System, device, and method for detecting and recovering from failures in a multicast communication system

• US 20010037472A1
• Filed: 12/14/2000
• Published: 11/01/2001
• Est. Priority Date: 05/02/2000
• Status: Active Grant

• Current Assignee: Avaya Incorporated
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Li, Yunzhou
• Granted Patent: US 6,751,747 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A system, device, and method for detecting and recovering from failures in a multicast communication system involves joining a multicast group over a primary interface, monitoring for multicast group information received over the primary interface, and determining that there is a multicast group failure if no multicast group information is received over the primary interface for a predetermined amount of time. Recovering from such a failure typically involves joining the multicast group over a backup interface in order to continue receiving multicast group information over the backup interface. A relay/proxy device may join the multicast group on behalf of a multicast host and forward multicast group information to the multicast host.

Claims

1. A method for detecting a failure in a multicast communication network, the method comprising:

joining a multicast group over a primary interface; and

determining that no multicast group information is received over the primary interface for a predetermined amount of time.

2. The method of

claim 1

, wherein joining the multicast group over the primary interface comprises:

receiving a request for multicast group membership information over the primary interface; and

sending a response to the request for multicast group membership information over the primary interface, the response indicating membership in the multicast group.

3. The method of

claim 2

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

4. The method of

claim 1

, wherein the predetermined amount of time is 16 seconds.

5. The method of

claim 1

, wherein determining that no multicast group information is received over the primary interface for a predetermined amount of time comprises:

monitoring for multicast group information received over the primary interface.

6. The method of

claim 1

, wherein determining that no multicast group information is received over the primary interface for a predetermined amount of time comprises:

maintaining for the multicast group a timer that expires when no multicast group information is received over the primary interface for the predetermined amount of time; and

determining that the timer expired.

7. The method of

claim 6

, wherein maintaining the timer comprises:

resetting the timer when multicast group information is received over the primary interface.

8. The method of

claim 6

, wherein the timer is one of:

a count-up timer; and

a count-down timer.

9. The method of

claim 1

, further comprising:

recovering from the failure.

10. The method of

claim 9

, wherein recovering from the failure comprises:

joining the multicast group over a backup interface.

11. The method of

claim 10

, wherein joining the multicast group over the backup interface comprises:

receiving a request for multicast group membership information over the backup interface; and

sending a response to the request for multicast group membership information over the backup interface, the response indicating membership in the multicast group.

12. The method of

claim 11

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

13. The method of

claim 10

, further comprising:

remaining joined to the multicast group over the primary interface after joining the multicast group over the backup interface;

determining that multicast group information is being received over the primary interface; and

leaving the multicast group over the backup interface.

14. The method of

claim 13

, wherein remaining joined to the multicast group over the primary interface after joining the multicast group over the backup interface comprises:

receiving a request for multicast group membership information over the primary interface; and

sending a response to the request for multicast group membership information over the primary interface, the response indicating membership in the multicast group.

15. The method of

claim 13

, wherein determining that multicast group information is being received over the primary interface comprises:

monitoring for multicast group information received over the primary interface.

16. The method of

claim 13

, wherein leaving the multicast group over the backup interface comprises:

receiving a request for multicast group membership information over the backup interface; and

sending a response to the request for multicast group membership information over the backup interface, the response without an indication of membership in the multicast group.

17. The method of

claim 16

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

18. The method of

claim 1

, wherein joining the multicast group over the primary interface comprises:

joining the multicast group over the primary interface on behalf of a multicast host.

19. The method of

claim 18

, wherein joining the multicast group over the primary interface on behalf of a multicast host comprises:

sending a request for multicast group membership information to the multicast host over a host interface; and

receiving a response to the request for multicast group membership information from the multicast host over the host interface, the response indicating membership in the multicast group.

20. The method of

claim 19

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

21. An apparatus for detecting a failure in a multicast communication network, the apparatus comprising:

a primary interface for coupling to a first multicast network; and

proxy logic operably coupled to join a multicast group over the primary interface and determine that no multicast group information is received over the primary interface for a predetermined amount of time.

22. The apparatus of

claim 21

, wherein the proxy logic is operably coupled to receive a request for multicast group membership information over the primary interface and send a response to the request for multicast group membership information over the primary interface indicating membership in the multicast group in order to join the multicast group over the primary interface.

23. The apparatus of

claim 22

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

24. The apparatus of

claim 21

, wherein the predetermined amount of time is 16 seconds.

25. The apparatus of

claim 21

, wherein the proxy logic is operably coupled to monitor for multicast group information received over the primary interface in order to determine that no multicast group information is received over the primary interface for a predetermined amount of time

26. The apparatus of

claim 21

, wherein the proxy logic is operably coupled to maintain for the multicast group a timer that expires when no multicast group information is received over the primary interface for the predetermined amount of time and determine that the timer expired in order to determine that no multicast group information is received over the primary interface for a predetermined amount of time.

27. The apparatus of

claim 26

, wherein the proxy logic is operably coupled to reset the timer when multicast group information is received over the primary interface.

28. The apparatus of

claim 26

, wherein the timer is one of:

a count-up timer; and

a count-down timer.

29. The apparatus of

claim 21

, wherein the proxy logic is operably coupled to recover from the failure.

30. The apparatus of

claim 29

, further comprising a backup interface, wherein the proxy logic is operably coupled to join the multicast group over the backup interface in order to recover from the failure.

31. The apparatus of

claim 30

, wherein the proxy logic is operably coupled to receive a request for multicast group membership information over the backup interface and send a response to the request for multicast group membership information over the backup interface indicating membership in the multicast group in order to join the multicast group over the backup interface.

32. The apparatus of

claim 31

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

33. The apparatus of

claim 30

, wherein the proxy logic is operably coupled to remain joined to the multicast group over the primary interface after joining the multicast group over the backup interface and leave the multicast group over the backup interface upon determining that multicast group information is being received over the primary interface.

34. The apparatus of

claim 33

, wherein the proxy logic is operably coupled to receive a request for multicast group membership information over the primary interface and send a response to the request for multicast group membership information over the primary interface indicating membership in the multicast group in order to remain joined to the multicast group over the primary interface after joining the multicast group over the backup interface.

35. The apparatus of

claim 33

, wherein the proxy logic is operably coupled to monitor for multicast group information received over the primary interface in order to determine that multicast group information is being received over the primary interface.

36. The apparatus of

claim 33

, wherein the proxy logic is operably coupled to receive a request for multicast group membership information over the backup interface and send a response to the request for multicast group membership information over the backup interface without an indication of membership in the multicast group in order to leave the multicast group over the backup interface.

37. The apparatus of

claim 36

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

38. The apparatus of

claim 21

, wherein the proxy logic is operably coupled to join the multicast group over the primary interface on behalf of a multicast host.

39. The apparatus of

claim 38

, further comprising a host interface, wherein the proxy logic is operably coupled to send a request for multicast group membership information to the multicast host over the host interface and receive a response to the request for multicast group membership information from the multicast host over the host interface indicating membership in the multicast group in order to join the multicast group over the primary interface on behalf of a multicast host.

40. The apparatus of

claim 39

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

41. A computer program for controlling a computer system to detect a failure in a multicast communication network, the computer program comprising:

proxy logic programmed to join a multicast group over a primary interface and determine that no multicast group information is received over the primary interface for a predetermined amount of time.

42. The computer program of

claim 41

, wherein the proxy logic is programmed to receive a request for multicast group membership information over the primary interface and send a response to the request for multicast group membership information over the primary interface indicating membership in the multicast group in order to join the multicast group over the primary interface.

43. The computer program of

claim 42

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

44. The computer program of

claim 41

, wherein the predetermined amount of time is 16 seconds.

45. The computer program of

claim 41

, wherein the proxy logic is programmed to monitor for multicast group information received over the primary interface in order to determine that no multicast group information is received over the primary interface for a predetermined amount of time

46. The computer program of

claim 41

, wherein the proxy logic is programmed to maintain for the multicast group a timer that expires when no multicast group information is received over the primary interface for the predetermined amount of time and determine that the timer expired in order to determine that no multicast group information is received over the primary interface for a predetermined amount of time.

47. The computer program of

claim 46

, wherein the proxy logic is programmed to reset the timer when multicast group information is received over the primary interface.

48. The computer program of

claim 46

, wherein the timer is one of:

a count-up timer; and

a count-down timer.

49. The computer program of

claim 41

, wherein the proxy logic is programmed to recover from the failure.

50. The computer program of

claim 49

, wherein the proxy logic is programmed to join the multicast group over a backup interface in order to recover from the failure.

51. The computer program of

claim 50

, wherein the proxy logic is programmed to receive a request for multicast group membership information over the backup interface and send a response to the request for multicast group membership information over the backup interface indicating membership in the multicast group in order to join the multicast group over the backup interface.

52. The computer program of

claim 51

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

53. The computer program of

claim 50

, wherein the proxy logic is programmed to remain joined to the multicast group over the primary interface after joining the multicast group over the backup interface and leave the multicast group over the backup interface upon determining that multicast group information is being received over the primary interface.

54. The computer program of

claim 53

, wherein the proxy logic is programmed to receive a request for multicast group membership information over the primary interface and send a response to the request for multicast group membership information over the primary interface indicating membership in the multicast group in order to remain joined to the multicast group over the primary interface after joining the multicast group over the backup interface.

55. The computer program of

claim 53

, wherein the proxy logic is programmed to monitor for multicast group information received over the primary interface in order to determine that multicast group information is being received over the primary interface.

56. The computer program of

claim 53

, wherein the proxy logic is programmed to receive a request for multicast group membership information over the backup interface and send a response to the request for multicast group membership information over the backup interface without an indication of membership in the multicast group in order to leave the multicast group over the backup interface.

57. The computer program of

claim 56

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

58. The computer program of

claim 41

, wherein the proxy logic is programmed to join the multicast group over the primary interface on behalf of a multicast host.

59. The computer program of

claim 58

, wherein the proxy logic is programmed to send a request for multicast group membership information to the multicast host over a host interface and receive a response to the request for multicast group membership information from the multicast host over the host interface indicating membership in the multicast group in order to join the multicast group over the primary interface on behalf of a multicast host.

60. The computer program of

claim 59

, wherein the request for multicast group membership information comprises an IGMP query message, and wherein the response to the request for multicast group membership information comprises an IGMP report message.

61. A multicast communication system comprising a networking device coupled to a multicast communication network through a primary interface, wherein the multicast communication network supports a multicast group, and wherein the networking device joins the multicast group over the primary interface and determines that the multicast group failed over the primary interface if no multicast group information is received over the primary interface for a predetermined amount of time.

62. The multicast communication system of

claim 61

, wherein the networking device is additionally coupled to the multicast communication network through a backup interface, and wherein the networking device joins the multicast group over the backup interface upon determining that the multicast group failed over the primary interface.

63. The multicast communication system of

claim 62

, wherein the networking device continues monitoring for multicast group information received over the primary interface after joining the multicast group over the backup interface and leaves the multicast group over the backup interface if multicast group information is received over the primary interface.

64. The multicast communication system of

claim 61

, further comprising a multicast host coupled to the networking device over a host interface, wherein the networking device joins the multicast group on behalf of the multicast host.