Method for detecting TCP packet losses and expediting packet retransmission
AssigneeAppEx NETWORKS HOLDING LIMITED
InventorsYongdong Wang, Hao Zhuang
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Abstract
A computer-implemented method for detecting TCP packet losses and expediting packet retransmission is disclosed. The method includes assigning to each packet transmitted or retransmitted a sequential order number; determining from an ACK packet or SACK segment thereof the sequential order number of a received packet; recording the determined sequential order number as a highest order number in case the determined sequential order number is greater than a current received order number, and retransmitting all unacknowledged packets having sequential order numbers less than the highest received order number.
Claims5
A computer-implemented method for detecting TCP packet losses and expediting the retransmission thereof comprising:
- assigning to each packet transmitted or retransmitted a sequential order number;
- determining from an ACK packet or SACK segment thereof the sequential order number of a received packet;
- recording the determined sequential order number as a highest-recv-order number in case the determined sequential order number is greater than the current highest-recv-order number;
- retransmitting unacknowledged packets having sequential order numbers less than the highest-recv-order number;
- and
- transmitting a probe packet in case no packets are transmitted or retransmitted for a pre-determined period of time and there is at least one unacknowledged packet, the probe packet having at least one byte from the packet having the highest sequential order number.
A computer-implemented method of determining a difference between sequence numbers in SACK segments and sequence numbers they represent comprising the steps of:
- sending at least one probe packet following transmission of the first data packet, the probe packet being a portion of a selected untransmitted packet and having a length not equal to the length of any packet with a sequence number less than that of the selected untransmitted packet;
- and
- determining the difference between a sequence number of a received SACK segment and a corresponding sequence number of the probe packet following receipt of an ACK packet having a SACK segment equal in length to the length of the probe packet.
Dependencies are inferred from the claim text.