Method and System for Implementing a Forward Error Correction (FEC) Code for IP Networks for Recovering Packets Lost in Transit

• US 20080285476A1
• Filed: 10/05/2007
• Published: 11/20/2008
• Est. Priority Date: 05/17/2007
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Rajakarunanayake, Yasantha Nirmal
• Application Number:
  US11/868,198
• Publication Number:
  US 20080285476A1
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence

Abstract

Certain aspects of a method and system for implementing a forward error correction (FEC) code for Internet Protocol (IP) networks for recovering data packets lost in transit may be disclosed. At least one forward error correction (FEC) packet comprising a first checksum of at least one selected subset of a plurality of data packets may be received by the client. A second checksum of the selected subset of the plurality of data packets excluding one or more lost data packets may be calculated. One or more lost data packets may be recovered based on comparing the first checksum with the calculated second checksum.

Claims

1. A method for recovering data packets, the method comprising:

receiving at least one forward error correction (FEC) packet comprising a first checksum of at least one selected subset of a plurality of data packets;

calculating a second checksum of said at least one selected subset of said plurality of data packets excluding one or more lost data packets; and

recovering said one or more lost data packets based on comparison between said first checksum with said calculated second checksum.

2. The method according to claim 1, comprising XORing said first checksum with said calculated second checksum to recover said one or more lost data packets.

3. The method according to claim 1, comprising receiving said at least one FEC packet after receiving a particular number of said plurality of data packets.

4. The method according to claim 3, wherein said particular number of said plurality of data packets is equal to 2^N, where N is equal to a number of said one or more lost data packets.

5. The method according to claim 3, comprising modifying said particular number of said plurality of data packets based on a rate of occurrence of said one or more lost data packets.

6. The method according to claim 1, wherein said at least one selected subset of said plurality of data packets is at least equal to (2^N+1−

1)*(2^N), where N is equal to a number of said one or more lost data packets.

7. The method according to claim 1, comprising calculating said first checksum by padding each of said plurality of data packets with one or more zeros when said plurality of data packets comprise variable length data packets.

8. The method according to claim 7, comprising calculating said second checksum by excluding a sequence number field of each of said plurality of data packets if said plurality of data packets comprise variable length data packets.

9. The method according to claim 1, wherein a rate of recovering said one or more lost data packets is proportional to a rate of receiving said at least one FEC packet.

10. The method according to claim 1, comprising recovering said one or more lost data packets based on progressively comparing said first checksum with subsequently calculated second checksums.

11. The method according to claim 1, comprising receiving said plurality of data packets from a server via one or more of:

a wired network connection and a wireless network connection.

12. The method according to claim 1, comprising receiving said plurality of data packets over a multicast network via one or more of:

a DSL network, a cable modem network, Ethernet network and a media over coaxial cable (MoCA) network.

13. A system for recovering data packets, the system comprising:

one or more circuits that enable receipt of at least one forward error correction (FEC) packet comprising a first checksum of at least one selected subset of a plurality of data packets;

said one or more circuits enable calculation of a second checksum of said at least one selected subset of said plurality of data packets excluding one or more lost data packets; and

said one or more circuits enable recovery of said one or more lost data packets based on comparison between said first checksum with said calculated second checksum.

14. The system according to claim 13, wherein said one or more circuits enable XORing of said first checksum with said calculated second checksum to recover said one or more lost data packets.

15. The system according to claim 13, wherein said one or more circuits enable receipt of said at least one FEC packet after receiving a particular number of said plurality of data packets.

16. The system according to claim 15, wherein said particular number of said plurality of data packets is equal to 2^N, where N is equal to a number of said one or more lost data packets.

17. The system according to claim 15, wherein said one or more circuits enable modification of said particular number of said plurality of data packets based on a rate of occurrence of said one or more lost data packets.

18. The system according to claim 13, wherein said at least one selected subset of said plurality of data packets is equal to (2^N+1−

1)*(2^N), where N is equal to a number of said one or more lost data packets.

19. The system according to claim 13, wherein said one or more circuits enable calculation of said first checksum by padding each of said plurality of data packets with one or more zeros, when said plurality of data packets are variable length data packets.

20. The system according to claim 19, wherein said one or more circuits enable calculation of said second checksum by excluding a sequence number field of each of said plurality of data packets, when said plurality of data packets are said variable length data packets.

21. The system according to claim 13, wherein a rate of recovering said one or more lost data packets is proportional to a rate of receiving said at least one FEC packet.

22. The system according to claim 13, wherein said one or more circuits enable recovery of said one or more lost data packets based on progressive comparison of said first checksum with subsequently calculated second checksums.

23. The system according to claim 13, wherein said one or more circuits enable receipt of said plurality of data packets from a server via one or more of:

a wired network connection and a wireless network connection.

24. The system according to claim 13, wherein said one or more circuits enable receipt of said plurality of data packets over a multicast network via one or more of:

a DSL network, a cable modem network, Ethernet network and a media over coaxial cable (MoCA) network.