Method and apparatus for monitoring latency, jitter, packet throughput and packet loss ratio between two points on a network

• US 7,961,637 B2
• Filed: 06/07/2004
• Issued: 06/14/2011
• Est. Priority Date: 06/07/2004
• Status: Active Grant

• Current Assignee: Spirent Communications of Rockville, Inc. (Spirent Communications Incorporated)
• Original Assignee: Spirent Communications of Rockville, Inc. (Spirent Communications Incorporated)
• Inventors: McBeath, Tom
• Primary Examiner(s): Wu; Jianye
• Application Number:
  US10/862,959
• Publication Number:
  US 20050270982A1
• Time in Patent Office: 2,563 Days
• Field of Search: 370/252
• US Class Current: 370/252
• CPC Class Codes: H04L 1/205 jitter monitoring
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/0852 Delays
• 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

Abstract

A system for testing a segment of a data-packet-network has a first probe connected substantially at one end of the segment; a second probe connected substantially at the opposite end of the segment from the location of the first probe; and a process application distributed to each probe. The first and second probes collect data from and time stamp data packets as they pass forming first and second records of the individual packets whereupon the second-formed records of each packet are compared with the first records of each packet for record matching, time-stamp comparison and test result processing.

Claims

1. A system for testing a segment of a data-packet-network comprising:

a first probe connected substantially at one end of the segment;

a second probe connected substantially at the opposite end of the segment from the location of the first probe; and

a process application distributed to each probe;

characterized in that the probes form a direct data path for bidirectional packet exchange from one end of the segment to the opposite end of the segment having two data exchange points on the segment and the first and second probes at said ends collect data from and time stamp data packets as they pass forming first and second records of the individual packets at the probes whereupon the second-formed records of each packet are compared with the first records of each packet at the probes for record matching, time-stamp comparison and test result processing.

2. The system of claim 1 wherein the data-packet-network supports one or both of a transport control protocol and of a real-time transport protocol-capable network.

3. The system of claim 1 wherein the data-packet-network is the Internet network.

4. The system of claim 1 wherein the data-packet-network is an Ethernet network.

5. The system of claim 1 wherein probes are one or a combination of desktop computers, network routers or network servers having permanent or temporary access to the data packet network.

6. The system of claim 1 wherein, the probes are dedicated units programmed for line testing.

7. The system of claim 1 wherein, the probes are software components distributed to selected end nodes.

8. The system of claim 1 wherein, the probes are firmware components distrusted to selected end nodes.

9. The system of claim 8 wherein the firmware components include instructions for performing a testing sequence.

10. The system of claim 1 wherein the result processing produces an average latency value for the segment.

11. The system of claim 1 wherein the result processing produces an average jitter value for the segment.

12. The system of claim 1 wherein the result processing produces an average packet-loss ratio value of the segment.

13. The system of claim 1 wherein the result processing produces an average data throughput value of the segment.

14. The system of claim 1 wherein the segment defines a network line between two end nodes.

15. The system of claim 1 wherein the segment defines an MPLS tunnel.

16. The system of claim 1 wherein the segment defines a network line wherein the probes are not the final destination for the packets, but test a segment of the network line between two nodes in the network.

17. A method for testing a segment of a data-packet-network comprising:

(a) establishing a probe at one end of the segment and a probe at the opposite end of the segment the probes forming a direct data path for bidirectional packet exchange between the one end of the segment to the opposite end of the segment and;

(b) capturing data from data packets traveling the length of the segment one time at each probe of the pair of probes;

(c) recording the captured data at the probes and time-stamping each record formed;

(d) sharing records formed by one probe with the other probe, the records shared by either probe in the record forming sequence;

(e) matching the shared records each probe;

(f) comparing the time-stamp information of the matching records; and

(g) processing the comparison results for the aggregate of matches to produce resulting test values for the segment tested.

18. The method of claim 17 wherein the data-packet-network supports one or both of transport control protocol and real-time transport protocol.

19. The method of claim 17 wherein the data-packet-network is one of an IP network or an Ethernet network.

20. The method of claim 17 wherein in step (a) the probes are one or a combination of desktop computers, network routers, network severs having permanent or temporary access to the data packet network.

21. The method of claim 17 wherein in step (a) the probes are dedicated units programmed for line testing.

22. The method of claim 17 wherein in step (a) the probes are software components distributed to selected end nodes.

23. The method of claim 17 wherein in step (a) the probes are firmware components distributed to selected end nodes.

24. The method of claim 17 wherein in step (b) the data captured includes source ID, destination ID, and sequence number of each packet selected for data capture.

25. The method of claim 17 wherein in step (c) the records are stored in a data cache maintained by each probe.

26. The method of claim 17 wherein in step (d) the records are shared via a control plane link between the probes.

27. The method of claim 17 wherein in step (e) the records are matched according to the unique set of source ID, destination ID and sequence number.

28. The method of claim 17 wherein in step (f) a latency value is produced as a result value for each matching record having two timestamps to compare.

29. The method of claim 17 wherein in step (g) the aggregate defines all of the records currently held in storage the results valid for the period of testing.