Network Monitoring System And Method

• US 20080104231A1
• Filed: 11/17/2005
• Published: 05/01/2008
• Est. Priority Date: 11/17/2004
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Mittal, Nishant, Dey, Sujit, Panigrahi, Debashis
• Granted Patent: US 8,010,655 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 43/12 Network monitoring probes
• CPC Class Codes: H04L 43/16 Threshold monitoring

Abstract

A method for monitoring a wireless channel or wireless network. Preferably, the method and system monitors a web-based network. Active data probing is used to estimate bandwidth availability when no a-priori knowledge of the current channel or network condition is available, and passive monitoring is used to track ongoing web traffic in estimating the current bandwidth available. Data probes are selected that are dynamically customized based on application requirements and the network variability observed in view of a balancing between accuracy of the bandwidth estimation and the potential overhead in terms of time consumed and additional traffic used. In this way, under specified limits of overhead, the active probing attempts to achieve best-effort network bandwidth estimation, and the passive monitoring tracks ongoing web traffic in estimating the current bandwidth available.

Claims

1. A method for estimating bandwidth of a network for delivery of data to a client, the method comprising:

generating a data object having a predetermined size;

embedding the data object with a web scripting language for generating a beginning and an ending time stamp, to provide a web page;

sending the provided web page to the client over the network, whereby the web scripting language generates the beginning and the ending time stamp;

receiving the generated beginning and ending time stamp;

estimating bandwidth of the network based on the generated beginning and ending time stamp and the size of the data object.

2. The method of claim 1, wherein the web scripting language comprises JavaScript.

3. The method of claim 1, wherein said generating comprises generating random data.

4. The method of claim 3, wherein the random data is generally incompressible.

5. The method of claim 1, wherein said generating comprises generating a plurality of data objects, each having a predetermined size, and wherein the web scripting language generates a beginning and an ending time stamp for each of the plurality of data objects.

6. The method of claim 1, wherein the network is wireless.

7. The method of claim 1, further comprising:

selecting the predetermined size of the data object based on at least one of variability of the network and network overhead.

8. A method for estimating bandwidth for delivering a requested web page to a client over a network, the method comprising:

receiving the requested web page;

generating one or more passive monitoring data probes using one or more objects in the received web page, each of the generated passive monitoring probes generating a beginning and an ending time stamp when received by a client web browser;

creating one or more active data probes comprising a generated data object of a predetermined size wrapped with a scripting language, each of the active data probes generating a beginning and an ending time stamp when received by the client web browser;

selecting either the generated passive monitoring probes or the created active data probes for sending to the client;

sending the selected probes to the client over the network, whereby the probes generate the beginning and the ending time stamp;

receiving the generated beginning and ending time stamp;

estimating bandwidth of the network based on the generated beginning and ending time stamp and the size of the data object.

9. The method of claim 8, wherein said selecting comprises selecting the generated active data probes when no a-priori knowledge of a current network condition is available.

10. The method of claim 8, wherein said selecting comprises selecting the generated active probes if a standard deviation of previous estimated bandwidths exceeds a predetermined threshold.

11. The method of claim 8, wherein said selecting comprises selecting the generated active probes if a predetermined time has elapsed after a previous generated active probe was sent to the client.

12. The method of claim 8, wherein said generating one or more passive data probes comprises wrapping a web scripting language around one or more selected objects in the received web page, the web scripting language generating a beginning and an ending time stamp when received by the client browser.

13. A system configured to perform the method of claim 8.

14. A server configured to perform the method of claim 8.

15. Machine-readable means for performing the method of claim 8.

16. The method of claim 8, wherein the network is wireless.

17. A method for monitoring a wireless network, the method comprising steps of:

passive monitoring to track ongoing web traffic in estimating bandwidth availability;

active data probing to estimate bandwidth availability when no a-priori knowledge of the current channel or network condition is available;

wherein said active data probing comprises selecting data probes that are dynamically customized based on network variability observed in view of a balancing between accuracy of the bandwidth estimation and the potential overhead in terms of time consumed and additional traffic used, and sending the selected data probes to a client;

wherein under specified limits of overhead, the active probing attempts to achieve best-effort network bandwidth estimation.

18. The method of claim 17, wherein said active probing is conducted again when a wireless condition has changed significantly or the passive monitoring information becomes stale.

19. The method of claim 17, wherein said passive monitoring comprises:

receiving a web page requested by the client;

modifying the received web page by wrapping a web scripting language around one or more selected objects in the received web page for generating, for each selected object, a beginning and ending time stamp;

sending the modified web page to the client;

receiving the beginning and ending time stamp from the client for at least one object;

estimating the network bandwidth based on the received beginning, the ending time stamp, and the size of the at least one object.

20. The method of claim 19, wherein said active data probing comprises:

generating one or more data objects having a predetermined size;

wrapping a web scripting language around the one or more data objects for generating, for each object, a beginning and ending time stamp, to create a new web page;

sending the new web page to the client;

receiving the beginning and ending time stamp from the client for at least one object;

estimating the network bandwidth based on the received beginning, the ending time stamp, and the size of the at least one object.