Method and system for transmission control protocol (TCP) retransmit processing

• US 20050135412A1
• Filed: 11/30/2004
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Fan, Kan Frankie
• Granted Patent: US 7,512,144 B2
• Time in Patent Office: Days
• US Class Current: 370/463
• CPC Class Codes: H04L 69/12 Protocol engines
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence

Abstract

Certain aspects of the present invention for transmission control protocol (TCP) retransmission processing may comprise receiving a request for packet retransmission to be processed by an offload network interface card (NIC). A remote peer, a retransmission timer, or a fast retransmission signal may initiate the request. The NIC processes the request information and sends notification to the host of the request. The host searches the TCP buffers of the TCP transmission window in host memory for the packet. Once the packet is located, the host may send the offload NIC the buffer descriptors containing data that locates the packet in host memory. The offload NIC may retrieve the packet from host memory and may retransmit the packet according to the request information. The offload NIC may send notification to the host that the packet has been retransmitted.

Claims

1. A method for packet transmission, the method comprising:

identifying data from a transmission window to be retransmitted by an offload NIC;

acquiring from a host information related to said identified data to be retransmitted; and

retransmitting said identified data based on said acquired information without storing at least a portion of said transmission window onto said offload NIC.

2. The method according to claim 1, further comprising identifying at least a byte of a packet from said transmission window to be retransmitted.

3. The method according to claim 1, further comprising receiving acknowledgement information from at least one remote peer to determine said identified data to be retransmitted.

4. The method according to claim 3, further comprising determining said identified data based on said received acknowledgement information and on a retransmission timer mechanism or a fast retransmit mechanism.

5. The method according to claim 4, further comprising notifying said host of said identified data to be retransmitted.

6. The method according to claim 5, further comprising locating said acquired information related to said identified data to be retransmitted.

7. The method according to claim 6, further comprising transferring to said offload NIC said located acquired information related to said identified data to be retransmitted.

8. The method according to claim 7, further comprising retrieving from said host said identified data to be retransmitted based on said located acquired information related to said identified data.

9. A machine-readable storage having stored thereon, a computer program having at least one code section for packet transmission, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

identifying data from a transmission window to be retransmitted by an offload NIC;

acquiring from a host information related to said identified data to be retransmitted; and

retransmitting said identified data based on said acquired information without storing at least a portion of said transmission window onto said offload NIC.

10. The machine-readable storage according to claim 9, further comprising code for identifying at least a byte of a packet from said transmission window to be retransmitted.

11. The machine-readable storage according to claim 9, further comprising code for receiving acknowledgement information from at least one remote peer to determine said identified data to be retransmitted.

12. The machine-readable storage according to claim 11, further comprising code for determining said identified data based on said received acknowledgement information and on a retransmission timer mechanism or a fast retransmit mechanism.

13. The machine-readable storage according to claim 12, further comprising code for notifying said host of said identified data to be retransmitted.

14. The machine-readable storage according to claim 13, further comprising code for locating said acquired information related to said identified data to be retransmitted.

15. The machine-readable storage according to claim 14, further comprising code for transferring to said offload NIC said located acquired information related to said identified data to be retransmitted.

16. The machine-readable storage according to claim 15, further comprising code for retrieving from said host said identified data to be retransmitted based on said located acquired information related to said identified data.

17. A system for packet transmission, the system comprising:

at least one processor that identifies data from a transmission window to be retransmitted by an offload NIC;

said at least one processor acquires from a host information related to said identified data to be retransmitted; and

said at least one processor retransmits said identified data based on said acquired information without storing at least a portion of said transmission window onto said offload NIC.

18. The system according to claim 17, wherein said at least one processor identifies at least a byte of a packet from said transmission window to be retransmitted.

19. The system according to claim 17, wherein said at least one processor receives acknowledgement information from at least one remote peer to determine said identified data to be retransmitted.

20. The system according to claim 19, wherein said at least one processor determines said identified data based on said received acknowledgement information and on a retransmission timer mechanism or a fast retransmit mechanism.

21. The system according to claim 20, wherein said at least one processor notifies said host of said identified data to be retransmitted.

22. The system according to claim 21, wherein said at least one processor locates said acquired information related to said identified data to be retransmitted.

23. The system according to claim 22, wherein said at least one processor transfers to said offload NIC said located acquired information related to said identified data to be retransmitted.

24. The system according to claim 23, wherein said at least one processor retrieves from said host said identified data to be retransmitted based on said located acquired information related to said identified data.

25. The system according to claim 17, wherein said at least one processor is a portion of said offload NIC.