Method and apparatus for optimizing channel bandwidth utilization by simultaneous reliable transmission of sets of multiple data transfer units (DTUs)

• US 7,330,432 B1
• Filed: 09/09/2002
• Issued: 02/12/2008
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Slutsky, Irina P., Revsin, Vitaly S., Pass, Alexander M.
• Primary Examiner(s): Ngo; Ricky Q.
• Assistant Examiner(s): Hailu; Kibrom T
• Application Number:
  US10/237,944
• Time in Patent Office: 1,982 Days
• Field of Search: 370/235, 370/278, 370/912, 714/18, 714/821
• US Class Current: 370/235
• CPC Class Codes: H04L 1/1685 the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: Y10S 370/912 Packet communications

Abstract

A system and method for reliably transmitting large amounts of data over a high speed network with large latency, such as a communication satellite based network. A transmitting device transmits data transfer units (DTUs) to one or more receiving devices. The transmitting device forms and transmits burst consisting of reliably delivered sets of multiple DTUs. Both the transmitting device and the receiving devices process multiple bursts in parallel, such that subsequent bursts can be transmitted and received prior to the correct receipt of a previously transmitted burst at all of the receiving devices, and/or prior to receipt of a status report at the transmitting device regarding a previously transmitted burst. The transmitting device operates to transmit subsequent bursts even before the receipt of a status information regarding a previous burst, and the receiving devices process subsequently received bursts while awaiting retransmission of a lost or damaged DTU from a previous burst.

Claims

1. A method of transmitting data over a network, comprising:

forming a plurality of data transfer unit bursts, each of said data transfer unit bursts including a plurality of data transfer units;

transmitting said bursts of data transfer units to at least one receiving device;

receiving a plurality of status report messages, each of said status report messages indicating a receipt status with regard to at least one previously transmitted data transfer unit;

recording, responsive to receipt of each of said plurality of status report messages, said receipt status with regard to said at least one previously transmitted data transfer unit;

wherein said transmitting continues in the event at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was not successfully received; and

retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received in response to a predetermined condition being met,

wherein said transmitting said bursts of data transfer units includes, at least at some times, stopping, at least temporarily, transmission of said bursts of data transfer units in response to said predetermined condition being met,

said method further including, in the event at least one status report message was not received indicating a receipt status with regard to at least one of said at least one previously transmitted data transfer unit, transmitting, at least at some times, at least one status request message to request said at least one status report message that was not received, while said transmission of said bursts of data transfer units is stopped, and

wherein said retransmitting said at least one previously transmitted data transfer unit that was not successfully received includes retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received, while said transmission of said bursts of data transfer units is stopped.

2. The method of claim 1, wherein said transmitting continues in the event that said at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was lost.

3. The method of claim 1, wherein said transmitting continues in the event that said at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was damaged.

4. The method of claim 1, wherein a length of each of said data transfer units is less than a maximum data transfer unit length, and wherein said maximum data transfer unit length comprises an integral number of maximum transmission unit lengths with respect to at least a portion of said network.

5. The method of claim 1, wherein said recording said receipt status with regard to said at least one previously transmitted data transfer unit includes incrementing a retransmit counter in the event that said at least one previously transmitted data transfer unit was not successfully received.

6. The method of claim 5, wherein said predetermined condition is met in the event that a value of said retransmit counter equals a burst size, wherein said burst size is a maximum number of data transfer units included in each of said bursts of data transfer units.

7. The method of claim 6, wherein said predetermined condition is met further in the event that transmission is completed for all data transfer units in one of said bursts.

8. The method of claim 1, wherein said retransmitting said at least one previously transmitted data transfer unit that was not successfully received comprises transmitting repair data with regard to said at least one previously transmitted data transfer unit that was not previously received.

9. The method of claim 1, wherein said transmitting said sets of data transfer units further comprises transmitting said bursts of data transfer units to a plurality of receiving devices by including at least one destination address with said sets of data transfer units.

10. The method of claim 9, wherein said at least one destination address is a multicast address.

11. The method of claim 10, wherein said transmitting said bursts of data transfer units further comprises transmitting said bursts of data transfer units over a communication satellite based network.

12. The method of claim 11, wherein said receiving said plurality of status report messages comprises receiving a plurality of status report messages over a back channel interface, wherein said back channel interface operates to receive data from a back channel communications system that is separate from said communication satellite based network.

13. The method of claim 12, wherein said back channel communications system comprises the Internet, and wherein said status report messages comprise a plurality of Internet packets.

14. The method of claim 1, wherein each of said data transfer units comprises at least one Ethernet packet.

15. The method of claim 1, wherein each of said data transfer units comprises at least one Internet Protocol packet.

16. The method of claim 1, wherein each of said data transfer units includes an indication of an associated burst of data transfer units to which said data transfer unit belongs.

17. The method of claim 16, wherein said indication of said associated burst comprises a burst number.

18. The method of claim 16, wherein each of said data transfer units further includes an indication of a position of said data transfer unit within an associated burst.

19. The method of claim 18, wherein each of said data transfer units further includes an indication of a data stream associated with said data transfer unit.

20. A device for transmitting data over a network, said device operable:

to form a plurality of data transfer unit bursts, each of said data transfer unit bursts including a plurality of data transfer units;

to transmit said bursts of data transfer units to at least one receiving device;

to receive a plurality of status report messages, each of said status report messages indicating a receipt status with regard to at least one previously transmitted data transfer unit;

to record, responsive to receipt of each of said plurality of status report messages, said receipt status with regard to said at least one previously transmitted data transfer unit;

wherein said transmitting continues in the event at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was not successfully received; and

to retransmit, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received in response to a predetermined condition being met,

wherein said device is further operable, at least at some times, to stop, at least temporarily, transmission of said bursts of data transfer units in response to said predetermined condition being met,

wherein said device is further operable, in the event at least one status report message was not received indicating a receipt status with regard to at least one of said at least one previously transmitted data transfer unit, to transmit, at least at some times, at least one status request message to request said at least one status report message that was not received, while said transmission of said bursts of data transfer units is stopped, and

wherein said device is further operable to retransmit, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received, while said transmission of said bursts of data transfer units is stopped.

21. The device of claim 20, wherein said device further comprises at least one processor coupled to a program memory.

22. A computer program product, including a computer readable medium, said computer readable medium having a computer program stored thereon, said computer program being executable by at least one processor for transmitting data over a network, said computer program comprising:

program code for forming a plurality of data transfer unit bursts, each of said data transfer unit bursts including a plurality of data transfer units;

program code for transmitting said bursts of data transfer units to at least one receiving device;

program code for receiving a plurality of status report messages, each of said status report messages indicating a receipt status with regard to at least one previously transmitted data transfer unit;

program code for recording, responsive to receipt of each of said plurality of status report messages, said receipt status with regard to said at least one previously transmitted data transfer unit;

wherein said transmitting continues in the event at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was not successfully received; and

program code for retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received in response to a predetermined condition being met,

wherein said program code for transmitting includes program code for, at least at some times, stopping, at least temporarily, transmission of said bursts of data transfer units in response to said predetermined condition being met

said computer program further including program code for, in the event at least one status report message was not received indicating a receipt status with regard to at least one of said at least one previously transmitted data transfer unit, transmitting, at least at some times, at least one status request message to request said at least one status report message that was not received, while said transmission of said bursts of data transfer units is stopped, and

wherein said program code for retransmitting said at least one previously transmitted data transfer unit that was not successfully received includes program code for retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received, while said transmission of said bursts of data transfer units is stopped.

23. A device for transmitting data over a network, comprising:

means for forming a plurality of data transfer unit bursts, each of said data transfer unit bursts including a plurality of data transfer units;

means for transmitting said bursts of data transfer units to at least one receiving device;

means for receiving a plurality of status report messages, each of said status report messages indicating a receipt status with regard to at least one previously transmitted data transfer unit;

means for recording, responsive to receipt of each of said plurality of status report messages, said receipt status with regard to said at least one previously transmitted data transfer unit;

wherein said transmitting continues in the event at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was not successfully received; and

means for retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received in response to a predetermined condition being met,

wherein said means for transmitting is operable, at least at some times, to stop, at least temporarily, transmission of said bursts of data transfer units in response to said predetermined condition being met,

said device further including means for transmitting, at least at some times, in the event at least one status report message was not received indicating a receipt status with regard to at least one of said at least one previously transmitted data transfer unit, at least one status request message to request said at least one status report message that was not received, while said transmission of said bursts of data transfer units is stopped, and

wherein said means for retransmitting is operable to retransmit, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received, while said transmission of said bursts of data transfer units is stopped.

24. A computer data signal embodied in a carrier wave, said computer data signal including a computer program executable by at least one processor for transmitting data over a network, said computer program comprising:

program code for forming a plurality of data transfer unit bursts, each of said data transfer unit bursts including a plurality of data transfer units;

program code for transmitting said bursts of data transfer units to at least one receiving device;

program code for receiving a plurality of status report messages, each of said status report messages indicating a receipt status with regard to at least one previously transmitted data transfer unit;

program code for recording, responsive to receipt of each of said plurality of status report messages, said receipt status with regard to said at least one previously transmitted data transfer unit;

wherein said transmitting continues in the event at least one of said plurality of status report messages indicates that said at least one previously transmitted data transfer unit was not successfully received; and

program code for retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received in response to a predetermined condition being met,

wherein said program code for transmitting includes program code for stopping, at least temporarily, transmission of said bursts of data transfer units in response to said predetermined condition being met,

said computer program further including program code for, in the event at least one status report message was not received indicating a receipt status with regard to at least one of said at least one previously transmitted data transfer unit, transmitting, at least at some times, at least one status request message to request said at least one status report message that was not received, while said transmission of said bursts of data transfer units is stopped, and

wherein said program code for retransmitting said at least one previously transmitted data transfer unit that was not successfully received includes program code for retransmitting, at least at some times, said at least one previously transmitted data transfer unit that was not successfully received, while said transmission of said bursts of data transfer units is stopped.