System and method for handling out-of-order frames

• US 20040042458A1
• Filed: 08/29/2003
• Published: 03/04/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Elzu, Uri
• Granted Patent: US 7,411,959 B2
• Time in Patent Office: Days
• US Class Current: 370/394
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2898 Subscriber equipments DSL modems H04M11/062; cable modems H04L12/2801
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• 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 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• 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 49/9063 Intermediate storage in different physical parts of a node or terminal
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 69/10 Streamlined, light-weight or high-speed protocols, e.g. express transfer protocol [XTP] or byte stream
• 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 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Aspects of the invention may be found in a method and system for handling out-of-order frames. In one embodiment, a method includes, for example, one or more of the following: receiving an out-of-order frame via a network interface card (NIC); placing data of the out-of-order frame in a host memory; and managing information relating to one or more holes in a receive window.

Claims

1. A method for handling out-of-order frames, comprising:

(a) receiving an out-of-order frame via a network subsystem;

(b) placing data of the out-of-order frame in a host memory; and

(c) managing information relating to one or more holes in a receive window.

2. The method according to claim 1, wherein the out-of-order frame is received via a TCP offload engine (TOE) of the network subsystem or a TCP-enabled Ethernet controller (TEEC) of the network subsystem.

3. The method according to claim 1, wherein the network subsystem does not store the out-of-order frame on an onboard memory.

4. The method according to claim 3, wherein the network subsystem does not store one or more missing frames relating to the out-of-order frame.

5. The method according to claim 1, wherein the network subsystem comprises a NIC.

6. The method according to claim 1, wherein (b) comprises placing the data of the out-of-order frame in the host memory if the out-of-order frame is determined to be inside the receive window.

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

dropping the out-of-order frame if the out-of-order frame is determined not to be inside the receive window.

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

placing a portion of the data of the out-of-order frame in the host memory, the portion of the data being inside the receive window.

9. The method according to claim 1, wherein (c) comprises one or more of the following:

storing information relating to a new hole created by the placement of the data of the out-of-order frame,

updating information relating to an existing hole modified by the placement of the data of the out-of-order frame, and

deleting information relating to a plugged hole created by the placement of the data of the out-of-order frame.

10. The method according to claim 9,

wherein the stored information resides on the network subsystem,

wherein the updated information resides on the network subsystem, and

wherein the deleted information resided on the network subsystem.

11. The method according to claim 1, wherein the managed information resides on the network subsystem.

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

updating the receive window based upon the placement of the data of the out-of-order frame.

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

setting a programmable limit with respect to a number of holes allowed in the receive window.

14. The method according to claim 1, wherein (b) comprises mapping TCP space into host buffer space.

15. The method according to claim 1, wherein the network subsystem comprises a memory whose memory usage scales with a number of holes in the receive window.

16. The method according to claim 1, wherein the network subsystem comprises a memory whose memory usage does not scale with a number of out-of-order frames received.

17. A method for handling out-of-order frames, comprising:

parsing an out-of-order frame into control information and data information;

processing at least one of the control information, the data information and context information to determine a buffer location in a host memory in which to place the data information; and

managing receive window hole information.

18. The method according to claim 17, wherein a network subsystem is adapted to parse the out-of-order frame into control information and data information.

19. The method according to claim 17, wherein a network subsystem is adapted to process at least one of the control information, the data information and the context information to determine the buffer location in the host memory in which to place the data information.

20. The method according to claim 17, wherein a network subsystem is adapted to manage receive window hole information generated by the placement of the data information.

21. The method according to claim 20, wherein a network subsystem is adapted to store the receive window hole information managed by the network subsystem.

22. The method according to claim 17, wherein the receive window hole information comprises TCP receive window hole information.

23. A system for handling out-of-order frames, comprising:

a host comprising a host memory; and

a network subsystem coupled to the host via a host interface,

wherein the network subsystem is adapted to process an out-of-order frame,

wherein the network subsystem is adapted to place data of the out-of-order frame in a host memory, and

wherein the network subsystem is adapted to manage information relating to one or more holes in a receive window.

24. The system according to claim 23, wherein the network subsystem comprises a TOE or a TEEC that provides flow-through processing and placement of the data of the out-of-order frame in the host memory.

25. The system according to claim 23, wherein the data is placed in a temporary buffer, an upper layer protocol (ULP) buffer or an application buffer residing in the host memory.

26. The system according to claim 23, wherein the network subsystem is adapted to process at least one of control information and data of the out-of-order frame to determine a buffer location in the host memory in which to place the data.

27. The method according to claim 23, wherein the network subsystem is adapted to store the information relating to the one or more holes in the receive window.

28. The method according to claim 23, wherein the network subsystem is not adapted to store the out-of-order frame on the network subsystem until one or more missing frames are received by the network subsystem.

29. The method according to claim 23, wherein the network subsystem comprises a NIC.