System and method for providing transformation of multi-protocol packets in a data stream

• US 6,944,168 B2
• Filed: 05/04/2001
• Issued: 09/13/2005
• Est. Priority Date: 05/04/2001
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: SLT Logic LLC
• Inventors: Paatela, Jeremy B., Sarkinen, Scott A., Trivedi, Hemant Vrajlal
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US09/849,804
• Publication Number:
  US 20020163935A1
• Time in Patent Office: 1,593 Days
• Field of Search: 370/466, 370/412, 370/401, 370/389, 370/392, 370/474, 711/153, 711/170, 711/173, 711/108, 711/104, 711/105, 716/17, 716/16
• US Class Current: 370/401
• CPC Class Codes: H04J 2203/0082 Interaction of SDH with non-ATM protocols
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/12 Protocol engines
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system and method for facilitating packet transformation of multi-protocol, multi-flow, streaming data. Packet portions subject to change are temporarily stored, and acted upon through processing of protocol-dependent instructions, resulting in a protocol-dependent modification of the temporarily stored packet information. Validity tags are associated with different segments of the temporarily-stored packet, where the state of each tag determines whether its corresponding packet segment will form part of the resulting modified packet. Only those packet segments identified as being part of the resulting modified packet are reassembled prior to dispatch of the packet.

Claims

1. A packet transformation module for editing multi-protocol streaming data packets, comprising:

an instruction memory coupled to receive search words identifying a packet type for the packet, wherein the instruction memory outputs appropriate instructions based on the packet type as indexed by the search words;

a packet memory coupled to receive one or more portions of the packet subject to editing, wherein each of the packet portions is stored in a respective memory segment of the packet memory;

a valid bit array having a plurality of memory validity fields associated with respective memory segments, wherein the state of each of the memory validity fields establishes whether the packet portion in the respective memory segment is incorporated into a resulting packet portion; and

a processing module coupled to receive the instructions from the instruction memory, and to edit the packet portions in accordance with the instructions.

2. The packet transformation module as in claim 1, further comprising a priority encoder coupled to the valid bit array to enable output of each of the packet portions associated with asserted ones of the memory validity fields.

3. The packet transformation module as in claim 2, further comprising an output contoller coupled to the priority encoder to output each of the packet portions enabled for output by the priority encoder.

4. The packet transformation module as in claim 3, further comprising an overflow memory to receive and temporarily store second packet portions not subject to editing.

5. The packet transformation module as in claim 4, further comprising a multiplexer coupled to the output controller and the overflow memory to selectively enable transmission of the resulting packet portion from the output controller followed by the second packet portions from the overflow buffer.

6. The packet transformation module as in claim 1, wherein the packet portions are seperated by one or more blank memory segments to facilitate insertion of additional information between existing packet portions stored in the packet memory.

7. The packet transformation module as in claim 6, wherein the resulting packet portion is read out of the packet memory in an order that the packet portions are stored in the packet memory.

8. The packet transformation module as in claim 1, wherein the packet memory is a dual-port packet memory, and wherein the dual-port packet memory concurrently receives two portions of the packet that are subject to editing.

9. The packet transformation module as in claim 1, further comprising a macro sequencer coupled to the packet memory to effect post-processing modifications to the packet portions in the packet memory.

10. The packet transformation module as in claim 9, wherein the post processing modifications comprise at least one of updating a checksum, a time-to live field, a packet conformance marking, and a packet length.

11. A method for editing packets of a packet stream received at a network node, comprising:

storing one or more segments of a packet in partitionable memory segments of a modification memory;

eliciting one or more editing instructions from an instruction memory, wherein the particular editing instructions elicited is based at least in part on characteristics of the packet;

modifying at least one packet segment stored in the modification memory as directed by the editing instructions;

associating validity tags with each of the memory segments to indicate whether or not their corresponding packet segments will be incorporated into a resulting modified packet; and

creating the resulting modified packet by assembling the packet segments associated with the validity tags indicating incorporation into the resulting modified packet.

12. The method of claim 11, further comprising recieving search words corresponding to the characteristics of the packet, wherein the search words are used to index the instruction memory and elicit appropriate editing instructions.

13. The method of claim 11, wherein modifying at least one packet segment of the modification memory includes changing, adding, or deleting one or more packet segments in the modification memory.

14. The method of claim 11, wherein modifying at least one packet segment of the modification memory comprises processing the editing instructions and modifying contents of the modification memory pursuant to the instructions.

15. The method of claim 11, wherein modifying at least one packet segment of the modification memory comprises canceling at least one packet segment by associating an invalid tag with each of the memory segments associated with the canceled packet segment, wherein the invalid tag indicates that the packet segment will not be incorporated into the resulting modified packet.

16. The method of claim 11, wherein storing the packet segments comprises reserving memory space between the stored packet segments.

17. The method of claim 16, wherein modifying at least a portion of the modification memory comprises inserting new packet information in the reserved memory space.

18. The method of claim 11, further comprising interleaving available memory between the parsed portions of the packet in the modification memory, in order to allow insertion of new packet segments.

19. The method of claim 11, wherein associating validity tags comprisess setting a field of one or more bits to a first state when the packet segment is to be included in the modified packet, and setting the field to a second state when the packet segment is not to be included in the modified packet.

20. The method of claim 11, wherein storing the packet segments in the modification memory comprises storing the packet segments in a predetermined arrangement in the modification memory.

21. The method of claim 20, wherein creating the modified packet comprises outputting the packet segments in order of the predetermined arrangement.

22. The method of claim 11, wherein creating the modified packet comprises assembling the packet segments in ascending address order of the modification memory.

23. The method of claim 11, wherein creating the resulting modified packet comprises assembling the packet segments in a predetermined order.

24. The method of claim 11, further comprising determining the characteristics of the packet, including a transmission protocol associated with the packet.

25. The method of claim 24, wherein determining the characteristics of the packet comprises parsing header information of the packet to identify the transmission protocol associated with the packet.

26. The method of claim 11, wherein storing packet segments comprises storing parsed header information corresponding to embedded network layer headers within the packet.

27. The method of claim 11, further comprising effecting policing modifications through direct manipulation of the packet segment in the modification memory after the packet segment has been modified pursuant to the editing instructions.

28. The method of claim 11, further comprising serially receiving the packets from the packet stream.

29. The method of claim 11, further comprising transmitting the resulting modified packet from the network node.

30. The method of claim 11, further comprising separating packet segments subject to modification from packet segments not subject to modification.

31. The method of claim 30, further comprising storing the packet segments not subject to modification in an overflow buffer, wherein no modifications of the packet segments in the overflow buffer are effected.

32. The method of claim 30, wherein the packet segments subject to modification include packet header information.

33. The method of claim 30, wherein the packet segments not subject to modification include packet payload information.

34. The method of claim 11, further comprising:

storing segments of the packet which are not to be modified in an overflow memory;

performing the modifications of the packet segments stored in the modification memory; and

reassembling the packet to create the resulting modified packet.

35. An ingress processing system for editing packets of a data system, comprising:

(A) a packet parser to parse each packet and generate resulting search words based on a packet protocol; and

(B) an editor for editing the packets, comprising;

(i) an instruction memory coupled to the packet parser to receive the search words, wherein the instruction memory outputs targeted instructions based on the packet protocol as indexed by the search words;

(ii) a packet memory coupled to receive one or more portions of the packet subject to editing, wherein each of the packet portions is stored in a respective memory segment of the packet memory;

(iii) a valid bit array having a plurality of memory validity fields associated with respective memory segments, wherein the state of each of the memory validity fields establishes whether the packet portion in the respective memory segment is incorporated into a resulting edited packet; and

(iv) a processing module coupled to receive the instructions from the instruction memory, and to edit the packet portions in accordance with the instructions.

36. A network for transferring information, comprising:

(A) a source node to dispatch information onto the network;

(B) a destination node to receive the information dispatched by the source node;

(C) at least one intermediary node coupled along a transmission path between the source node and the destination node, wherein the intermediary node comprises;

(i) a packet parser to parse each packet and generate resulting search words based on a packet protocol; and

(ii) an editor for editing the packets, comprising;

(a) an instruction memory coupled to the packet parser to receive the search words, wherein the instruction memory outputs targeted instructions based on the packet protocol as indexed by the search words;

(b) a packet memory coupled to receive one or more portions of the packet subject to editing, wherein each of the packet portions is stored in a respective memory segment of the packet memory;

(c) a valid bit array having a plurality of memory validity fields associated with respective memory segments, wherein the state of each of the memory validity fields establishes whether the packet portion in the respective memory segment is incorporated into a resulting edited packet; and

(d) a processing module coupled to receive the instructions from the instruction memory, and to edit the packet portions in accordance with the instructions.

37. The network of claim 36, wherein the intermediary node further comprises a policing engine coupled to the editor to provide measured packet conformance parameters to the editor to carry out post-processing modifications.

38. The network of claim 36, further comprising a switch fabric to direct the resulting edited packet to a subsequent node or the destination node.

39. A computer-readable medium having computer-executable instructions for editing multi-protocol streaming data packets, the computer-executable instructions performing steps comprising:

storing one or more segments of a packet in a partition able memory segments of a modification memory;

eliciting one or more editing instructions from an instruction memory, wherein the particular editing instructions elicited is based at least in part on characteristics of the packet;

modifying at least one packet segment stored in the modification memory as directed by the editing instructions;

associating validity tags with each of the memory segments to indicate whether or not their corresponding packet segments will be incorporated into a resulting modified packet; and

creating the resulting modified packet by assembling the packet segments associated with the validity tags indicating incorporation into the resulting modified packet.

40. A packet transformation module for editing multi-protocol streaming data packets, comprising:

means for storing one or more segments of a packet in partitionable memory segments of a modification memory;

means for eliciting one or more editing instructions from an instruction memory wherein the particular editing instructions elicited is based at least in part on characteristics of the packet;

means for modifying at least one packet segment stored in the modification memory as directed by the editing instructions;

means for associating validity tags with each of the memory segments to indicate whether or not their corresponding packet segments will be incorporated into a resulting modified packet; and

means for creating the resulting modified packet by assembling the packet segments associated with the validity tags indicating incorporation into the resulting modified packet.