Reliably transmitting a frame to multiple destinations by embedding sequence numbers in the frame

• US 20030076826A1
• Filed: 10/23/2001
• Published: 04/24/2003
• Est. Priority Date: 10/23/2001
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Verrilli, Colin Beaton, Rao, Sridhar, Gallo, Anthony Matteo, Cosby, David Wayne, Smoak, Frank Andrew, Rovner, Sonia Kiang, Blasiak, Richard John
• Application Number:
  US10/002,476
• Publication Number:
  US 20030076826A1
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments

Abstract

A method, system and computer program product for reliably transmitting a frame. A transmitting node may be coupled to a plurality of destination nodes. The transmitting node may insert in a frame, e.g., multicast frame, to be transmitted to any two or more destination nodes coupled to the transmitting node two or more sequence numbers in the frame to be transmitted. The two or more sequence numbers may be associated with the two or more destination nodes. Upon transmitting the frame, the transmitting node may store a copy of the frame transmitted. Upon verifying that the frame has been delivered to each destination node to receive the frame, the memory associated with the transmitted frame may be released.

Claims

1. A method for reliably transmitting a frame comprising the steps of:

inserting two or more sequence numbers in said frame, wherein each of said two or more sequence numbers is associated with a destination node; and

transmitting said frame to two or more destination nodes.

2. The method as recited in claim 1 further comprising the step of:

inserting one or more bits in a frame header of said frame to select appropriate ports in a switch fabric to transmit said frame.

3. The method as recited in claim 2 further comprising the step of:

setting a bit in said frame header of said frame to indicate an explicit or an implicit acknowledgment.

4. The method as recited in claim 1 further comprising the step of:

saving a copy of said transmitted frame.

5. The method as recited in claim 1 further comprising the step of:

receiving an acknowledgment from a particular destination node of said two or more destination nodes.

6. The method as recited in claim 5 further comprising the steps of:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said particular destination node; and

determining if a sequence number associated with said acknowledgment is greater than an expected sequence number.

7. The method as recited in claim 6, wherein if said sequence number associated with said acknowledgment is greater than said expected sequence number then the method further comprises the step of:

detecting a lost acknowledgment.

8. The method as recited in claim 5 further comprising the steps of:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said particular destination node;

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received; and

identifying a previous entry associated with a frame transmitted with an implicit acknowledgment in said data structure associated with said particular destination node as having been received.

9. The method as recited in claim 5 further comprising the steps of:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said frame associated with said acknowledgment; and

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received.

10. The method as recited in claim 9 further comprising the step of:

determining if there are outstanding responses for said frame associated with said acknowledgment.

11. The method as recited in claim 10, wherein if there are outstanding responses for said frame associated with said acknowledgment then the method further comprises the step of:

waiting to receive an additional acknowledgment.

12. The method as recited in claim 10, wherein if there are no outstanding responses for said frame then the method further comprises the step of:

releasing memory associated with said frame associated with said acknowledgment.

13. The method as recited in claim 1 further comprising the step of:

receiving a request to retransmit said frame from a particular destination node of said two or more destination nodes; and

retransmitting said frame to said particular destination node of said two or more destination nodes.

14. The method as recited in claim 1, wherein said frame is a multicast frame.

15. A computer program product embodied in a machine readable medium for reliably transmitting a frame, comprising:

programming operable for inserting two or more sequence numbers in said frame, wherein each of said two or more sequence numbers is associated with a destination node; and

programming operable for transmitting said frame to two or more destination nodes.

16. The computer program product as recited in claim 15 further comprises:

programming operable for inserting one or more bits in a frame header of said frame to select appropriate ports in a switch fabric to transmit said frame.

17. The computer program product as recited in claim 16 further comprises:

programming operable for setting a bit in said frame header of said frame to indicate an explicit or an implicit acknowledgment.

18. The computer program product as recited in claim 15 further comprises:

programming operable for saving a copy of said transmitted frame.

19. The computer program product as recited in claim 15 further comprises:

programming operable for receiving an acknowledgment from a particular destination node of said two or more destination nodes.

20. The computer program product as recited in claim 19 further comprises:

programming operable for identifying said particular destination node;

programming operable for identifying a frame associated with said acknowledgment;

programming operable for reading a data structure associated with said particular destination node; and

programming operable for determining if a sequence number associated with said acknowledgment is greater than an expected sequence number.

21. The computer program product as recited in claim 20, wherein if said sequence number associated with said acknowledgment is greater than said expected sequence number then the computer program product further comprises:

programming operable for detecting a lost acknowledgment.

22. The computer program product as recited in claim 19 further comprises:

programming operable for identifying a frame associated with said acknowledgment;

programming operable for reading a data structure associated with said particular destination node;

programming operable for indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received; and

programming operable for identifying a previous entry associated with a frame transmitted with an implicit acknowledgment in said data structure associated with said particular destination node as having been received.

23. The computer program product as recited in claim 19 further comprises:

programming operable for identifying said particular destination node;

programming operable for identifying a frame associated with said acknowledgment;

programming operable for reading a data structure associated with said frame associated with said acknowledgment; and

programming operable for indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received.

24. The computer program product as recited in claim 23 further comprises:

programming operable for determining if there are outstanding responses for said frame associated with said acknowledgment.

25. The computer program product as recited in claim 24, wherein if there are outstanding responses for said frame associated with said acknowledgment then the computer program product further comprises:

programming operable for waiting to receive an additional acknowledgment.

26. The computer program product as recited in claim 24, wherein if there are no outstanding responses for said frame then the computer program product further comprises:

programming operable for releasing memory associated with said frame associated with said acknowledgment.

27. The computer program product as recited in claim 15 further comprises:

programming operable for receiving a request to retransmit said frame from a particular destination node of said two or more destination nodes; and

programming operable for retransmitting said frame to said particular destination node of said two or more destination nodes.

28. The computer program product as recited in claim 15, wherein said frame is a multicast frame.

29. A node, comprising:

a processor; and

a memory unit coupled to said processor, wherein said memory unit is operable for storing a computer program operable for reliably transmitting a frame, wherein the computer program is operable for performing the following programming steps;

inserting two or more sequence numbers in said frame, wherein each of said two or more sequence numbers is associated with a destination node; and

transmitting said frame to two or more destination nodes.

30. The node as recited in claim 29, wherein the computer program is further operable for performing the following programming step:

inserting one or more bits in a frame header of said frame to select appropriate ports in a switch fabric to transmit said frame.

31. The node as recited in claim 30, wherein the computer program is further operable for performing the following programming step:

setting a bit in said frame header of said frame to indicate an explicit or an implicit acknowledgment.

32. The node as recited in claim 29, wherein the computer program is further operable for performing the following programming step:

saving a copy of said transmitted frame.

33. The node as recited in claim 29, wherein the computer program is further operable for performing the following programming step:

receiving an acknowledgment from a particular destination node of said two or more destination nodes.

34. The node as recited in claim 33, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said particular destination node; and

determining if a sequence number associated with said acknowledgment is greater than an expected sequence number.

35. The node as recited in claim 34, wherein if said sequence number associated with said acknowledgment is greater than said expected sequence number then the computer program is further operable for performing the following programming step:

detecting a lost acknowledgment.

36. The node as recited in claim 33, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said particular destination node;

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received; and

identifying a previous entry associated with a frame transmitted with an implicit acknowledgment in said data structure associated with said particular destination node as having been received.

37. The node as recited in claim 33, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said frame associated with said acknowledgment; and

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received.

38. The node as recited in claim 37, wherein the computer program is further operable for performing the following programming step:

determining if there are outstanding responses for said frame associated with said acknowledgment.

39. The node as recited in claim 38, wherein if there are outstanding responses for said frame associated with said acknowledgment then the computer program is further operable for performing the following programming step:

waiting to receive an additional acknowledgment.

40. The node as recited in claim 38, wherein if there are no outstanding responses for said frame then the computer program is further operable for performing the following programming step:

releasing memory associated with said frame associated with said acknowledgment.

41. The node as recited in claim 29, wherein the computer program is further operable for performing the following programming steps:

receiving a request to retransmit said frame from a particular destination node of said two or more destination nodes; and

retransmitting said frame to said particular destination node of said two or more destination nodes.

42. The node as recited in claim 29, wherein said frame is a multicast frame.

43. A system, comprising:

a transmitting node configured to transmit one or more frames of data;

a switch fabric coupled to said transmitting node configured to direct said transmitted one or more frames of data;

a plurality of destination nodes coupled to said switch fabric, wherein each of said plurality of destination nodes is configured to receive one or more of said one or more frames of data; and

wherein said transmitting node comprises;

a processor; and

a memory unit coupled to said processor, wherein said memory unit is operable for storing a computer program operable for reliably transmitting one or more frames of data, wherein the computer program is operable for performing the following programming steps;

inserting two or more sequence numbers in a frame of data, wherein each of said two or more sequence numbers is associated with one of said plurality of destination nodes; and

transmitting said frame of data to two or more of said plurality of destination nodes.

44. The system as recited in claim 43, wherein the computer program is further operable for performing the following programming step:

inserting one or more bits in a frame header of said frame of data to select appropriate ports in said switch fabric to transmit said frame of data.

45. The system as recited in claim 44, wherein the computer program is further operable for performing the following programming step:

setting a bit in said frame header of said frame of data to indicate an explicit or an implicit acknowledgment.

46. The system as recited in claim 43, wherein the computer program is further operable for performing the following programming step:

saving a copy of said transmitted frame of data.

47. The system as recited in claim 43, wherein the computer program is further operable for performing the following programming step:

receiving an acknowledgment from a particular destination node of said two or more destination nodes.

48. The system as recited in claim 47, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame of data associated with said acknowledgment;

reading a data structure associated with said particular destination node; and

determining if a sequence number associated with said acknowledgment is greater than an expected sequence number.

49. The system as recited in claim 48, wherein if said sequence number associated with said acknowledgment is greater than said expected sequence number then the computer program is further operable for performing the following programming step:

detecting a lost acknowledgment.

50. The system as recited in claim 47, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame associated with said acknowledgment;

reading a data structure associated with said particular destination node;

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received; and

identifying a previous entry associated with a frame transmitted with an implicit acknowledgment in said data structure associated with said particular destination node as having been received.

51. The system as recited in claim 47, wherein the computer program is further operable for performing the following programming steps:

identifying said particular destination node;

identifying a frame of data associated with said acknowledgment;

reading a data structure associated with said frame of data associated with said acknowledgment; and

indicating in an entry in said data structure associated with said particular destination node that a frame associated with said acknowledgment from said particular destination node has been received.

52. The system as recited in claim 51, wherein the computer program is further operable for performing the following programming step:

determining if there are outstanding responses for said frame of data associated with said acknowledgment.

53. The system as recited in claim 52, wherein if there are outstanding responses for said frame associated with said acknowledgment then the computer program is further operable for performing the following programming step:

waiting to receive an additional acknowledgment.

54. The system as recited in claim 52, wherein if there are no outstanding responses for said frame then the computer program is further operable for performing the following programming step:

releasing memory associated with said frame of data associated with said acknowledgment.