TCP CONGESTION CONTROL FOR HETEROGENEOUS NETWORKS

• US 20110249553A1
• Filed: 04/13/2011
• Published: 10/13/2011
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Cdf K.E. Yuan
• Original Assignee: Cdf K.E. Yuan
• Inventors: Wang, Jingyuan, Han, Yuxing, Wen, Jiangtao
• Granted Patent: US 8,547,839 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04L 47/225 Determination of shaping rate, e.g. using a moving window
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets

Abstract

A congestion control mechanism for TCP communication sessions is described. The congestion control mechanism adjusts the size of the congestion window based on a number, N, of parallel virtual connections. The number N of parallel virtual connections used to determine the congestion window is dynamically adjusted based on an estimation of the network condition.

Claims

1. A method for congestion control of a communication session over a network comprising:

determining an estimation of the network condition;

determining a congestion window for the communication session based on a number of parallel virtual communication sessions that will fully and fairly utilize the bandwidth of the network and a congestion control mechanism of the communication session; and

setting the congestion window for the communication session to the determined congestion window.

2. The method of claim 1, further comprising determining the number of parallel virtual communication sessions based on the determined estimation of the network condition and a congestion control mechanism.

3. The method of claim 2, wherein the number of parallel virtual communication sessions is periodically updated according to:

4. The method of claim 2, wherein the number of parallel virtual communication sessions is periodically updated according to:

5. The method of claim 4, wherein

6. The method of claim 4, wherein

7. The method of claim 3, wherein

8. The method of claim 7, further comprising entering a base_rtt estimation mode to update the value of base_rtt, the base_rtt estimation mode comprising:

setting the number of parallel virtual connections to 1;

determining m RTT samples;

setting min_rtt to the smallest of the m RTT samples; and

updating base_rtt according to;

9. The method of claim 1, further comprising:

selecting the congestion control mechanism for the communication session based on the determined estimation of the network condition.

10. The method of claim 1, wherein determining an estimation of the network condition comprises one or more of:

determining an estimate of network propagation delay between a sender and a receiver of the communication session;

determining an estimate of a number of in-flight packets between the sender and the receiver of the communication session;

determining an estimate of network bandwidth between the sender and the receiver of the communication session; and

determining an estimate of a packet loss rate between the sender and the receiver of the communication session.

11. The method of claim 10, wherein:

the estimate of network propagation delay is determined based on the round trip time (RTT) observed by the sender;

the estimate of the number of in-flight packets is determined based on the RTT and the congestion window.

12. The method of claim 1, wherein the congestion control mechanism is selected from:

TCP-Reno;

TCP-Vegas;

TCP-Fast;

Compound TCP;

TCP Veno;

TCP Westwood;

TCP Cubic; and

TCP BIC.

13. A computing device for controlling congestion of a communication session over a network comprising:

a processing unit for executing instructions; and

a memory unit for storing instructions for execution by the processing unit, the instructions when executed configuring the computing device to provide;

a network condition estimation means for determining an estimation of the network condition;

a congestion window determination means for determining a congestion window for the communication session based on a number of parallel virtual communication sessions that will fully and fairly utilize the bandwidth of the network and a congestion control mechanism of the communication session, the congestion control window determination means further for setting the congestion window for the communication session to the determined congestion window.

14. The computing device of claim 13, further comprising an N-adjuster means for determining the number of parallel virtual communication sessions based on the determined estimation of the network condition and a congestion control mechanism.

15. The computing device of claim 14, wherein the number of parallel virtual communication sessions is periodically updated according to:

16. The computing device of claim 14, wherein the number of parallel virtual communication sessions is periodically updated according to:

17. The computing device of claim 15, wherein

18. The computing device of claim 13, further comprising:

a mechanism selecting means for selecting the congestion control mechanism for the communication session based on the determined estimation of the network condition from a plurality of congestion control mechanisms comprising;

TCP-Reno;

TCP-Vegas;

TCP-Fast;

Compound TCP;

TCP Veno;

TCP Westwood;

TCP Cubic; and

TCP BIC.

19. The computing device of claim 13, wherein determining an estimation of the network condition comprises one or more of:

determining an estimate of network propagation delay between a sender and a receiver of the communication session;

determining an estimate of the number of in-flight packets between the sender and the receiver of the communication session;

determining an estimate of network bandwidth between the sender and the receiver of the communication session; and

determining an estimate of a packet loss rate between the sender and the receiver of the communication session.

20. The computing device of claim 19, wherein:

the estimate of network propagation delay is determined based on the round trip time (RTT) observed by the sender; and

the estimate of the number of in-flight packets is determined based on the RTT and the congestion window.