Congestion control system

• US 7,512,066 B2
• Filed: 03/30/2004
• Issued: 03/31/2009
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Turner, Yoshio, Santos, Jose Renato, Janakiraman, Gopalakrishnan
• Primary Examiner(s): Qureshi; Afsar M.
• Application Number:
  US10/814,073
• Publication Number:
  US 20050226150A1
• Time in Patent Office: 1,827 Days
• Field of Search: 370/229, 370230-237, 370/392, 370/389, 370/395.64, 370/253, 370400-402, 455/450, 455/455, 709/235
• US Class Current: 370/230
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/26 using explicit feedback to the source, e.g. choke packets
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/29 using a combination of thresholds

Abstract

According to the present invention, there is provided a method for controlling congestion in a communications network, the method including receiving congestion feedback data relating to said network, adjusting at least one of a window limit and a rate limit based on said congestion feedback data and injecting data packets onto said network according to said window limit and said rate limit.

Claims

1. A method for controlling congestion in a communications network, including:

receiving congestion feedback data from acknowledgement packets transmitted in said network;

using the acknowledgement packets to determine which of a window limit and a rate limit are causing congestion in the network;

adjusting both the window limit and the rate limit based on said congestion feedback data to reduce network congestion; and

injecting data packets onto said network according to both said window limit and said rate limit, wherein the window limit controls a number of packets in transit between source and destination nodes and the rate limit controls a rate at which the source node injects packets into the communications network.

2. A method according to claim 1, wherein said adjusting includes:

decreasing said rate limit and said window limit if said network is determined to be congested based on said congestion feedback data.

3. A method according to claim 1, wherein said adjusting includes:

increasing, based on a limiting factor, at least one of said rate limit and said window limit if said network is determined not to be congested based on said congestion feedback data.

4. A method according to claim 3, wherein said limiting factor is determined based on whether a transmission of a data packet was most recently limited by at least one of said rate limit and said window limit.

5. A method according to claim 4, wherein said race limit is increased if said limiting factor is determined by said rate limit.

6. A method according to claim 4, wherein said window limit is increased if said limiting factor is determined by said window limit.

7. A method according to claim 4, wherein both said rate limit and said window limit is increased if said limiting factor is determined by both said rate limit and said window limit.

8. A method according to claim 4, wherein said limiting factor is a value between a predetermined high threshold and a predetermined low threshold.

9. A method according to claim 4, wherein said determining of said limiting factor includes increasing or decreasing said limiting factor by an amount corresponding to a size of the data packet for which injection was limited.

10. A method according to claim 9, wherein said limiting factor is increased by said amount if the transmission of a data packet was limited by said window limit.

11. A method according to claim 9, wherein said limiting factor is decreased by said amount if the transmission of a data packet was limited by said rate limit.

12. A method according to claim 1, wherein said adjusting is performed by an Additive Increase Multiplicative Decrease response process.

13. A system for controlling congestion in a communications network, including:

a congestion control module that adjusts at least one of a window limit and a rate limit based on congestion feedback data from acknowledgement packets in said network, uses the acknowledgment packets to determine which of said window limit and said rate limit cause congestion in said network, and limits injection of packets into said network according to both said window limit and said rate limit, wherein the window limit controls a number of packets in transit between source and destination nodes and the rate limit controls a rate at which the source node injects packets into the communications network.

14. A system according to claim 13, wherein said congestion control module is adapted to decrease said rate limit and said window limit if said network is determined to be congested based on said congestion feedback data.

15. A system according to claim 13, wherein said congestion control module is adapted to increase, based on a limiting factor, at least one of said rate limit and said window limit if said network is determined not to be congested based on said congestion feedback data.

16. A system according to claim 15, further including means for determining said limiting factor based on whether a transmission of a data packet was most recently limited by at least one of said rate limit and said window limit.

17. A system for controlling congestion in a communications network, comprising:

means for receiving congestion feedback data from acknowledgement packets transmitted in said network;

means for using the congestion feedback data from the acknowledgement packets to determine which of a window limit and a rate limit are causing congestion in the network;

means for adjusting at least one of the window limit and the rate limit based on said congestion feedback data; and

means for injecting data packets onto said network according to both said window limit and said rate limit.

18. A system according to claim 17, wherein said means for adjusting includes:

means for decreasing said rate limit and said window limit if said network is determined to be congested based on said congestion feedback data.

19. A system according to claim 17, wherein said means for adjusting includes:

means for increasing, based on a limiting factor, at least one of said rate limit and said window limit if said network is determined not to be congested based on said congestion feedback data.

20. A system according to claim 19, wherein said limiting factor is determined based on whether a transmission of a data packet was most recently limited by at least one of said rate limit and said window limit.