METHODS AND SYSTEMS FOR SLIDING BUBBLE CONGESTION CONTROL

• US 20120236718A1
• Filed: 03/02/2012
• Published: 09/20/2012
• Est. Priority Date: 03/02/2011
• Status: Active Grant

• Current Assignee: DMP Holdings Limited
• Original Assignee: Mobidia Technology Inc. (Data AI Incorporated)
• Inventors: GREWAL, Avininder Pal Singh, NOUREDDIN, Sina K., LENTERS, Allison Courtney
• Granted Patent: US 8,724,471 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 1/1678 where the control information is for timing, e.g. time stamps
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/187 Details of sliding window management
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• 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 47/41 by acting on aggregated flows or links

Abstract

A transmission method for multiple TCP sessions with the same host including methods for congestion control and retransmission of lost segments.

Claims

1. A transmission method for multiple TCP sessions with the same host, comprising:

providing a congestion bubble comprising a two-dimensional buffer volume; and

allocating different sessions to different portions of the congestion bubble during a transmission event for multiple sessions.

2. The method of claim 1, wherein the area of the congestion bubble is approximately the same as a target flight-size.

3. The method of claim 1, further comprising:

setting the amount of data to be sent equal to the current size of the congestion bubble less the current flight-size estimate when a current size of the congestion bubble is greater than a current flight-size estimate

4. The method of claim 1, further comprising:

setting the amount of data to be sent equal to the smallest of the current size of the congestion bubble and the amount of dropped data when a current size of the congestion bubble is less than a current flight-size estimate and the dropped data is greater than zero.

5. The method of claim 3, further comprising:

setting a transmit bandwidth equal to the largest of the current size of the congestion bubble and the slow start threshold divided by the minimum round trip time.

6. The method of claim 4, further comprising:

setting a transmit bandwidth equal to the largest of the current size of the congestion bubble and the slow start threshold divided by the minimum round trip time.

7. The method of claim 1, further comprising:

characterizing the transmission event as one of (i) initial transmission of data, (ii) retransmission of data, (iii) acknowledgement of data received, and (iv) dropped data;

incrementing the current flight-size estimate for the initial transmission of data or the acknowledgement of data received;

incrementing the current flight-size estimate and decrementing the amount of dropped data for the retransmission of data; and

decrementing the current flight-size estimate and incrementing the amount of dropped data for the dropped data.

8. The method of claim 1, further comprising:

retransmitting unacknowledged segments if the current size of the congestion bubble is less than a flight-size estimate.

9. The method of claim 8, further comprising:

entering a session recovery state when the current time minus the start time for the retransmission timeout is greater than a stored value for the retransmission timeout.

10. The method of claim 9, further comprising:

setting a recovery window, entering a slow start mode, and increasing the retransmission timeout when all sessions have a retransmission timeout; and

setting a recovery window, reducing the size of the congestion bubble, and entering a fast recovery mode when fewer than all sessions have a retransmission timeout.

11. A non-transitory computer readable storage medium having executable instructions for performing a transmission method for multiple TCP sessions with the same host, comprising:

providing a congestion bubble comprising a two-dimensional buffer volume; and

allocating different sessions to different portions of the congestion bubble during a transmission event for multiple sessions.

12. The computer readable storage medium of claim 11, further comprising:

setting the amount of data to be sent equal to the current size of the congestion bubble less the current flight-size estimate when a current size of the congestion bubble is greater than a current flight-size estimate

13. The computer readable storage medium of claim 11, further comprising:

setting the amount of data to be sent equal to the smallest of the current size of the congestion bubble and the amount of dropped data when a current size of the congestion bubble is less than a current flight-size estimate and the dropped data is greater than zero.

14. The computer readable storage medium of claim 11, further comprising:

setting a transmit bandwidth equal to the largest of the current size of the congestion bubble and the slow start threshold divided by the minimum round trip time.

15. The computer readable storage medium of claim 11, further comprising:

setting a transmit bandwidth equal to the largest of the current size of the congestion bubble and the slow start threshold divided by the minimum round trip time.

16. A system for controlling the transmission of data in multiple TCP sessions with the same host, comprising:

a server having a transmit scheduler and a congestion control module,

wherein the transmit scheduler determines how much data a session is allowed to transmit and how much bandwidth to allocate to the session, and

wherein the congestion control module provides a congestion bubble comprising a two-dimensional buffer volume and allocates different sessions to different portions of the congestion bubble during a transmission event for multiple sessions.

17. The system of claim 16, wherein the transmit scheduler sets the amount of data to be sent equal to the current size of the congestion bubble less the current flight-size estimate when a current size of the congestion bubble is greater than a current flight-size estimate

18. The system of claim 16, wherein the transmit scheduler sets the amount of data to be sent equal to the smallest of the current size of the congestion bubble and the amount of dropped data when a current size of the congestion bubble is less than a current flight-size estimate and the dropped data is greater than zero.

19. The system of claim 16, wherein the transmit scheduler sets a transmit bandwidth equal to the largest of the current size of the congestion bubble and the slow start threshold divided by the minimum round trip time.