Method, system and article for improved TCP performance during packet reordering
First Claim
1. A method for improved transport layer performance following packet reordering in a network, wherein the network comprises a network connection between a sender and a receiver and wherein the network connection operates in a congestion state, said method comprising the steps of:
- receiving a predetermined threshold number of first acknowledgements requesting a data packet be transmitted over the network connection operating in a first congestion state;
in response to receiving the predetermined threshold number of first acknowledgements, transmitting the requested data packet over the network connection from the sender to the receiver;
receiving a second acknowledgement indicating that the requested data packet has been received by the receiver;
calculating the difference between the time that the second acknowledgement was received and the time that the requested data packet was transmitted;
setting the congestion state of the network connection to the first congestion state, if the difference is less than a threshold round-trip-time, wherein the threshold round-trip-time is a minimum round-trip-time for a data packet over the network connection between the sender and the receiver; and
setting the congestion state of the network connection to a second congestion state, if the difference is greater than the threshold round-trip-time, wherein the second congestion state is less than the first congestion state.
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Accused Products
Abstract
TCP congestion avoidance is implemented upon retransmission of a packet and is reverted back to the original congestion state upon receipt of an early acknowledgement (ACK), indicating reordering of packets, thereby eliminating a needless restriction on TCP bandwidth. Upon receiving an ACK to a retransmitted packet, it is determined if the ACK resulted from receipt of the original reordered packet or the retransmitted packet, based on the arrival time of the ACK at the sender. If the round-trip-time (RTT) for the retransmitted packet is much lower than the average or current calculated RTT for the network link between sender and receiver, then the retransmission occurred as a result of a reordering event, and the congestion window is restored back to its value prior to the retransmission, thereby permitting the network link to continue operating at its original increased throughput.
102 Citations
30 Claims
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1. A method for improved transport layer performance following packet reordering in a network, wherein the network comprises a network connection between a sender and a receiver and wherein the network connection operates in a congestion state, said method comprising the steps of:
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receiving a predetermined threshold number of first acknowledgements requesting a data packet be transmitted over the network connection operating in a first congestion state;
in response to receiving the predetermined threshold number of first acknowledgements, transmitting the requested data packet over the network connection from the sender to the receiver;
receiving a second acknowledgement indicating that the requested data packet has been received by the receiver;
calculating the difference between the time that the second acknowledgement was received and the time that the requested data packet was transmitted;
setting the congestion state of the network connection to the first congestion state, if the difference is less than a threshold round-trip-time, wherein the threshold round-trip-time is a minimum round-trip-time for a data packet over the network connection between the sender and the receiver; and
setting the congestion state of the network connection to a second congestion state, if the difference is greater than the threshold round-trip-time, wherein the second congestion state is less than the first congestion state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A data processing system providing improved transport layer performance following packet reordering in a network, said system comprising:
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wherein the network comprises a network connection between a sender and a receiver and wherein the network connection, means for receiving from a receiver a predetermined threshold number of first acknowledgements requesting a data packet be transmitted, while operating a network connection between the data processing system and the receiver in a first congestion state;
means for, in response to receiving the predetermined threshold number of first acknowledgements, transmitting the requested data packet to the receiver;
means for receiving a second acknowledgement indicating that the requested data packet has been received by the receiver;
means for calculating the difference between the time that the second acknowledgement was received and the time that the requested data packet was transmitted;
means for operating the network connection in the first congestion state, if the difference is less than a threshold round-trip-time, wherein the threshold round-trip-time is a minimum round-trip-time for a data packet over the network connection between the sender and the receiver; and
means for operating the network connection in a second congestion state, if the difference is greater than the threshold round-trip-time, wherein the second congestion state is less than the first congestion state. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An article of manufacture for improved transport layer performance following packet reordering in a network, wherein the network comprises a network connection between a sender and a receiver and wherein the network connection operates in a congestion state, comprising machine-readable medium including program logic embedded therein that causes control circuitry in a data processing system to perform the steps of:
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receiving a predetermined threshold number of first acknowledgements requesting a data packet be transmitted over the network connection operating in a first congestion state;
in response to receiving the predetermined threshold number of first acknowledgements, transmitting the requested data packet over the network connection from the sender to the receiver;
receiving a second acknowledgement indicating that the requested data packet has been received by the receiver;
calculating the difference between the time that the second acknowledgement was received and the time that the requested data packet was transmitted;
setting the congestion state of the network connection to the first congestion state, if the difference is less than a threshold round-trip-time, wherein the threshold round-trip-time is a minimum round-trip-time for a data packet over the network connection between the sender and the receiver; and
setting the congestion state of the network connection to a second congestion state, if the difference is greater than the threshold round-trip-time, wherein the second congestion state is less than the first congestion state. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification