System, analyzer, and method for synchronizing a distributed system

• US 20020176448A1
• Filed: 06/21/2002
• Published: 11/28/2002
• Est. Priority Date: 12/30/1998
• Status: Active Grant

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Sikdar, Som
• Granted Patent: US 7,120,121 B2
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 43/18 Protocol analysers

Abstract

A method for synchronizing a distributed system is provided. The distributed system includes distributed analyzers. Each analyzer has a synchronization decoder circuit, a medium access controller, and a central processing unit. The distributed system synchronization method comprises receiving multicast information, generating local synchronization signals, receiving control data packets, and beginning processing of monitored data packets. The synchronization decoder circuit receives the multicast information, decodes the multicast information, and responsive to the multicast information, generates local synchronization signals. The decoder synchronization circuit of a first analyzer completes the decoding and the generating in a first time. The first time is adapted to enable the central processing unit of the first analyzer to start and end processing of monitored data packets at a first start time and a first end time. The first start time differs from a start time corresponding to any other analyzer by less than a maximum synchronization time. The first end time differs from an end time corresponding to any other analyzer by less than a maximum synchronization time. The maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed. The medium access controller receives control data packets. Each control data packet corresponds to a data stream. The monitored data packets are transmitted in a data stream selected for monitoring. Responsive to the local synchronization signals and the control data packets, the central processing unit for each analyzer processes monitored data packets.

Claims

1. A method for synchronizing a distributed system, the distributed system having synchronized analyzers, and data streams, the distributed system supporting multicast communications, the method comprising:

selected synchronized analyzers receiving the multicast information and communication packets, each selected synchronized analyzer having processing resources including a synchronization decoder circuit, and one or more packet capture, analysis and generation circuits, the multicast information including destination data corresponding to addresses of the selected synchronized analyzers;

the synchronization decoder circuit decoding the multicast information;

responsive to the multicast information, the synchronization decoder circuit generating local signals; and

the synchronization decoder circuit transferring the local signals to the one or more selected packet capture, analysis and generation circuits.

2. The method of claim 1, wherein the multicast information received by the synchronization decoder circuit.

3. The method of claim 1, wherein:

the data streams comprise transmitted data packets and include monitored data streams selected for analysis at one or more monitored analysis locations; and

the method includes, responsive to the local signals and the communication packets, the selected packet capture, analysis and generation circuits beginning processing of monitored data packets from monitored data streams at a start time.

4. The method of claim 1, wherein:

the multicast information includes synchronization packets and control packets; and

the local signals include synchronization signals and control signals.

5. The method of claim 1, wherein:

the distributed system has analysis locations disposed in the data streams; and

each of the selected packet capture, analysis and generation circuits connected to one or more monitored analysis locations.

6. The method of claim 1, wherein the synchronization decoder circuit of a first selected synchronized analyzer receives the multicast information at a first multicast receipt time (t₁), the selected synchronized analyzers adapted to ensure that the first multicast receipt time differs from the multicast receipt time corresponding to any other selected synchronized analyzer by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

7. The method of claim 1, wherein the synchronized analyzer processing resources include a central processing unit and the method includes:

the central processing unit receiving the communication packets;

responsive to the communication packets, the central processing unit generating commands; and

the central processing unit sending the commands to the packet capture, analysis and generation circuits.

8. The method of claim 1, wherein:

the distributed system includes;

a control unit;

a first network link connecting the control unit to the synchronized analyzers and the synchronized analyzers to each other, the synchronized analyzer includes a medium access controller; and

the method includes;

the control unit transmitting the multicast information through the first network link to the selected synchronized analyzers; and

the control unit transmitting the communications packets through the first network link and the medium access controller to the central processing units of the selected synchronized analyzers.

9. The method of claim 1, wherein the distributed system comprises an Ethernet network including a first network link connecting the synchronized analyzers to the control unit and the synchronized analyzers to each other, the first network link comprises an Ethernet repeater.

10. The method of claim 1, wherein the distributed system comprises an IEEE 802 compliant communications network.

11. The method of claim 1, wherein

the data streams comprise transmitted data packets and include monitored data streams selected for analysis at one or more monitored analysis locations;

and

the synchronized analyzers comprise;

single monitored analysis location synchronized analyzers having one or more packet capture, analysis and generation circuits capturing monitored data packets from a single monitored analysis location; and

multiple monitored analysis location analyzers having a plurality of packet capture, analysis and generation circuits, the plurality of packet capture, analysis and generation circuits capturing monitored data packets from a plurality of monitored analysis locations.

12. The method of claim 1, wherein:

the decoding and generating local signals steps are accomplished in a decoder delay time, the variation of the decoder delay time between selected synchronized analyzers is less than approximately five percent of the decoder delay time; and

the selected packet capture, analysis and generation circuits of a first selected synchronized analyzer start processing the monitored data packets at a first start time, the first start time differs from a start time corresponding to any other selected synchronized analyzer by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

13. The method of claim 1, wherein:

the decoding and generating local signals steps are accomplished in a decoder delay time, the variation of the decoder delay time between selected synchronized analyzers is less than approximately five percent of the decoder delay time; and

the decoder synchronization circuit of a first selected synchronized analyzer transfers the local signals to the selected packet capture, analysis and generation circuits of the first synchronized analyzer at a first transfer time (t₃), the selected synchronized analyzers adapted to ensure that the first transfer time differs from the transfer time corresponding to any other of the selected synchronized analyzers by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

14. The method of claim 2, wherein:

the synchronized analyzer processing resources include;

a medium access controller having a first data link layer address; and

a central processing unit receiving the communications packets through the medium access controller; and

the synchronization decoder circuit has a second data link layer address, the first data link layer address differs from the second data link layer address.

15. The method of claim 3, wherein the method includes:

the selected packet capture, analysis and generating circuits capturing received monitored data packets at a monitored data receipt time;

the selected packet capture, analysis and generating circuits labeling portions of the received monitored data packets with time-stamps to form time-stamped portions, the time-stamps corresponding to the monitored data receipt times; and

the processing of the monitored data packets includes the selected packet capture, analysis and generation circuits;

analyzing the time-stamped portions, the analyzing including generating analysis data; and

storing segments of the time-stamped portions and corresponding analysis data in a memory.

16. The method of claim 3, wherein the processing adapted to analyze and manage the distributed system.

17. The method of claim 3, wherein the method includes, responsive to the multicast information and the communication packets, the packet capture, analysis and generation circuits completing a first process for a first set of monitored data packets, the processing for each selected synchronized analyzer completing at a corresponding end time.

18. The method of claim 6, wherein the method further includes, responsive to the multicast information and the communication packets, the selected packet capture, analysis and generation circuits completing a first process for a first set of monitored data packets, the completing for each selected synchronized analyzer occurring at an end time.

19. The method of claim 8, wherein the control unit comprises a separate control computer.

20. The method of claim 8, wherein the control unit comprises a master analyzer.

21. The method of claim 15, wherein:

the distributed system includes a control unit adapted to transmit the multicast information; and

the method includes the selected packet capture, analysis and generation circuits transmitting analysis information corresponding to the analysis data to the control unit.

22. The method of claim 17, wherein:

the decoding and generating of local signals are accomplished in a decoder delay time, the variation of the decoder delay time between synchronized analyzers is less than approximately five percent of the decoder delay time; and

the selected packet capture, analysis and generation circuits of the first synchronized analyzer completes processing of the monitored data packets at a first end time, the first end time differs from an end time corresponding to any other synchronized analyzer by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

24. The synchronized analyzer of claim 23, including a central processing unit having processing resources adapted to:

receive communication packets from a control unit disposed in the distributed system, and

responsive to the communication packets, generate commands; and

transfer the commands to the packet capture, analysis and generation circuits, the local signals and the commands controlling the processing of the monitored data packets.

25. The synchronized analyzer of claim 23, wherein:

the multicast information includes synchronization packets and control packets; and

the local signals include synchronization signals and control signals.

26. The synchronized analyzer of claim 23, wherein:

the distributed system has analysis locations disposed in the data streams; and

each packet capture, analysis and generation circuit connected to one or more analysis locations.

27. The synchronized analyzer of claim 23, wherein the synchronized analyzer is connected to other synchronized analyzers in the distributed system and a control unit via a first network link.

28. The synchronized analyzer of claim 23, wherein:

the distributed system includes;

a control unit having processing resources adapted to generate and transmit the multicast information; and

a first network link connecting the control unit to the synchronized analyzers, and connecting the synchronized analyzers to each other; and

the synchronization decoder circuit processing resources adapted to receive the multicast information from control unit via the first network link;

29. The synchronized analyzer of claim 23, wherein the distributed system comprises an IEEE 802 compliant communications network.

30. The synchronized analyzer of claim 23, wherein:

the multicast information includes destination data corresponding to addresses of selected synchronized analyzers;

the synchronized analyzer includes;

a medium access controller having a first data link layer address, and

a central processing unit receiving data through the medium access controller;

the synchronization decoder circuit has a second data link layer address, the destination data corresponds to the second data link layer address; and

the first data link layer address differs from the second data link layer address.

31. The synchronized analyzer of claim 23 comprising a single monitored analysis location synchronized analyzer having one or more packet capture, analysis and generation circuits including processing resources adapted to capture monitored data packets from a single monitored analysis location.

32. The synchronized analyzer of claim 23 comprising a multiple monitored analysis location analyzers having a plurality of packet capture, analysis and generation circuits, the plurality of packet capture, analysis and generation circuits having processing resources adapted to capture monitored data packets from a plurality of monitored analysis locations.

33. The synchronized analyzer of claim 23, wherein:

the packet capture, analysis and generation circuits include processing resources adapted to label portions of the received monitored data packets with time-stamps to form time-stamped portions, the time-stamps corresponding to the monitored data receipt times; and

the processing of the monitored data packets includes;

analyzing the time-stamped portions, the analyzing including generating analysis data; and

storing segments of the time-stamped portions and corresponding analysis data in a memory.

34. The synchronized analyzer of claim 23, wherein the packet capture, analysis and generation circuits have processing resources adapted to complete a first process for a first set of monitored data packets at a corresponding end time in response to the multicast information and the communication packets.

35. The synchronized analyzer of claim 23, wherein the decoder synchronization circuit processing resources adapted to decode the multicast information and generate the local signals within a decoder delay time, the variation of the decoder delay time between synchronized analyzers is less than approximately five percent of the decoder delay time.

36. The synchronized analyzer of claim 23, comprising a master analyzer including processing resources adapted to transmit the multicast information to synchronized analyzers connected to the master analyzer.

37. The synchronized analyzer of claim 24, wherein:

the distributed system includes;

a plurality of synchronized analyzers;

a control unit having processing resources adapted to generate and transmit the multicast information; and

a first network link connecting the control unit to the synchronized analyzers, and connecting the synchronized analyzers to each other;

the synchronized analyzer includes a medium access controller; and

the central processing unit processing resources adapted to receive communications packets from the control unit through the first network link and the medium access controller.

38. The synchronized analyzer of claim 33, wherein:

the distributed system includes;

a control unit having processing resources adapted to generate and transmit the multicast information; and

a first network link connecting the control unit to the synchronized analyzers, and connecting the synchronized analyzers to each other; and

the packet capture, analysis and generation circuit processing resources adapted to transmit analysis information corresponding to the analysis data to the control unit.

40. The system of claim 39, wherein:

the multicast information includes synchronization packets and control packets; and

the local signals include synchronization signals and control signals.

41. The system of claim 39, wherein:

the distributed system has analysis locations disposed in the data streams; and

each packet capture, analysis and generation circuit connected to one or more of the analysis locations.

42. The system of claim 39, wherein the synchronized analyzers include a central processing unit having processing resources adapted to:

receive communication packets from the control unit via the first network link;

responsive to the communication packets, generate commands; and

transfer the commands to the packet capture, analysis and generation circuits, the local signals and the commands controlling processing of monitored data packets.

43. The system of claim 39, wherein the distributed system comprises an Ethernet local area network and the first network link comprises an Ethernet repeater.

44. The system of claim 39, wherein the distributed system comprises an IEEE 802 compliant communications network.

45. The system of claim 39, wherein the distributed system comprises a fiber distributed data interface network.

46. The system of claim 39, wherein:

the multicast information includes destination data corresponding to addresses of selected synchronized analyzers;

the synchronized analyzer includes;

a medium access controller having a first data link layer address, and

a central processing unit receiving data through the medium access controller;

the synchronization decoder circuit has a second data link layer address, the destination data corresponds to the second data link layer address; and

the first data link layer address differs from the second data link layer address.

47. The system of claim 39, wherein the synchronized analyzers include single monitored analysis location analyzers, each of the single monitored analysis location analyzers having one or more packet capture, analysis and generation circuits capturing monitored data packets from a single monitored analysis location.

48. The system of claim 39, wherein the synchronized analyzers include multiple monitored analysis location analyzers, each of the multiple monitored analysis location analyzers having a plurality of packet capture, analysis and generation circuits, the plurality of packet capture, analysis and generation circuits capturing monitored data packets from a plurality of monitored analysis locations.

49. The system of claim 39, wherein the packet capture, analysis and generation circuits include processing resources adapted to label portions of the received monitored data packets with time-stamps to form time-stamped portions, the time-stamps corresponding to the monitored data receipt times;

and

the processing of the monitored data packets includes;

analyzing the time-stamped portions, the analyzing including generating analysis data; and

storing segments of the time-stamped portions and corresponding analysis data in a memory.

50. The system of claim 39, wherein the decoder synchronization circuit processing resources adapted to decode the multicast information and generate the local signals steps within a decoder delay time, the variation of the decoder delay time between synchronized analyzers is less than approximately five percent of the decoder delay time.

51. The system of claim 39, wherein the decoder synchronization circuit processing resources of a first synchronized analyzer receive the multicast information at a first multicast receipt time (t₁), the synchronized analyzers adapted to ensure that the first multicast receipt time differs from the multicast receipt time corresponding to any other synchronized analyzer in the distributed system by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

52. The system of claim 39, wherein the packet capture, analysis and generation circuit processing resources of a first synchronized analyzer start processing the monitored data packets at a first start time, the first start time differs from a start time corresponding to any other synchronized analyzer by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

53. The system of claim 39, wherein the decoder synchronization circuit processing resources of a first synchronized analyzer transfer the local signals to selected packet capture, analysis and generation circuits of the first synchronized analyzer at a first transfer time (t₃), the synchronized analyzers adapted to ensure that the first transfer time differs from the transfer time corresponding to any other synchronized analyzer in the distributed system by no more than a maximum synchronization time, the maximum synchronization time comprises a parameter related to a smallest useful packet size and a network speed, and the maximum synchronization time is less than approximately one microsecond.

54. The system of claim 39, wherein one of the synchronized analyzers comprises a master analyzer including processing resources adapted to transmit the multicast information to synchronized analyzers connected to the master analyzer.

55. The system of claim 49, wherein:

the control unit includes processing resources adapted to generate the multicast information; and

the packet capture, analysis and generation circuit processing resources adapted to transmit analysis information corresponding to the analysis data to the control unit.

23. A synchronized analyzer for synchronizing a distributed system comprising:

a synchronization decoder circuit having processing resources adapted to;

receive and decode multicast information;

responsive to the multicast information, generate local signals; and

one or more packet capture, analysis and generation circuits having processing resources adapted to;

receive the local signals at signal receipt times; and

responsive to local signals addressed to one or more selected packet capture, analysis and generation circuits;

capture portions of monitored data packets at monitored data receipt times, the monitored data packets transmitted in monitored data streams, the monitored data streams disposed in the distribution system and selected for analysis; and

process portions of the monitored data packets.

39. A system for synchronizing a distributed system, comprising:

data streams comprising transmitted data packets;

a control unit having processing resources adapted to transmit multicast information;

synchronized analyzers including;

synchronization decoder circuits having processing resources adapted to;

receive and decode the multicast information;

responsive to the multicast information, generate local signals; and

one or more packet capture, analysis and generation circuits having processing resources adapted to;

receive the local signals at signal receipt times; and

responsive to local signals addressed to one or more selected packet capture, analysis and generation circuits;

capture portions of monitored data packets from data streams selected for analysis at monitored data receipt times, and

process the portions of the monitored data packets, the processing of the portions of the monitored data packets adapted to analyze and manage the distributed system; and

a first network link connecting the control unit to the synchronized analyzers and the synchronized analyzers to each other, the control unit processing resources transmit the multicast information to the synchronized analyzers through the first network link.