Sampling test of network performance

• US 20070195707A1
• Filed: 02/22/2006
• Published: 08/23/2007
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Viola Networks, Ltd.
• Inventors: Cidon, Israel, Zangiri, Benny, Sidi, Moshe, Horn, Lior
• Granted Patent: US 7,990,887 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A method for testing a communication network includes transmitting a flow of test packets over a path through the network. The flow includes a series of bursts of the test packets separated by intervals having an interval duration, each burst comprising a sequence of the test packets and having a burst duration less than the interval duration. Arrival characteristics of the test packets in the flow are measured at a receiving end of the path. The arrival characteristics include at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic. A quality defect in the network is detected based on the measured arrival characteristics.

Claims

1. A method for testing a communication network, comprising:

transmitting a flow of test packets over a path through the network, the flow comprising a series of bursts of the test packets separated by intervals having an interval duration, each burst comprising a sequence of the test packets and having a burst duration less than the interval duration;

measuring arrival characteristics of the test packets in the flow at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic; and

detecting a quality defect in the network based on the measured arrival characteristics.

2. The method according to claim 1, wherein transmitting the flow comprises generating the test packets so as to emulate, within each burst, packet transmission characteristics of a specified real-time protocol.

3. The method according to claim 2, wherein generating the test packets comprises determining a packet size and data rate of the test packets within each burst so as to emulate a codec used in the real-time protocol.

4. The method according to claim 3, wherein the real-time protocol comprises a Voice over IP (VoIP) protocol.

5. The method according to claim 1, wherein the burst duration is no more than one tenth of the interval duration.

6. The method according to claim 1, wherein the burst duration is no more than 1 sec.

7. The method according to claim 1, wherein each burst comprises no more than fifty of the test packets.

8. The method according to claim 1, wherein detecting the quality defect comprises computing a statistical feature of the arrival characteristics of the test packets over the series of the bursts while disregarding the arrival characteristics of one or more initial test packets in each burst.

10. The method according to claim 1, wherein transmitting the test flow comprises transmitting the test flow periodically, concurrently with transmission of user traffic through the network

11. A method for testing a communication network, comprising:

transmitting a burst of test packets over a path through the network, the burst comprising a sequence of no more than fifty of the test packets and having a burst duration no greater than 1 sec;

measuring arrival characteristics of the test packets in the burst at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic; and

detecting a quality defect in the network based on the measured arrival characteristics.

12. Apparatus for testing a communication network, comprising:

first and second traffic agents, which are coupled to respective end points of a path through the network; and

a testing center, which is coupled to instruct at least the first traffic agent to transmit a flow of test packets over the path through the network, the flow comprising a series of bursts of the test packets separated by intervals having an interval duration, each burst comprising a sequence of the test packets and having a burst duration less than the interval duration, and to instruct at least the second traffic agent to measure arrival characteristics of the test packets in the flow at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic, wherein the testing center is adapted to detect a quality defect in the network based on the measured arrival characteristics.

13. The apparatus according to claim 12, wherein the test packets are generated so as to emulate, within each burst, packet transmission characteristics of a specified real-time protocol.

14. The apparatus according to claim 13, wherein a packet size and data rate of the test packets within each burst are chosen so as to emulate a codec used in the real-time protocol.

15. The apparatus according to claim 12, wherein the testing center is arranged to compute a statistical feature of the arrival characteristics of the test packets over the series of the bursts while disregarding the arrival characteristics of one or more initial test packets in each burst.

16. Apparatus for testing a communication network, comprising:

first and second traffic agents, which are coupled to respective end points of a path through the network; and

a testing center, which is coupled to instruct at least the first traffic agent to transmit a burst of test packets over a path through the network, the burst comprising a sequence of no more than fifty of the test packets and having a burst duration no greater than 1 sec, and to instruct at least the second traffic agent to measure arrival characteristics of the test packets in the burst at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic, wherein the testing center is adapted to detect a quality defect in the network based on the measured arrival characteristics.

17. A computer software product for testing a communication network in conjunction with first and second traffic agents, which are coupled to respective end points of a path through the network, the product comprising a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to instruct at least the first traffic agent to transmit a flow of test packets over the path through the network, the flow comprising a series of bursts of the test packets separated by intervals having an interval duration, each burst comprising a sequence of the test packets and having a burst duration less than the interval duration, and to instruct at least the second traffic agent to measure arrival characteristics of the test packets in the flow at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic, wherein the instructions cause the computer to detect a quality defect in the network based on the measured arrival characteristics.

18. The product according to claim 17, wherein the test packets are generated so as to emulate, within each burst, packet transmission characteristics of a specified real-time protocol.

19. The product according to claim 18, wherein a packet size and data rate of the test packets within each burst are chosen so as to emulate a codec used in the real-time protocol.

20. The product according to claim 17, wherein the instructions cause the computer to compute a statistical feature of the arrival characteristics of the test packets over the series of the bursts while disregarding the arrival characteristics of one or more initial test packets in each burst.

21. A computer software product for testing a communication network in conjunction with first and second traffic agents, which are coupled to respective end points of a path through the network, the product comprising a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to instruct at least the first traffic agent to transmit a burst of test packets over a path through the network, the burst comprising a sequence of no more than fifty of the test packets and having a burst duration no greater than 1 sec, and to instruct at least the second traffic agent to measure arrival characteristics of the test packets in the burst at a receiving end of the path, the arrival characteristics comprising at least one of a packet loss characteristic, a packet delay characteristic, and a packet jitter characteristic, wherein the instructions cause the computer to detect a quality defect in the network based on the measured arrival characteristics.