Patent ID: 6961327

Claim:
A TCP local retransmission scheme, used in an unreliable network, is comprised of: A. when an access point of an unreliable link receives a new TCP data packet from an Internet TCP source, said access point inserting into said data packet, an LAC-PDU head with a timestamp of a first local sequence number; said data packet encapsulated as an LAC-PDU packet comprising “LAC-PDU head+IP head+TCP head+Data”; B. delivering said data packet to a current terminal; said current terminal producing an acknowledgement packet (ACK 1 ) comprising an acknowledgement number (AN) when said current terminal successfully receives a TCP data packet; said current terminal also inserting to said LAC-PDU head, a time-stamp of a second local sequence number such that said acknowledgement packet is encapsulated as an LAC-PDU acknowledgement packet and is delivered back to said access point of an unreliable link; C. at said access point of an unreliable link, detecting whether there is data packet loss based on said time-stamp of a first local sequence number, stored in said access point, said acknowledgment number (AN) and said time-stamp of a second local sequence number, wherein both are determined from said acknowledgement packet; and D. if a lost data packet is detected, updating and retransmitting said time-stamp of a first local sequence number in LAC-PDU head, and when congestion loss of the data packet which corresponds to said acknowledgement number (AN) of acknowledgement packet (ACK 1 ) is impossible, said acknowledgement packet (ACK 1 ) along with a marked explicit retransmission feedback (ERN) field is delivered to said Internet TCP source.