Fault location and performance testing of communication networks

• US 6,269,330 B1
• Filed: 10/01/1998
• Issued: 07/31/2001
• Est. Priority Date: 10/07/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Attune Networks Limited
• Inventors: Cidon, Israel, Sidi, Moshe
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): LAMARRE, GUY J
• Application Number:
  US09/164,488
• Time in Patent Office: 1,034 Days
• Field of Search: 714/712, 714/716, 714/25, 714/31, 714/43, 714/26, 395/200.54, 370/13, 370/241, 370/248, 455/424, 455/423, 455/67.4, 455/69, 455/70, 379/5, 379/9, 379/265, 379/266-267, 379/27, 379/34, 379/4, 379/28, 702/122, 709/223-225, 709/238
• US Class Current: 714/43
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/046 comprising network management agents or mobile agents therefor
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A method and apparatus for testing a network having a plurality of nodes. The method includes sending commands to one or more traffic agents connected to the network and to at least one network management agent coupled to a respective node of the network, transmitting data from at least one of the traffic agents over the network responsive to the commands, determining network information at the at least one network management agent responsive to the commands and to transmission of the data through the respective node, and receiving and evaluating the network information to assess a state of the network.

Claims

1. A method for testing a network having a plurality of nodes, comprising:

sending commands to one or more traffic agents connected to the network and to at least one network management agent coupled to a respective node of the network;

transmitting data from at least one of the traffic agents over the network to a destination responsive to the commands;

determining network information at the at least one network management agent responsive to the commands and to transmission of the data through the respective node, intermediate the at least one of the traffic agents and the destination; and

receiving and evaluating the network information to assess a state of the network.

2. A method according to claim 1, wherein sending the commands comprises sending commands to the one or more traffic agents and to the at least one network management agent from a single source.

3. A method according to claim 1, wherein sending the commands comprises sending commands over the network.

4. A method according to claim 1, wherein the destination comprises a second one of the traffic agents, and comprising receiving at least some of the transmitted data at the destination and deriving additional network information at the second traffic agent, responsive to the commands.

5. A method according to claim 4, wherein deriving the additional network information comprises determining a response time property of the transmitted data.

6. A method according to claim 1, wherein determining network information comprises capturing data transmitted by at least one of the plurality of the traffic agents.

7. A method according to claim 1, wherein transmitting the data comprises multicasting the data.

8. A method according to claim 1, wherein sending the commands comprises sending a pre-stored subscript of commands.

9. A method according to claim 8, wherein sending the subscript comprises sending a subscript which includes execution times for at least some of the commands.

10. A method according to claim 8, wherein sending the subscript comprises sending a subscript which is written in accordance with a general programming language.

11. A method according to claim 1, wherein sending the commands to the at least one network management agent comprises sending commands according to a public network management standard.

12. A method according to claim 1, wherein sending the commands comprises sending commands in accordance with a script.

13. A method according to claim 12, wherein sending the commands comprises initiating the script responsive to an alarm generated by the network.

14. A method according to claim 13, wherein initiating the script comprises initiating the script responsive to an alarm generated by a network management system.

15. A method according to claim 12, wherein the script comprises instructions to be performed in a plurality of test stages, and wherein at least one of the test stages is chosen responsive to results of a previous test stage.

16. A method according to claim 1, wherein sending the commands comprises sending at least one of the commands responsive to the received network information.

17. A method according to claim 16, wherein sending the at least one of the commands comprises sending commands responsive to a measure of an amount of traffic passing through the network.

18. A method according to claim 1, and comprising sending a command to a network management agent to change a traffic characteristic of the network at one or more of the plurality of nodes.

19. A method according to claim 18, wherein changing the traffic characteristic comprises altering the operability of a link of the network.

20. A method according to claim 19, wherein evaluating the network information to assess the state of the network comprises determining whether a first part of the network operates properly by disabling a second part of the network and transmitting the data through the first part while the second part is disabled.

21. A method according to claim 1, wherein transmitting the data comprises transmitting data according to a statistical transmission time pattern.

22. A method according to claim 1, wherein transmitting the data comprises transmitting a request to establish a communication connection.

23. A method according to claim 1, wherein transmitting the data comprises transmitting data in accordance with a standard application protocol.

24. A method according to claim 23, wherein evaluating the network information comprises determining whether a fault in the network is in the application or in the network.

25. A method according to claim 1, wherein transmitting the data comprises transmitting at least one packet of data which includes one or more fields of test information.

26. A method according to claim 25, wherein the test information comprises a time stamp, a sequence number or a connection identification.

27. A method according to claim 25, and comprising receiving the transmitted data at one of the traffic agents and determining network-related performance information at the traffic agent which received the transmitted data responsive to the commands and the test information.

28. A method according to claim 1, wherein evaluating the network information to assess the state of the network comprises locating a network fault.

29. Apparatus for testing a network having a plurality of nodes, comprising:

a plurality of traffic agents which generate and transmit data over the network;

one or more network management agents coupled to respective nodes of the network intermediate the traffic agents, which determine network information at the respective nodes; and

a testing center which sends commands to the plurality of traffic agents to generate and transmit the data and to the one or more network management agents to determine the network information responsive to transmission of the data through the respective nodes, and which receives and evaluates the network information from the one or more network management agents so as to assess performance of the network responsive to the transmitted data.

30. Apparatus according to claim 29, wherein the testing center sends the commands over the network.

31. Apparatus according to claim 29, wherein at least one of the traffic agents receives the transmitted data and derives additional network information, responsive to commands from the testing center.

32. Apparatus according to claim 29, wherein the network information comprises a response time property of the transmitted data.

33. Apparatus according to claim 29, wherein the network information comprises a throughput of the transmitted data.

34. Apparatus according to claim 29, wherein at least one of the traffic agents multicasts the data.

35. Apparatus according to claim 29, wherein the testing center comprises a memory in which one or more scripts of instructions are stored.

36. Apparatus according to claim 35, wherein the testing center comprises a user interface which enables a user to invoke the scripts.

37. Apparatus according to claim 36, wherein the user interface comprises a graphical user interface which allows a user to create some or all of the scripts.

38. Apparatus according to claim 37, wherein the graphic user interface allows the user to change parameters of the scripts.

39. Apparatus according to claim 29, wherein at least one of the network management agents changes a traffic characteristic of the network responsive to the commands.

40. Apparatus according to claim 39, wherein the at least one of the network management agents alters the operability of a link of the network.

41. Apparatus according to claim 29, wherein the at least one of the network management agents captures the transmitted data.

42. Apparatus according to claim 29, wherein the network management agent comprises a Remote Monitoring agent.

43. Apparat us according to claim 29, wherein the plurality of traffic agents comprise at least one traffic agent which is internal to a node of the network.

44. Apparatus according to claim 29, wherein the plurality of traffic agents comprise at least one traffic agent which is implemented as an integral part of one of the network management agents.