Apparatus and method for scaling TCP off load buffer requirements by segment size

• US 20030084185A1
• Filed: 10/30/2001
• Published: 05/01/2003
• Est. Priority Date: 10/30/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Pinkerton, Jim
• Granted Patent: US 7,124,198 B2
• Time in Patent Office: Days
• US Class Current: 709/236
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/561 Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 69/06 Notations for structuring of protocol data, e.g. abstract syntax notation one [ASN.1]
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method and apparatus to ensure that protocol data units received out of order do not have to be buffered by a reassembly buffer in the performance path is presented. When an application or device requests to transfer data with another application or device, a framing protocol sends one or more complete protocol data units preceded by a framing header that is aligned with the transport header. The framing header contains information that allows the receiving application or device to determine where the protocol data unit should be placed so that successive protocol data units can be recovered when a previous protocol data unit has been received out of order.

Claims

1. A method to transform a non self-describing segment of a transport protocol into a self-describing segment for an upper layer protocol, the method comprising the steps of:

aligning a framing header with the non self-describing segment; and

putting segment description information in the framing header.

2. The method of claim 1 further comprising the step of limiting an upper layer protocol data unit size to the smaller of a maximum transport segment size and a size that will fit within the non self-describing segment.

3. The method of claim 2 wherein the non self-describing segment is being sent on a connection to a destination address, the method including the step of terminating the connection if the upper layer protocol data unit is greater than the smaller of a maximum transport segment size and the size that will fit within the non self-describing segment.

4. The method of claim 1 further comprising the step of putting a destination buffer id and offset in the non self-describing segment.

5. The method of claim 1 further comprising the step of putting a destination buffer id and a destination address in the non self-describing segment.

6. A computer-readable medium having computer executable instructions for performing steps to transform a non self-describing segment of a transport protocol to a self-describing segment for an upper layer protocol, the steps comprising:

obtaining segment description information; and

putting the segment description information in one of a header aligned with a header of the non self-describing segment and the header of the non self-describing segment.

7. The computer-readable medium of claim 6 wherein the segment description information includes a data size of data in the non self-describing segment, the computer-readable medium having further computer-executable instructions for performing the step of generating an error message if the data size exceeds the smaller of a maximum transport segment size and a size that will fit within the non self-describing segment.

8. The computer-readable medium of claim 6 having further computer-executable instructions for performing the step of putting zero-copy information in the non self-describing segment.

9. The computer-readable medium of claim 6 having further computer-executable instructions for performing the step of putting a destination buffer id and a destination address in the non self-describing segment.

10. The computer-readable medium of claim 6 having further computer-executable instructions for performing the step of putting a destination buffer id and a data size and offset in the non self-describing segment.

11. A method to transform a non self-describing segment of a transport protocol to a self-describing segment for an upper layer protocol comprising the steps of:

obtaining segment description information;

putting the segment description information in a header aligned with a header of the non-self describing segment or the header of the non self-describing segment.

12. The method of claim 11 wherein the segment description information includes a data size of data in the non self-describing segment, the method including the step of fragmenting the data into self-describing segments if the data size exceeds the smaller of a maximum transport segment size and a size that will fit within the non-self describing segment.

13. The method of claim 11 further comprising the step of putting zero-copy information in the non self-describing segment.

14. The method of claim 11 wherein the step of putting segment description information in the header includes the step of putting a destination buffer id and a destination address in the header.

15. The method of claim 11 wherein the step of putting segment description information in the header includes the step of putting the data size and an offset in the non self-describing segment.

16. A method of sending data between an upper layer sender and an upper layer receiver through a transport having a transport protocol that sends data in at least one transport segment, the method comprising the steps of:

determining if the at least one transport segment is a non self-describing segment;

if the at least one transport segment is a non self-describing segment;

obtaining segment description information;

aligning a framing header with the at least one transport segment;

putting the segment description information in the framing header;

putting the data into the at least one transport segment; and

sending the at least one transport segment to the upper layer receiver.

17. The method of claim 16 wherein the transport segments have a transport segment size and wherein the step of putting the data into the at least one transport segment includes fragmenting the data into self-describing transport segments if a size of the data is larger than the transport segment size.

18. The method of claim 16 wherein the data comprises at least one upper layer protocol data unit and wherein the step of putting the data into a transport segment comprises the step of putting an integral number of upper layer protocol data units into the a transport segment.

19. The method of claim 16 further comprising the step of generating an error message if the data is larger than the smaller of a maximum transport segment size and a size that will fit within the transport segment.

20. A network interface card comprising:

memory buffers for receiving transport segments; and

a processing unit in communication with the memory buffers, the processing unit comprising

a first module for detecting if a transport segment of a transport segment is a non self-describing segment; and

a second module for obtaining segment description information and putting the segment description information in one of a header aligned with a non self-describing segment header and the non self-describing segment header.

21. The network interface card of claim 20 wherein the processing unit aligns the header with the non self-describing segment header.

22. The network interface card of claim 20 wherein the processing unit limits an upper layer protocol data size to the smaller of a maximum transport segment size and a size that will fit within the non self-describing segment.

23. The network interface card of claim 20 wherein the transport segments have a transport segment size and wherein the processing unit fragments data into a plurality of transport segments if a size of the data is larger than the transport segment size.

24. A network interface card comprising:

memory buffers for receiving transport segments; and

a processing unit in communication with the memory buffers, the processing unit performing the steps of;

detecting if a transport segment of a transport protocol is a non self-describing segment; and

if the transport segment is a non self-describing segment;

obtaining segment description information; and

putting the segment description information in one of a header aligned with a non self-describing segment header and the non self-describing segment header.

25. The network interface card of claim 24 wherein the processing unit aligns the header with the non self-describing segment header.

26. The network interface card of claim 24 wherein the processing unit limits an upper layer protocol data size to the smaller of a maximum transport segment size and a size that will fit within the non self-describing segment.

27. The network interface card of claim 24 wherein the transport segments have a transport segment size and wherein the processing unit fragments data into a plurality of transport segments if a size of the data is larger than the transport segment size.