Systems and methods of using packet boundaries for reduction in timeout prevention

Patent metadata

Field	Value
Publication number	US-9496991-B2
Application number	US-201213544533-A
Country	US
Kind code	B2
Filing date	Jul 9, 2012
Priority date	Oct 30, 2002
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Systems and methods for utilizing transaction boundary detection methods in queuing and retransmission decisions relating to network traffic are described. By detecting transaction boundaries and sizes, a client, server, or intermediary device may prioritize based on transaction sizes in queuing decisions, giving precedence to smaller transactions which may represent interactive and/or latency-sensitive traffic. Further, after detecting a transaction boundary, a device may retransmit one or more additional packets prompting acknowledgements, in order to ensure timely notification if the last packet of the transaction has been dropped. Systems and methods for potentially improving network latency, including retransmitting a dropped packet twice or more in order to avoid incurring additional delays due to a retransmitted packet being lost are also described.

First claim

We claim:

1. A method for reducing transmission timeouts, comprising:
(a) receiving, by a device via a connection between a sender and a receiver, a first packet transmitted from the sender to the receiver, the first packet having a first retransmission timeout time;
(b) transmitting, by the device, the first packet to the receiver;
(c) determining, by the device, that the connection has a loss rate exceeding a threshold;
(d) selecting, by the device, responsive to determining that the loss rate exceeds the threshold, a number of additional packets to transmit based on the loss rate;
(e) generating, by the device, a plurality of additional packets equaling the selected number of additional packets, responsive to determining that the loss rate exceeds the threshold and responsive to selecting the number of additional packets to transmit based on the loss rate; and
(f) transmitting, by the device, the plurality of additional packets to the receiver prior to the first retransmission timeout time.

2. The method of claim 1 , further comprising:
(g) receiving, by the device from the receiver, an acknowledgement for the plurality of additional packets prior to receiving an acknowledgement for the first packet and prior to the first retransmission timeout time, the acknowledgement indicating that one or more packets were not received; and
(h) retransmitting, by the device, the one or more packets prior to the first retransmission timeout time, responsive to receipt of the acknowledgement.

3. The method of claim 2 , wherein (h) further comprises transmitting, by the device, an indication to the sender indicating the one or more packets were not received and should be retransmitted.

4. The method of claim 1 , wherein transmitting the plurality of additional packets comprises transmitting the plurality of additional packets after a period of time.

5. The method of claim 1 , wherein transmitting the plurality of additional packets comprises transmitting the plurality of additional packets immediately following the first packet.

6. The method of claim 1 , wherein generating plurality of additional packets comprises determining that the first packet is a last packet of a transaction between the sender and the receiver; and generating the plurality of additional packets responsive to the determination.

7. The method of claim 1 , wherein the plurality of additional packets comprises a duplicate of the first packet.

8. The method of claim 1 , wherein the plurality of additional packets comprises a portion of the first packet.

9. The method of claim 1 , wherein the plurality of additional packets comprises a plurality of corresponding packets generated according to a forward error correction technique.

10. The method of claim 1 , wherein (c) further comprises determining that the loss rate is below a second threshold; and
wherein (d) further comprises selecting the number of additional packets from a plurality of a numbers of additional packets, each number associated with one of a corresponding plurality of loss rate ranges.

11. A system for reducing transmission timeouts, comprising:
a device in communication with a sender and a receiver comprising:
a packet processor configured for receiving a first packet from the sender and transmitting the first packet to the receiver, the first packet having a first retransmission timeout time; and
a flow controller configured for:
determining that a connection has a loss rate exceeding a threshold;
selecting, responsive to determining that the loss rate exceeds the threshold, a number of additional packets to transmit based on the loss rate;
generating a plurality of additional packets equaling the selected number of additional packets, responsive to determining that the loss rate exceeds the threshold and responsive to selecting the number of additional packets to transmit based on the loss rate; and
transmitting the plurality of additional packets to the receiver prior to the first retransmission timeout time.

12. The system of claim 11 , wherein the packet processor is further configured for receiving, from the receiver, an acknowledgement for the plurality of additional packets prior to receiving an acknowledgement for the first packet and prior to the first retransmission timeout time, the acknowledgement indicating that one or more packets were not received; and retransmitting, by the device, the one or more packets prior to the first retransmission timeout time, responsive to receipt of the acknowledgement.

13. The system of claim 12 , wherein the flow controller is further configured for transmitting an indication to the sender indicating the one or more packets were not received and should be retransmitted.

14. The system of claim 11 , wherein the flow controller is further configured for transmitting the plurality of packets after a period of time.

15. The system of claim 11 , wherein the flow controller is further configured for transmitting the plurality of additional packets immediately following the first packet.

16. The system of claim 11 , wherein the flow controller is further configured for determining that the first packet is a last packet of a transaction between the sender and the receiver; and generating the plurality of additional packets responsive to the determination.

17. The system of claim 11 , wherein the pluralty of additional packets comprises a duplicate of the first packet.

18. The system of claim 11 , wherein the plurality of additional packets comprises a portion of the first packet.

19. The system of claim 11 , wherein the plurality of additional packets comprises a packet generated according to a forward error correction technique.

Assignees

• Plamondon Robert
• Ovsiannikov Michael
• Samuels Allen R
• Citrix Systems Inc

Inventors

• Plamondon Robert
• Ovsiannikov Michael
• Samuels Allen R

Classifications

• H04L69/166

  IP fragmentation; TCP segmentation · CPC title

• H04L1/189

  Transmission or retransmission of more than one copy of a message · CPC title

• H04L67/2876

  Pairs of inter-processing entities at each side of the network, e.g. split proxies · CPC title

• H04L43/0829

  Packet loss · CPC title

• H04L47/40

  using split connections · CPC title