System for deriving packet quality of service indicator

• US 7,580,350 B1
• Filed: 04/28/2004
• Issued: 08/25/2009
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Extreme Networks, Inc.
• Inventors: Parker, David K.
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Hom, Shick
• Application Number:
  US10/835,532
• Time in Patent Office: 1,945 Days
• Field of Search: None
• US Class Current: 370/230
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering

Abstract

A system for deriving a quality of service indicator for a packet is described. A register holds a control element. A first resource derives a first candidate quality of service indicator for the packet. A second resource derives a second candidate quality of service indicator for the packet responsive at least in part to the control element held in the register. Resolution logic derives the quality of service indicator for the packet from the first and second candidate quality of service indicators.

Claims

1. A system for deriving a quality of service indicator for a packet comprising:

a register for holding a control element;

a first resource configured to derive a first candidate quality of service indicator for the packet from packet processing state data relating to the packet;

a second resource configured to derive a second candidate quality of service indicator for the packet from packet processing state data relating to the packet responsive to at least a portion of the control element; and

resolution logic for deriving the quality of service indicator for the packet from the first and second candidate quality of service indicators for the packet;

wherein the resolution logic utilizes a configurable priority resolution scheme to select one of the first and second quality of service indicators for assignment to the packet.

2. The system of claim 1 further comprising a memory, wherein the control element is selected from a plurality of control elements held in the memory.

3. The system of claim 2 wherein the plurality of control elements comprises a sequence of control elements.

4. The system of claim 3 wherein the sequence of control elements comprises a sequence of software commands or instructions.

5. The system of claim 1 wherein the first resource comprises logic for mapping packet processing state data relating to the packet into the first candidate quality of service indicator.

6. The system of claim 1 wherein the second resource comprises logic for mapping packet processing state data relating to the packet into the second candidate quality of service indicator responsive to at least the portion of the control element.

7. The system of claim 6 wherein the at least the portion of the control element specifies a mapping mode selected from a plurality of possible mapping modes.

8. The system of claim 1 wherein the second resource comprises logic for searching for a corresponding quality of service indicator using a key derived from packet processing state data relating to the packet responsive to at least the portion of the control element.

9. The system of claim 8 wherein the key is derived from a subset of packet processing state data relating to the packet selected by the values of one or more fields of the control element.

10. The system of claim 1 wherein the resolution logic comprises a packet processor.

13. The system of claim 1 wherein the quality of service indicator for the packet is an egress quality of service indicator.

14. The system of claim 1 wherein the quality of service indicator for the packet is an ingress quality of service indicator.

15. The system of claim 1 wherein the quality of service indicator for the packet is a host quality of service indicator.

16. The system of claim 1 wherein the quality of service indicator for the packet is a multi-dimensional quality of service indicator comprising ingress, egress, and host quality of service indicator components.

17. The system of claim 1 comprising three or more resources, each configured to derive a candidate quality of service indicator for the packet, wherein the resolution logic is configured to derive the quality of service indicator for the packet from the candidate quality of service indicators derived by the three or more resources.

18. The system of claim 1 wherein the first resource is configured to derive the first candidate quality of service indicator responsive to the at least the portion of the control element.

19. The system of claim 1 wherein the first resource is configured to derive the first candidate quality of service indicator independent of the control element.

38. The system of claim 1, wherein the packet processing state data comprises data representative of at least a portion of the packet, data representative of at least a portion of the state of processing of the packet, or both.

11. A system for deriving a quality of service indicator for a packet comprising:

a register for holding a control element;

a first resource configured to derive a first candidate quality of service indicator for the packet from packet processing state data relating to the packet;

a second resource configured to derive a second candidate quality of service indicator for the packet from packet processing state data relating to the packet responsive to at least a portion of the control element; and

resolution logic for deriving the quality of service indicator for the packet from the first and second candidate quality of service indicators for the packet;

wherein the resolution logic includes first resolution logic configured to derive a first priority for the first candidate quality of service indicator, and second resolution logic is configured to derive a second priority for the second candidate quality of service indicator, and the resolution logic is configured to derive the quality of service indicator for the packet from the first and second candidate quality of service indicators, and the first and second priorities.

12. The system of claim 11 wherein the packet has a current quality of service indicator and priority, and the resolution logic is configured to replace the current quality of service indicator for the packet with the first candidate quality of service indicator if the priority of the first candidate quality of service indicator exceeds that of the current quality of service indicator and that of the second candidate quality of service indicator, and replace the current quality of service indicator for the packet with the second candidate quality of service indicator if the priority of the second candidate quality of service indicator exceeds that of the current quality of service indicator for the packet and that of the first candidate quality of service indicator.

39. The system of claim 11, wherein the packet processing state data comprises data representative of at least a portion of the packet, data representative of at least a portion of the state of processing of the packet, or both.

20. In a packet classification system, a method of deriving a quality of service indicator for a packet comprising:

holding a control element in a register;

deriving a first candidate quality of service indicator for the packet from packet processing state data relating to the packet;

deriving a second candidate quality of service indicator for the packet from packet processing state data relating to the packet responsive to at least a portion of the control element; and

deriving the quality of service indicator for the packet from the first and second candidate quality of service indicators for the packet, comprising utilizing a configurable priority resolution scheme to select one of the first and second quality of service indicators for assignment to the packet.

21. The method of claim 20 further comprising selecting the control element from a plurality of control elements held in a memory.

22. The method of claim 21 wherein the plurality of control elements comprises a sequence of control elements.

23. The method of claim 22 wherein the sequence of control elements comprises a sequence of software commands or instructions.

24. The method of claim 20 wherein the first deriving step comprises mapping packet processing state data relating to the packet into the first candidate quality of service indicator.

25. The method of claim 20 wherein the second deriving step comprises mapping packet processing state data relating to the packet into the second candidate quality of service indicator responsive to at least the portion of the control element.

26. The method of claim 25 wherein the at least the portion of the control element specifies a mapping mode selected from a plurality of possible mapping modes.

27. The method of claim 20 wherein the second deriving step comprises searching for a corresponding quality of service indicator using a key derived from packet processing state data relating to the packet responsive to at least the portion of the control element.

28. The method of claim 27 wherein the key is derived from a subset of packet processing state data relating to the packet selected by the values of one or more fields of the control element.

32. The method of claim 20 wherein the quality of service indicator for the packet is an egress quality of service indicator.

33. The method of claim 20 wherein the quality of service indicator for the packet is an ingress quality of service indicator.

34. The method of claim 20 wherein the quality of service indicator for the packet is a host quality of service indicator.

35. The method of claim 20 wherein the quality of service indicator for the packet is a multi-dimensional quality of service indicator comprising ingress, egress and host quality of service indicator components.

36. The method of claim 20 further comprising deriving three or more candidate quality of service indicators for the packet, and deriving the quality of service indicator for the packet from the three or more candidate quality of service indicators.

40. The method of claim 20, wherein the packet processing state data comprises data representative of at least a portion of the packet, data representative of at least a portion of the state of processing of the packet, or both.

29. In a packet classification system, a method of deriving a quality of service indicator for a packet comprising:

holding a control element in a register;

deriving a first candidate quality of service indicator for a packet from packet processing state data relating to the packet;

deriving a second candidate quality of service indicator for the packet from packet processing state data relating to the packet responsive to at least a portion of the control element;

deriving a first priority for the first candidate quality of service indicator,

deriving a second priority for the second candidate quality of service indicator, and

deriving the quality of service indicator for the packet from the first and second candidate quality of service indicators, and the first and second priorities.

30. The method of claim 29 wherein the packet has a current quality of service indicator and priority, and the method further comprises replacing the current quality of service indicator for the packet with the first candidate quality of service indicator if the priority of the first candidate quality of service indicator exceeds that of the current quality of service indicator and that of the second candidate quality of service indicator.

31. The method of claim 29 wherein the packet has a current quality of service indicator and priority, and the method further comprises replacing the current quality of service indicator for the packet with the second candidate quality of service indicator if the priority of the second candidate quality of service indicator exceeds that of the current quality of service indicator and that of the first candidate quality of service indicator.

41. The method of claim 29, wherein the packet processing state data comprises data representative of at least a portion of the packet, data representative of at least a portion of the state of processing of the packet, or both.

37. A system for deriving a quality of service indicator for a packet, the packet having a state, comprising:

means for holding a control element;

first means for deriving a first candidate quality of service indicator for the packet from packet processing state data relating to the packet;

second means for deriving a second candidate quality of service indicator for the packet from packet processing state data relating to the packet responsive to at least a portion of the control element; and

resolution means for deriving the quality of service indicator for the packet from the first and second candidate quality of service indicators for the packet,

by utilizing a configurable priority resolution scheme to select one of the first and second quality of service indicators for assignment to the packet.