Selective header field dispatch in a network processing system

• US 20030231625A1
• Filed: 06/13/2002
• Published: 12/18/2003
• Est. Priority Date: 06/13/2002
• Status: Active Grant

• Current Assignee: Lenovo International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Calvignac, Jean Louis, Davis, Gordon Taylor
• Granted Patent: US 7,408,957 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching
• CPC Class Codes: H04L 49/604 Hybrid IP/Ethernet switches
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

A method and structure is disclosed for dispatching appropriate data to a network processing system comprising an improved technique for extracting protocol header fields for use by the network processor. This technique includes basic classification of a packet according to the types of protocol headers present in the packet. Based on the results of the classification, specific parameter fields are extracted from corresponding headers. All such parameter fields from one or more protocol headers in the packet are concatenated into a compressed dispatch message. Multiple of such dispatch messages are bundled into a single composite dispatch message. Thus selected header fields from N packets are passed to the network processor in a single composite dispatch message, increasing the network processor'"'"'s packet forwarding capacity by a factor of N. Likewise, multiple enqueue messages are bundled into a single composite enqueue message to direct enqueue and frame alterations to be taken on the bundle of N packets.

Claims

1. A method of routing packets in a communications network including the acts of:

(a) receiving a packet in a first unit;

(b) selecting a dispatch message format based upon parameters in the packet;

(c) extracting selected fields from protocol headers contained within said packet; and

(d) arranging the selected fields to generate a dispatch message.

2. The method of claim 1 wherein the arranging act includes concatenating the selected fields.

3. The method of claims 1 or 2 further including the act of transmitting the dispatch message.

4. The method in accordance with claims 1 or 2 further including the acts of combining said dispatch message associated with a first packet with more additional dispatch messages associated with other packets into a composite dispatch message.

5. The method of claim 4 further including the act of transmitting the composite dispatch message.

6. The method of claim 4 wherein the composite dispatch message includes a first switch cell having a cell header field concatenated to Composite Frame Header field and a selected number of selected header parameters for different packets chained to the composite frame header field.

7. The method of claim 6 wherein the composite dispatch message further includes a second switch cell having a cell header field and a selected number of selected header fields chained to the cell header field.

20. The method of claim 6 wherein the composite dispatch message further includes n switch cells, n>

1, with each switch cell having a cell header field and a selected number of selected header fields chained to the cell header field.

8. A communications system including:

a data flow unit operatively coupled to at least one input port and at least one output port;

header field extraction sub-system operatively coupled to said data flow, said header field extraction sub-system extracting selected fields from headers contained in received packets and concatenating the selected fields into dispatch messages which are transmitted;

at least one network processor receiving said dispatch messages and generating enqueue messages which are forwarded to said data flow unit; and

switch interface coupling the data flow unit to the network processor.

9. The communications system of claim 8 wherein the at least one data flow unit further includes data flow packet buffer;

and

enqueue frame alteration system for processing enqueue messages received from the at least one network processor.

10. The communications system of claim 8 wherein the at least one network processor includes an embedded processor complex having a plurality of processors;

ingress packet memory;

ingress data flow mechanism coupling said ingress packet memory to the embedded processor complex;

egress packet memory; and

egress data flow mechanism operatively coupling the egress packet memory to the embedded processor complex.

11. A protocol for transmitting data comprising:

a first cell having

a cell header field;

a composite frame header field concatenated to said cell header field; and

a chain of selected header parameter fields operatively coupled to said composite frame header field wherein each of said selected header parameter fields operable to carry selected header parameters extracted from separate network packets.

25. The protocol of claim 11 further including

at least a second cell having

a cell header field and at least one field for carrying payload concatenated to the cell header field.

12. A data flow unit including:

at least one input port;

header field extraction mechanism operatively coupled to the at least one input port, said header field extraction mechanism extracting selected fields from protocol headers contained in packets received by said at least one input port and concatenating the selected fields in a dispatch message;

a switch interface operatively coupled to the data flow unit;

at least one output port; and

enqueue frame alteration mechanism operatively coupled to the switch interface and the at least one output port, said enqueue frame alteration mechanism processing packets in accordance with commands in enqueue message received over the switch interface.

13. The data flow chip of claim 12 wherein the header field extraction mechanism further combines dispatch message associated with a first packet with one dispatch message associated with another packet into a composite dispatch message.

14. The data flow chip of claim 12 wherein the header field extraction mechanism further combines dispatch message associated with a first packet with multiple dispatch messages associated with other packets into a composite dispatch message.

19. The data flow chip of claim 12 further including a packet buffer.

15. A Network Processor including:

an ingress packet memory;

embedded processor complex including a plurality of processors;

ingress data flow coupling the ingress packet memory to the embedded processor complex;

egress packet memory;

egress data flow operatively coupling the egress packet memory to the embedded processor complex;

wherein processors in said processing complex are programmed to independently process each selected header parameter contained in received composite dispatch message combining results for each independently processed selected header into a composite enqueue message.

16. A method to route packets in a communications network comprising the acts of:

receiving a packet in a network unit;

identifying the protocol headers associated with said packet;

selects a dispatch message format appropriate for protocol headers in the packet;

extracting selected fields from the protocol header; and

concatenating the selected fields in a dispatch message.

17. The method of claim 16 further including the act of transmitting the dispatch message.

18. The method of claim 16 further including the act of combining said dispatch message associated with a first packet with at least one additional message associated with at least one dispatch message into a composite dispatch message.

21. A method comprising the acts of:

generating a first cell to transport data having at least a cell header field, a composite frame header field concatenated to the cell header field, TOS field, QID field and delay counter field operatively concatenated to the cell header field, TOS field, QID field and delay counter field operatively concatenated to one another and to the composite frame header field, frame alteration control field concatenated to TOS, QID and Delay Counter Control field and at least one field for carrying payload concatenated to the frame alteration field.

22. The method of claim 21 further including acts of:

loading the first cell with appropriate data; and

transmitting the loaded cell.

23. The method of claim 21 further including the act of generating at least a second cell having a cell header parameter field and at least one field for carrying payload concatenated to the cell header parameter field.

24. The method of claim 23 wherein the payload includes selected header parameters.

26. A method of processing information within a network device comprising the acts of:

(a) receiving in a network processor an aggregate dispatch message containing headers selected from different network packets;

(b) process a header in accordance with forwarding code executed on at least one processor for a selected packet within the aggregate dispatch message;

(c) saving information resulting from processing in step (b);

(d) repeating steps (b) and (c) until all headers in the aggregate dispatch message have been processed; and

(e) forming an aggregate enqueue message with results saved from processing the aggregate dispatch message.

27. The method of claim 26 further including the act of forwarding the aggregate enqueue message.

28. The method of claim 26 wherein the saving act step (c) further includes copying resulting information to a packet memory.

29. The method of claim 26 wherein the forming act step (e) further includes packaging respective results in accordance with a predefined protocol for composite enqueue message.

30. A program product including:

a computer readable medium on which at least one computer program is recorded, said at least one computer program including a first code module containing code that selects header serially within aggregate dispatch messages;

second code module containing code that processes each selected header in accordance with selected instructions and saving information resulting from said processing; and

third code module containing code that formats all saved information into aggregate enqueue message.

31. The program product of claim 30 further including fourth code module containing code that causes the aggregate enqueue message to be forwarded.