System and method for identifying upper layer protocol message boundaries

• US 20030172342A1
• Filed: 08/29/2002
• Published: 09/11/2003
• Est. Priority Date: 03/08/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Elzur, Uri
• Granted Patent: US 7,295,555 B2
• Time in Patent Office: Days
• US Class Current: 714/776
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• 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: H04L 69/22 Parsing or analysis of headers

Abstract

Systems and methods that identify the Upper Layer Protocol (ULP) message boundaries are provided. In one example, a method that identifies ULP message boundaries is provided. The method may include one or more of the following steps: attaching a framing header of a frame to a data payload to form a packet, the framing header being placed immediately after the byte stream transport protocol header, the framing header comprising a length field comprising a length of a framing protocol data unit (PDU); and inserting a marker in the packet, the marker pointing backwards to the framing header and being inserted at a preset interval.

Claims

1. A method for identifying ULP messages in a byte stream transport protocol, comprising the steps of:

attaching a framing header of a frame to a data payload to form a packet, the framing header being placed immediately after the byte stream transport protocol header, the framing header comprising a length field comprising a length of a framing PDU; and

inserting a marker in the packet, the marker pointing backwards to the framing header and being inserted at a preset interval.

2. The method according to claim 1, wherein the framing header comprises at least one of control information and data information.

3. The method according to claim 1, wherein the frame comprises a TCP segment.

4. The method according to claim 3, wherein the byte stream transport protocol is fully compliant with internet Engineering Task Force RFCs for TCP and IP communications.

5. The method according to claim 3, wherein the byte stream transport protocol is adapted to provide a solution in which byte stream transport protocol processing occurs before TCP processing is complete and the solution is fully compliant with internet Engineering Task Force RFCs for TCP and IP communications.

6. The method according to claim 1, wherein the frame comprises the framing header with a ULP header.

7. The method according to claim 1, wherein the frame comprises the framing header without a ULP header.

8. The method according to claim 1, wherein the marker comprises a delta value indicating a number of bytes before a marker location to a particular location within the framing header.

9. The method according to claim 1, wherein the marker comprises a delta value indicating a number of bytes before a marker location to a beginning location of the framing header.

10. The method according to claim 1, wherein the marker comprises a delta value indicating a number of bytes immediately after a marker location to a beginning of the framing header.

11. The method according to claim 1, wherein the frame comprises one or more of the markers in every TCP segment

12. The method according to claim 1, wherein the frame header comprises a marker header.

13. The method according to claim 1, further comprising the step of:

attaching a TCP header to the packet to form a TCP frame, the TCP header being disposed immediately before the frame header.

14. The method according to claim 13, further comprising the step of:

transmitting the TCP frame.

15. The method according to claim 14, further comprising the steps of:

receiving the TCP frame;

locating the marker; and

using the marker to locate the framing header.

16. The method according to claim 15, further comprising the steps of:

ascertaining at least one of control information and data information from the framing header or other header located based upon locating a beginning of the framing header; and

performing an operation according to at least one of the control information and the data information.

17. The method according to claim 15, further comprising the steps of:

ascertaining at least one of control information and data information from the framing header or other header located based upon locating a beginning of the framing header; and

making each byte stream transport protocol segment self-descriptive.

18. The method according to claim 17, wherein the step of making comprises adapting each byte stream transport protocol segment such that upper layer data is placed in a pre-designated memory location specific to the upper layer data without requiring any other data, processing or information from other byte stream transport segments.

19. The method according to claim 17, wherein the step of making comprises adapting each byte stream transport protocol segment such that upper layer data is placed in a pre-designated memory location specific to the upper layer data independently of other byte stream transport segments.

20. The method according to claim 19, wherein the upper layer data is placed in the pre-designated memory location specific to the upper layer data even if TCP segments arrive out of order.

21. The method according to claim 17, wherein the step of making comprises adapting each byte stream transport protocol segment such that upper layer data is placed in a pre-designated memory location specific to the upper layer data without any state information being carried from other byte stream transport segments.

22. The method according to claim 16, wherein the step of performing an operation comprises placing the data payload directly into a particular location of a particular memory in accordance with at least one of the control information and the data information.

23. A method for locating a framing header in a received TCP frame, comprising the steps of:

locating a backwards-pointing marker; and

using information stored in the backwards-pointing marker to locate the framing header.

24. The method according to claim 23, wherein the step of locating comprises performing a modulo operation on a TCP sequence number with respect to a preset interval in accordance which the backwards-pointing marker is inserted into a transmitted TCP stream.

25. The method according to claim 23, wherein the step of locating comprises subtracting an initial value and performing a modulo operation on a TCP sequence number with respect to a preset marker interval.

26. The method according to claim 25, wherein the initial value represents a TCP sequence location of a first TCP payload byte.

27. The method according to claim 23, wherein the information stored in the backwards-pointing marker comprises a delta value indicating a number of bytes before a location of the backwards-pointing marker at which the framing header is located.

28. The method according to claim 23, wherein the information stored in the backwards-pointing marker comprises a delta value indicating a number of bytes after a location of the marker at which the framing header is located.

29. The method according to claim 23, wherein the locating of the framing header is deterministic.

30. The method according to claim 23, wherein the marker is protected by at least one of an error detection code and an error correction code carried in a marker field.

31. A method for detecting resegmentation of a TCP segment, comprising the steps of:

(a) locating a backwards-pointing marker in the TCP segment;

(b) determining a location of a framing header using information stored in the backwards-pointing marker; and

(c) determining that resegmentation of the TCP segment has occurred if the framing header is not at the front of the TCP segment after a TCP header of the TCP segment.

32. A method for detecting resegmentation of a TCP segment, comprising the steps of:

(a) locating a backwards-pointing marker in the TCP segment;

(b) determining a location of a framing header using information stored in the backwards-pointing marker; and

(c) determining that resegmentation of the TCP segment has occurred if the backwards-pointing marker points to a location outside of the TCP segment.

33. The method according to claim 32, further comprising the step of:

(d) determining that resegmentation of the TCP segment has occurred if the backwards-pointing marker is not fully present in the TCP segment.

34. A method for detecting resegmentation of a TCP segment, comprising the steps of:

(a) locating a backwards-pointing marker in the TCP segment;

(b) determining a location of a framing header using information stored in the backwards-pointing marker; and

(c) determining that resegmentation of the TCP frame has occurred if a number of payload bytes in the TCP segment is not equal a number indicated by a framing header length field plus a pad and a CRC field.

35. A method for detecting resegmentation of a TCP segment, comprising the steps of:

(a) locating a backwards-pointing marker in the TCP segment;

(b) determining a location of a framing header using information stored in the backwards-pointing marker; and

(c) determining that resegmentation of the TCP frame has occurred if a number of payload bytes in the TCP segment is not equal to a sum of all values of a framing header length fields plus pads and CRC fields for multiple framing PDUs placed in a TCP segment.

36. A method for detecting a potential error in a byte stream transport protocol segment by comparing a received error detection code with a computed error detection code over a framing PDU, comprising the steps of:

(a) if the comparing occurs before byte stream transport protocol processing, then discarding received segment and relying on the byte stream transport recovery protocol without need for specific framing layer recovery;

(b) if the comparing occurs after the byte stream transport protocol processing, then tearing down connection; and

(c) allowing for additional protection beyond the byte stream transport checksum protocol.

37. The method according to claim 36, further comprising the step of:

not accessing any flow specific information.