Apparatus and method for monitoring quality metrics associated with a wireless network

• US 8,559,327 B2
• Filed: 12/17/2010
• Issued: 10/15/2013
• Est. Priority Date: 04/13/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Shim, Choon B.
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Zaidi, Iqbal
• Application Number:
  US12/971,530
• Publication Number:
  US 20110085466A1
• Time in Patent Office: 1,033 Days
• Field of Search: 370252-253, 370/230, 370/235, 370412-427, 370/465, 370503-545, 455/456.1, 455/550.1
• US Class Current: 370/252
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/087 Jitter
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control

Abstract

An apparatus and method for measuring metrics associated with a wireless network is described. One embodiment includes capturing a packet transmitted over a network and determining a minimum delay of a plurality of previously captured packets, where each previously captured packet of the plurality of previously captured packets is associated with a delay. The embodiment further includes determining a current overall delay of the packet based on features of the packet and calculating a congestion indicator based on the current overall delay and the minimum delay.

Claims

1. A method comprising:

capturing a first packet transmitted over a network;

determining, using a processor, an overall delay for each of a plurality of packets captured prior to the capturing of the first packet, the overall delay being a difference between a creation time of a particular packet and a time when the particular packet was captured;

determining a minimum delay by selecting a lowest of the overall delays determined for each of the plurality of packets captured prior to the capturing of the first packet determining an overall delay of the first packet based on features of the first packet; and

calculating a congestion indicator based on the overall delay of the first packet and the minimum delay.

2. The method of claim 1, wherein the overall delays for each of the plurality of packets captured prior to the capturing of the first packet are determined during a calibration time period.

3. The method of claim 1, further comprising calibrating a time clock of a capturing device based on the minimum delay.

4. The method of claim 1, further comprising updating the minimum delay based on the-overall delay of the first packet.

5. The method of claim 1, further comprising associating the congestion indicator with at least one of a terminal that created the packet, a monitoring device that captured the first packet, and a network over which the first packet was transmitted.

6. The method of claim 1, wherein the features of the first packet comprise a creation time of the first packet and a capture time of the first packet.

7. The method of claim 1, wherein the congestion indicator is calculated based on the difference between the overall delay of the first packet and the minimum delay.

8. The method of claim 1, further comprising selecting the first packet from a plurality of packets based on a filter criterion.

9. A system comprising:

a receiver module to receive a first packet transmitted over a network; and

a processor configured to;

determine, using a processor, an overall delay for each of a plurality of packets captured prior to the capturing of the first packet, the overall delay being a difference between a creation time of a particular packet and a time when the particular packet was captured by the receiver module;

determine a minimum delay by selecting a lowest of the overall delays determined for each of the plurality of packets captured prior to the capturing of the first packet;

determine an overall delay of the first packet based on features of the first packet; and

calculate a congestion indicator based on the overall delay of the first packet and the minimum delay.

10. The system of claim 9, wherein the processor is further configured to calibrate a time clock of a capturing device based on the minimum delay.

11. The system of claim 9, wherein the processor is further configured to update the minimum delay based on the overall delay of the first packet.

12. The system of claim 9, wherein the processor is further configured to associate the congestion indicator with at least one of a terminal that created the packet, a monitoring device that captured the first packet, and a network over which the first packet was transmitted.

13. The system of claim 9, further comprising:

a memory configured to store a filter criterion; and

wherein the processor is further to select the first packet from a plurality of packets based on the filter criterion.

14. One or more non-transitory computer readable storage media encoded with software comprising computer executable instructions and when the software is executed operable to:

capture a first packet transmitted over a network;

determine, using a processor, an overall delay for each of a plurality of packets captured prior to the capturing of the first packet, the overall delay being a difference between a creation time of a particular packet and a time when the particular packet was captured;

determine a minimum delay by selecting a lowest of the overall delays determined for each of the plurality of packets captured prior to the capturing of the first packet;

determine an overall delay of the first packet based on features of the first packet; and

calculate a congestion indicator based on the overall delay of the first packet and the minimum delay.

15. The one or more computer readable storage media of claim 14, wherein the software is executed operable further to calibrate a time clock of a capturing device based on the minimum delay.

16. The one or more computer readable storage media of claim 14, wherein the software is executed operable further to update the minimum delay based on the overall delay of the first packet.

17. A system comprising:

a receiver module to receive a first packet transmitted over a network;

means for determining. using a processor, an overall delay for each of a plurality of packets captured prior to the capturing of the first packet, the overall delay being a difference between a creation time of a particular packet and a time when the particular packet was captured by the receiver module;

the processor for determining a minimum delay by selecting a lowest of the overall delays determined for each of the plurality of packets captured prior to the capturing of the first packet;

means for determining, using the processor, an overall delay of the first packet based on features of the first packet; and

means for calculating, using the processor, a congestion indicator based on the overall delay of the first packet and the minimum delay.