Dynamic adjustment of receive window utilized by a transmitting device

Patent metadata

Field	Value
Publication number	US-9253104-B2
Application number	US-201414256836-A
Country	US
Kind code	B2
Filing date	Apr 18, 2014
Priority date	Mar 3, 2010
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A method of controlling size of a receive window includes transmitting packets over a communication channel from a transmitting device to a receiver, and receiving acknowledgment packets from the receiver, the received acknowledgement packets from the receiver including an advertised receive window size. The method further includes determining a backlog parameter for the receiver in accordance with the advertised receive window size, determining a queuing delay in accordance the received acknowledgment packets, resetting a size of a congestion window in accordance with a function of a current size of the congestion window and a factor proportional to the queuing delay, and resetting a size of a receive window in accordance with a function of a current size of the receive window and the backlog parameter. A network window is reset in accordance with the smaller of the size of the congestion window and the size of the receive window.

First claim

What is claimed is:

1. A method of controlling transmission of messages from a sender to a recipient over a network, comprising:
at a transmitting device:
receiving acknowledgment packets from the receiver corresponding to transmitted packets, the received acknowledgement packets from the receiver including an advertised receive window size;
determining a backlog parameter for the receiver in accordance with the advertised receive window size in the received acknowledgment packets;
determining a queuing delay in accordance the received acknowledgment packets;
resetting a size of a congestion window in accordance with a function of a current size of the congestion window and a factor proportional to the queuing delay;
resetting a size of a receive window in accordance with a function of a current size of the receive window and the backlog parameter, wherein the receive window has a dynamically determined size, distinct from the advertised receive window size in the acknowledgment packets received from the receiver;
comparing the size of the congestion window and the size of the receive window;
resetting a size of a network window in accordance with the smaller of the size of the congestion window and the size of the receive window; and
transmitting packets over the network to the recipient in accordance with the size of the network window.

2. The method of claim 1 , wherein determining the backlog parameter includes determining the backlog parameter for the receiver in accordance with a difference between the advertised receive window size packets and a predefined fraction of a receive buffer size, the receive buffer size corresponding to a size, or estimated size, of a receive buffer in the receiver.

3. The method of claim 1 , including:
determining a current round trip time for the transmitted packets; and
resetting the size of the receive window in accordance with a scaling factor, the current round trip time, the current size of the receive window and the backlog parameter.

4. The method of claim 3 , including determining the scaling factor, wherein the scaling factor is a nominal round trip time.

5. The method of claim 3 , including determining the scaling factor, wherein when the backlog parameter's value corresponds to a backlog at the receiver that is greater than a predefined threshold, the scaling factor has a first value, and when the backlog parameter's value corresponds to a backlog at the receiver that is less than the predefined threshold, the scaling factor has a second value that is less than the first value.

6. The method of claim 1 , including:
determining a current round trip time for the transmitted packets; and
resetting the size of the receive window in accordance with a sum of the current round trip time and a value produced by multiplying a scaling factor with a ratio of the backlog parameter to the current size of the receive window.

7. The method of claim 1 , wherein resetting the size of the receive window includes maintaining the current size of the receive window when the backlog parameter is within a predefined value range.

8. The method of claim 1 , including determining a current round trip time for the transmitted packets, and resetting the size of the receive window only once every other round trip time.

9. The method of claim 1 , including resetting the size of the receive window periodically.

10. An apparatus for controlling transmission of messages from a sender to a recipient over a network, comprising:
one or more processors; and
memory that stores one or more programs for execution by the one or more processors, the one or more programs including instructions for:
receiving acknowledgment packets from the receiver corresponding to transmitted packets, the received acknowledgement packets from the receiver including an advertised receive window size;
determining a backlog parameter for the receiver in accordance with the advertised receive window size in the received acknowledgment packets;
determining a queuing delay in accordance the received acknowledgment packets;
resetting a size of a congestion window in accordance with a function of a current size of the congestion window and a factor proportional to the queuing delay;
resetting a size of a receive window in accordance with a function of a current size of the receive window and the backlog parameter, wherein the receive window has a dynamically determined size, distinct from the advertised receive window size in the acknowledgment packets received from the receiver;
comparing the size of the congestion window and the size of the receive window;
resetting a size of a network window in accordance with the smaller of the size of the congestion window and the size of the receive window; and
transmitting packets over the network to the recipient in accordance with the size of the network window.

11. The apparatus of claim 10 , wherein the instructions for determining the backlog parameter include instructions for determining the backlog parameter for the receiver in accordance with a difference between the advertised receive window size packets and a predefined fraction of a receive buffer size, the receive buffer size corresponding to a size, or estimated size, of a receive buffer in the receiver.

12. The apparatus of claim 10 , the one or more programs including:
instructions for determining a current round trip time for the transmitted packets; and
instructions for resetting the size of the receive window in accordance with a scaling factor, the current round trip time, the current size of the receive window and the backlog parameter.

13. The apparatus of claim 12 , the one or more programs including instructions for determining the scaling factor, wherein the scaling factor is a nominal round trip time.

14. The apparatus of claim 12 , the one or more programs including instructions for determining the scaling factor, wherein when the backlog parameter's value corresponds to a backlog at the receiver that is greater than a predefined threshold, the scaling factor has a first value, and when the backlog parameter's value corresponds to a backlog at the receiver that is less than the predefined threshold, the scaling factor has a second value that is less than the first value.

15. The apparatus of claim 10 , the one or more programs including:
instructions for determining a current round trip time for the transmitted packets; and
instructions for resetting the size of the receive window in accordance with a sum of the current round trip time and a value produced by multiplying a scaling factor with a ratio of the backlog parameter to the current size of the receive window.

16. The apparatus of claim 10 , wherein the instructions for resetting the size of the receive window include instructions for maintaining the current size of the receive window when the backlog parameter is within a predefined value range.

17. The apparatus of claim 10 , the one or more programs including instructions for determining a current round trip time for the transmitted packets, and instructions for resetting the size of the receive window only once every other round trip time.

18. The apparatus of claim 10 , the one or more programs including instructions for resetting the size of the receive window periodically.

Assignees

• Akamai Tech Inc

Inventors

• Jin Cheng
• Lee George S
• Low Steven
• Ng Darren
• Witt Ryan

Classifications

• H04L47/30

  in combination with information about buffer occupancy at either end or at transit nodes · CPC title

• H04L47/27 Primary

  Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets · CPC title

• H04L12/26

  Electricity · mapped topic

• H04L12/56

  Packet switching systems · CPC title

• H04L43/00

  Arrangements for monitoring or testing data switching networks · CPC title