Method and system for handling out-of-order segments in a wireless system via direct data placement

• US 20060007935A1
• Filed: 05/11/2005
• Published: 01/12/2006
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Bennett, James D., Karaoguz, Jeyhan, Fischer, Matthew, ElZur, Uri
• Granted Patent: US 7,826,457 B2
• Time in Patent Office: Days
• US Class Current: 370/395.500
• CPC Class Codes: H04L 1/1841 Resequencing
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9094 Arrangements for simultaneous transmit and receive, e.g. simultaneous reading/writing from/to the storage element
• 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 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/06 Transport layer protocols, e.g. TCP [Transport Control Protocol] over wireless transmission control protocol/Internet protocol [TCP/IP] or user datagram protocol [UDP] H04L69/16

Abstract

A method and system for handling or processing out-of-order TCP segments in a wireless system may comprise at least one of: placing a first TCP segment received by a wireless network processor in a host buffer and having a mapping between a TCP sequence number and a corresponding buffer address. It may be determined whether a second TCP segment received by the wireless network processor is one of an in-order TCP segment or an out-of-order TCP segment. If the second received TCP segment is an out-of-order TCP segment, then control information associated with at least the second TCP segment may be stored locally on the wireless network processor. The out-of-order TCP segment may be placed in a portion of the host buffer.

Claims

1. A method for handling out-of-order TCP segments in a wireless system, the method comprising:

at least one of;

placing a first TCP segment received by a wireless network processor in a host buffer and mapping a TCP sequence number of said first TCP segment and a corresponding buffer address, and determining whether a second received TCP segment is one of an in-order TCP segment or an out-of-order TCP segment; and

if said second TCP segment received by said wireless network processor is an out-of-order TCP segment;

storing control information associated with at least said second TCP segment locally on said wireless network processor; and

placing said out-of-order TCP segment in a portion of said host buffer.

2. The method according to claim 1, further comprising recording at least a buffer address occupied by an end of said first received TCP segment on said wireless network processor, said buffer being one of a TCP buffer, ULP buffer and an application buffer.

3. The method according to claim 2, further comprising if said second received TCP segment is an in-order TCP segment, placing said in-order TCP segment adjacent to said first received TCP segment in said host buffer.

4. The method according to claim 3, further comprising placing said in-order TCP segment starting from an address adjacent to said recorded address occupied by said end of said first received TCP segment in said host buffer.

5. The method according to claim 4, further comprising at least one of:

recording by said wireless network processor, at least one of data indicating;

an end buffer address occupied by an end of said in-order TCP segment;

a start buffer address plus a length of a data portion of said in-order TCP segment; and

a buffer address of a byte following an end of said in-order TCP segment; and

storing on said wireless network processor, control information associated with at least one of said indicating data.

6. The method according to claim 1, further comprising at least one of:

recording on said wireless network processor,

at least one of data indicating;

an address occupied by a start of said placed out-of-order TCP segment and an address occupied by an end of said placed out-of-order TCP segment; and

a start buffer address of said plus a length occupied by said placed out-of-order TCP segment;

storing on said wireless network processor, control information associated with said indicating data on said wireless network processor.

7. The method according to claim 6, further comprising receiving a third out-of-order TCP segment by said wireless network processor.

8. The method according to claim 7, further comprising determining placement in said host buffer of said third received out-of-order TCP segment by said wireless network processor.

9. The method according to claim 7, further comprising:

if said third received out-of-order TCP segment is in-order with said placed out-of-order TCP segment;

placing said third out-of-order TCP segment adjacent to said placed out-of-order TCP segment in said host buffer; and

at least one of;

adjusting said start address occupied by said placed out-of-order TCP segment to become a start address of a combined said third out-of-order TCP segment and said out-of-order TCP segment; and

adjusting said end address occupied by said placed out-of-order TCP segment to become an end address of said combined said third out-of-order TCP segment and said out-of-order TCP segment.

10. The method according to claim 7, further comprising if said third received out-of-order TCP segment is out-of-order with respect to said placed out-of-order TCP segment, placing said third out-of-order TCP segment at an address in said host buffer that is one of located before said placed out-of-order TCP segment and located after said placed out-of-order TCP segment.

11. The method according to claim 10, further comprising at least one of:

recording on said wireless network processor, at least one of location data representing;

a start address and an end address of a location where said third received TCP segment is placed in said host buffer on said wireless network processor;

a start address plus a length of where said third received TCP segment is placed in said host buffer on said wireless network processor; and

a byte following an end of where said third received TCP segment is placed in said host buffer on said wireless network processor; and

storing on said wireless network processor, control information associated with at least said location data of where said third received TCP segment is placed.

12. The method according to claim 1, further comprising adjusting a TCP window to an end of said last in order received TCP segment upon said placing of said first received TCP segment in said host buffer.

13. The method according to claim 12, further comprising one of:

adjusting said left edge of said TCP window to a next byte immediately following an end of an out-of-order TCP segment placed adjacent to an end of a last in-order previously received TCP segment; and

adjusting said left edge of said TCP window to a next byte immediately following an end of a last of a plurality of out-of-order TCP segments placed adjacent to an end of a last in-order previously received TCP segment.

14. The method according to claim 12, further comprising adjusting said left edge of TCP window to the next byte immediately following an end of a last in-order TCP segment placed adjacent to said first received TCP segment.

15. The method according to claim 14, further comprising storing control information associated with at least a location of said TCP window on said wireless network processor.

16. The method according to claim 15, further comprising updating said stored control information associated with at least a location of said TCP window whenever said TCP window is adjusted.

17. The method according to claim 1, further comprising:

computing a buffer address in a first buffer for a location of a first byte of data for a first TCP segment;

computing a buffer address for said first data byte in a second TCP segment based on a buffer address that corresponds to a TCP segment number of said second TCP segment; and

computing an offset from the said TCP segment number that corresponds to said first TCP segment to a first byte of said second TCP segment.

18. The method according to claim 17, further comprising determining whether said computed offset is larger than a length of said first buffer.

19. The method according to claim 18, further comprising if said computed offset is larger than said length of said first buffer, subtracting said length of said first buffer from said computed offset resulting in a new offset.

20. The method according to claim 19, further comprising subtracting a length of a second buffer from said new offset.

21. The method according to claim 20, further comprising if said subtracting of said second buffer results in said new offset being less than a length of said second buffer, buffering data for said second TCP segment in said first buffer and said second buffer.

22. The method according to claim 21, further comprising if said new offset is greater than a length of said second buffer, subtracting a length of other buffers until one of:

said buffers are exhausted; and

a remaining offset is less than a length of a current buffer.

23. The method according to claim 22, further comprising if a remaining offset is less than a length of said current buffer, buffering data for said second TCP segment in said second buffer, said third buffer, and said other buffers.

24. The method according to claim 22, further comprising if said buffers are exhausted, dropping said second TCP segment.

27. The system according to claim 24, wherein said at least one processor places said in-order TCP segment adjacent to said first received TCP segment in said host buffer if said second received TCP segment is an in-order TCP segment.

28. The system according to claim 27, wherein said at least one processor places said in-order TCP segment starting from an address adjacent to said recorded address occupied by said end of said first received TCP segment in said host buffer.

29. The system according to claim 28, wherein said at least one processor at least one of:

records by said wireless network processor, at least one of data indicating;

an end buffer address occupied by an end of said in-order TCP segment;

a start buffer address plus a length of a data portion of said in-order TCP segment; and

a buffer address of a byte following an end of said in-order TCP segment; and

stores on said wireless network processor, control information associated with at least one of said indicating.

30. The system according to claim 24, wherein said at least one processor at least one of:

records on said wireless network processor,

at least one of data indicating;

an address occupied by a start of said placed out-of-order TCP segment and an address occupied by an end of said placed out-of-order TCP segment; and

a start buffer address of said plus a length occupied by said placed out-of-order TCP segment; and

stores on said wireless network processor, control information associated with said indicating data on said wireless network processor.

25. A system for handling out-of-order TCP segments in a wireless, the system comprising:

at least one processor for at least one of;

placing a first TCP segment received by a wireless network processor in a host buffer and having a mapping between a TCP sequence number and a corresponding buffer address, and determining whether a second TCP segment received by said wireless network processor is one of an in-order TCP segment or an out-of-order TCP segment; and

if said second received TCP segment is an out-of-order TCP segment;

said at least one processor stores control information associated with at least said second TCP segment locally on said wireless network processor; and

said at least one processor places said out-of-order TCP segment in a portion of said host buffer.

26. The system according to claim 25, wherein said at least one processor records at least a buffer address occupied by an end of said first received TCP segment on said wireless network processor, said buffer being one of a TCP buffer, ULP buffer and an application buffer.

31. The system according to claim 25, wherein said buffer address is provided by at least one of:

TCP, ULP, and a driver.

32. The system according to claim 25, wherein said at least one processor is one of a TCP offload engine (TOE), a RISC processor and a finite state machine (FSM), each of which is integrated within said wireless network processor.