Detecting Irregular Retransmissions

• US 20110103256A1
• Filed: 10/30/2009
• Published: 05/05/2011
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.), Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Qian, Feng, Mao, Zhuoqing, Spatscheck, Oliver, Gerber, Alexandre, Sen, Subhabrata, Willinger, Walter
• Granted Patent: US 8,817,653 B2
• Time in Patent Office: Days
• US Class Current: 370/253
• CPC Class Codes: H04L 43/04 Processing captured monitoring data, e.g. for logfile generation
• CPC Class Codes: H04L 43/045 for graphical visualisation of monitoring data
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters

Abstract

A packet trace is received. Transmitted bytes and retransmitted bytes are identified in the packet trace. Upon identifying the transmitted bytes and the retransmitted bytes in the packet trace, one or more time-rate pairs are determined from the packet trace. The time-rate pairs are plotted on a rate tracking graph.

Claims

1. A computer-implemented method for detecting an irregular retransmission, the method comprising computer-implemented operations for:

receiving, through a computer, a packet trace;

identifying transmitted bytes and retransmitted bytes in the packet trace;

upon identifying the transmitted bytes and the retransmitted bytes in the packet trace, determining one or more time-rate pairs from the packet trace; and

plotting the time-rate pairs on a rate tracking graph.

2. The computer-implemented method of claim 1, wherein the packet trace comprises a unidirectional packet trace.

3. The computer-implemented method of claim 1, the method further comprising:

determining a correlation coefficient based on the plotted rate tracking graph; and

detecting the irregular transmission based on the correlation coefficient.

4. The computer-implemented method of claim 3, wherein the irregular transmission is detected when the correlation coefficient is below a threshold.

5. The computer-implemented method of claim 1, wherein determining one or more time-rate pairs from the packet trace comprises:

determining a window size of a tracking window, the window size specifying a number of transmitted bytes;

sliding the tracking window along the packet trace until the tracking window encompasses the number of transmitted bytes as specified by the window size; and

determining the time-rate pairs based on a portion of the packet trace encompassed by the tracking window.

6. The computer-implemented method of claim 5, wherein each of the time-rate pairs comprises a retransmission rate and a time to successfully transfer a fixed size of data based on the portion of the packet trace encompassed by the tracking window.

7. The computer-implemented method of claim 1, the method further comprising removing large inter-arrival times in the packet trace.

8. A system for detecting an irregular retransmission, comprising:

a memory for storing a program containing code for detecting the irregular retransmission; and

a processor functionally coupled to the memory, the processor being responsive to computer-executable instructions contained in the program and configured to

receive a packet trace,

identify transmitted bytes and retransmitted bytes in the packet trace,

upon identifying the transmitted bytes and the retransmitted bytes in the packet trace, determine one or more time-rate pairs from the packet trace, and

plot the time-rate pairs on a rate tracking graph.

9. The system of claim 8, wherein the packet trace comprises a unidirectional packet trace.

10. The system of claim 8, wherein the processor is further configured to

determine a correlation coefficient based on the plotted rate tracking graph, and

detect the irregular transmission based on the correlation coefficient.

11. The system of claim 10, wherein the irregular transmission is detected when the correlation coefficient is below a threshold.

12. The system of claim 8, wherein to determine one or more time-rate pairs from the packet trace, the processor is further configured to

determine a window size of a tracking window, the window size specifying a number of transmitted bytes,

slide the tracking window along the packet trace until the tracking window encompasses the number of transmitted bytes as specified by the window size, and

determine the time-rate pairs based on a portion of the packet trace encompassed by the tracking window.

13. The system of claim 12, wherein each of the time-rate pairs comprises a retransmission rate and a time to successfully transfer a fixed size of data based on the portion of the packet trace encompassed by the tracking window.

14. A computer-readable medium having instructions stored thereon for execution by a processor to provide a method for detecting an irregular retransmission, the method comprising:

receiving, through a computer, a packet trace;

identifying transmitted bytes and retransmitted bytes in the packet trace;

upon identifying the transmitted bytes and the retransmitted bytes in the packet trace, determining one or more time-rate pairs from the packet trace; and

plotting the time-rate pairs on a rate tracking graph.

15. The computer-readable medium of claim 14, wherein the packet trace comprises a unidirectional packet trace.

16. The computer-readable medium of claim 14, the method further comprising:

determining a correlation coefficient based on the plotted rate tracking graph; and

detecting the irregular transmission based on the correlation coefficient.

17. The computer-readable medium of claim 15, wherein the irregular transmission is detected when the correlation coefficient is below a threshold.

18. The computer-readable medium of claim 14, wherein determining one or more time-rate pairs from the packet trace comprises:

determining a window size of a tracking window, the window size specifying a number of transmitted bytes;

sliding the tracking window along the packet trace until the tracking window encompasses the number of transmitted bytes as specified by the window size; and

determining the time-rate pairs based on a portion of the packet trace encompassed by the tracking window.

19. The computer-readable medium of claim 18, wherein each of the time-rate pairs comprises a retransmission rate and a time to successfully transfer a fixed size of data based on the portion of the packet trace encompassed by the tracking window.

20. The computer-readable medium of claim 14, the method further comprising removing large inter-arrival times in the packet trace.