to said second node through said second path, such that said second node does not resend said acknowledgment message to said first node upon receiving said acknowledgement-to-acknowledgement message; and said second node, upon receipt of said acknowledgement-to-acknowledgement message, does not request a retransmission for a packet from among said plurality of packets, which has been assigned a sequence number previous to a notified sequence number.