Method, system, and program for managing congestion in a network controller

• US 7,929,442 B2
• Filed: 06/30/2004
• Issued: 04/19/2011
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Gaur, Daniel R., Connor, Patrick L., Cornett, Linden
• Primary Examiner(s): Rao; Seema S
• Assistant Examiner(s): Baron; Henry
• Application Number:
  US10/882,534
• Publication Number:
  US 20060013128A1
• Time in Patent Office: 2,484 Days
• Field of Search: 370/230, 370/236, 370/229, 370/233, 370/232, 370/236.1, 370/252, 370/253, 370/395
• US Class Current: 370/235
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 43/026 using flow identification

Abstract

Provided are a method, system, and program for managing congestion in a network controller, which in one embodiment, substantially all packets having an assigned priority value below a selected priority level are culled. In another embodiment, selected flows of packets into a network controller are culled at selected culling rates. In one example, a selected flow may be drastically culled. In another example, all flows may be culled at a certain rate which does not exceed a maximum for each flow. In another example, culling techniques may be combined.

Claims

1. A method of a processor performing operations, the operations comprising:

determining the level of packet traffic coming into a network controller;

selecting a priority level as a function of the determined traffic level;

assigning priority values to incoming packets;

accepting and processing incoming packets having an assigned priority value above said selected priority level; and

culling incoming packets having an assigned priority value below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets having a priority below said selected priority level to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level;

wherein said accepting and processing incoming packets having an assigned priority value above said selected priority level includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

2. The method of claim 1 wherein said determining includes determining a first traffic level;

said selecting includes selecting a first priority level wherein all packets have a priority greater than said first priority level so that said culling culls no packets, and said accepting and processing accepts and processes all packets;

wherein in response to an increase in traffic level, said determining includes determining a second traffic level higher than said first traffic level;

said selecting includes selecting a second priority level higher than said first priority level wherein a first type of packets each has a priority level below said second priority level so that said culling culls packets of said first type and, wherein the remaining packets are of types having a priority greater than said second priority level so that said accepting and processing accepts and processes all packets except said packets of said first type; and

wherein in response to a further increase in traffic level, said determining includes determining a third traffic level higher than said second traffic level;

said selecting includes selecting a third priority level higher than said second priority level wherein a second type of packets and said first type of packets each have a priority level below said third priority level so that said culling culls packets of said first type and said second type, wherein the remaining packets are of a third type having a priority greater than said third priority level so that said accepting and processing accepts and processes all packets except said packets of said first type and said second type.

3. The method of claim 2 wherein said culling of packets of said first type includes queuing said packets of said first type in a queue of packets of said first type and discarding packets of said first type when said queue of packets of said first type is full, and said culling of packets of said second type includes queuing said packets of said second type in a queue of packets of said second type and discarding packets of said second type when said queue of packets of said second type is full.

4. The method of claim 1 wherein said priority values include a first priority value and a second priority value higher than said first priority value and wherein said culling culls packets of said first priority value and said assigning assigns said first priority value to at least one type of packets selected from a first group of packet types which consists of Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

5. The method of claim 4 wherein accepting and processing accepts and processes incoming packets having said second priority value and said assigning assigns said second priority value to at least one type of packets selected from a second group of packet types which consists of Internet Protocol fragmented packets, Transmission Control Protocol ACK packets.

6. A method of a processor performing operations, the operations comprising:

determining the level of packet traffic coming into a network controller of a host from a plurality of sources external to said host;

identifying individual traffic flows of packets within said incoming packets, each individual traffic flow having a separate network protocol connection between an external source and an internal destination of the network controller host;

selecting as a function of said determined traffic level, at least one traffic flow for culling;

selecting as a function of said determined traffic level, another traffic flow for accepting and processing incoming packets of said another traffic flow;

selecting as a function of said traffic level, a culling rate for each traffic flow to be culled; and

culling selected traffic flows to be culled at said selected culling rates wherein said culling includes at least one of a) queuing at least some incoming packets in a processing suspension queue to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets of said another traffic flow includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

7. The method of claim 6 wherein all identified traffic flows are selected for culling at a particular traffic level.

8. The method of claim 6 wherein each selected culling rate is a percentage of packets to be discarded within a flow wherein the packets culled from each selected flow does not exceed a predetermined maximum percentage for each flow.

9. The method of claim 6 wherein said culling includes periods of culling alternating with periods of no culling and said culling rate selecting includes selecting a first proportion of lengths of culling periods relative to lengths of periods of no culling.

10. The method of claim 9 wherein said culling rate selecting includes selecting a second proportion of lengths of culling periods relative to lengths of periods of no culling wherein said second proportion is larger than said first proportion and is selected as a function of a second traffic level higher than said first traffic level.

11. The method of claim 6 wherein said culling rate selecting includes selecting a first culling rate for a first flow, and selecting a second culling rate higher than said first culling rate, for a second flow.

12. The method of claim 11 wherein said traffic flow selecting includes assigning priority values to said first and second flows and wherein said second flow is assigned a priority value lower than the assigned priority value of said first flow.

13. The method of claim 12 wherein said flow culling includes assigning priority values to packets of flows, discarding queued packets of said second flow having a first priority value, accepting and processing packets of said second flow having a second priority value higher than said first priority value.

14. The method of claim 13 wherein said assigning assigns said first priority value to packets of at least one type selected from a first group of packet types which consists of Internet Protocol fragmented packets which initiate a set of fragmented packets to be reassembled, packets to be stored in an empty buffer, unacknowledged packets stored in a buffer, Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

15. The method of claim 13 wherein said assigning assigns said second priority value to packets of at least one type selected from a second group of packet types which consists of Internet Protocol fragmented packets which complete a set of fragmented packets, packets which complete a partially full receive buffer, Transmission Control Protocol ACK packets.

16. The method of claim 13 wherein said assigning assigns said first priority value to a first portion of a single packet in which said first portion is to be stored in an empty buffer and assigns said second priority value to a second portion of said single packet in which said second portion completes a partially full receive buffer.

17. The method of claim 6 wherein said flow selecting is a function of at least one factor selected from a group of factors consisting of flow protocol, flow payload application, flow Transmission Control Protocol window size, flow Transmission Control Protocol window utilization, flow offload engine utilization.

18. The method of claim 11 wherein said second culling rate culls packets of said second flow.

19. An article comprising at least one of hardware and a combination of hardware and software, said at least one including machine readable instructions stored on the hardware that when executed, causes the machine to:

determine the level of packet traffic coming into a network controller;

select a priority level as a function of the determined traffic level;

assign priority values to incoming packets;

accept and process incoming packets having an assigned priority value above said selected priority level; and

cull incoming packets having an assigned priority value below the selected priority wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets having a priority below said selected priority level to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets having an assigned priority value above said selected priority level includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

20. The article of claim 19 wherein said determining includes determining a first traffic level;

said selecting includes selecting a first priority level wherein all packets have a priority greater than said first priority level so that said culling culls no packets, and said accepting and processing accepts and processes all packets;

wherein in response to an increase in traffic level, said determining includes determining a second traffic level higher than said first traffic level;

said selecting includes selecting a second priority level higher than said first priority level wherein a first type of packets each has a priority level below said second priority level so that said culling culls packets of said first type and, wherein the remaining packets are of types having a priority greater than said second priority level so that said accepting and processing accepts and processes all packets except said packets of said first type; and

wherein in response to a further increase in traffic level, said determining includes determining a third traffic level higher than said second traffic level;

said selecting includes selecting a third priority level higher than said second priority level wherein a second type of packets and said first type of packets each have a priority level below said third priority level so that said culling culls packets of said first type and said second type, wherein the remaining packets are of types having a priority greater than said third priority level so that said accepting and processing accepts and processes all packets except said packets of said first type and said second type.

21. The article of claim 20 wherein said culling of packets of said first type includes queuing said packets of said first type in a queue of packets of said first type and discarding packets of said first type when said queue of packets of said first type is full, and said culling of packets of said second type includes queuing said packets of said second type in a queue of packets of said second type and discarding packets of said second type when said queue of packets of said second type is full.

22. The article of claim 19 wherein said priority values include a first priority value and a second priority value higher than said first priority value and wherein said culling culls packets of said first priority value and said assigning assigns said first priority value to at least one type of packets selected from a first group of packet types which consists of Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

23. The article of claim 22 wherein accepting and processing accepts and processes incoming packets having said second priority value and said assigning assigns said second priority value to at least one type of packets selected from a second group of packet types which consists of Internet Protocol fragmented packets, Transmission Control Protocol ACK packets.

24. An article comprising at least one of hardware and a combination of hardware and software, said at least one including machine readable instructions stored on the hardware that when executed, causes the machine to:

determine the level of packet traffic coming into a network controller of a host from a plurality of sources external to said host;

identify individual traffic flows of packets within said incoming packets, each individual traffic flow having a separate network protocol connection between an external source and an internal destination of the network controller host;

select as a function of said determined traffic level, at least one traffic flow for culling;

select as a function of said determined traffic level, another traffic flow for accepting and processing incoming packets of said another traffic flow;

select as a function of said traffic level, a culling rate for each traffic flow to be culled; and

cull selected traffic flows at said selected culling rates wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets of said another traffic flow includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

25. The article of claim 24 wherein all identified traffic flows are selected for culling at a particular traffic level.

26. The article of claim 24 wherein each selected culling rate is a percentage of packets to be discarded within a flow wherein the packets culled from each selected flow does not exceed a predetermined maximum percentage for each flow.

27. The article of claim 24 wherein said culling includes periods of culling alternating with periods of no culling and said culling rate selecting includes selecting a first proportion of lengths of culling periods relative to lengths of periods of no culling.

28. The article of claim 27 wherein said culling rate selecting includes selecting a second proportion of lengths of culling periods relative to lengths of periods of no culling wherein said second proportion is larger than said first proportion and is selected as a function of a second traffic level higher than said first traffic level.

29. The article of claim 24 wherein said culling rate selecting includes selecting a first culling rate for a first flow, and selecting a second culling rate higher than said first culling rate, for a second flow.

30. The article of claim 29 wherein said traffic flow selecting includes assigning priority values to said first and second flows and wherein said second flow is assigned a priority value lower than the assigned priority value of said first flow.

31. The article of claim 30 wherein said flow culling includes assigning priority values to packets of flows, discarding packets of said second flow having a first priority value, accepting and processing packets of said second flow having a second priority value higher than said first priority value.

32. The article of claim 31 wherein said assigning assigns said first priority value to packets of at least one type selected from a first group of packet types which consists of Internet Protocol fragmented packets which initiate a set of fragmented packets to be reassembled, packets to be stored in an empty buffer, unacknowledged packets stored in a buffer, Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

33. The article of claim 31 wherein said assigning assigns said second priority value to packets of at least one type selected from a second group of packet types which consists of Internet Protocol fragmented packets which complete a set of fragmented packets, packets which complete a partially full receive buffer, Transmission Control Protocol ACK packets.

34. The article of claim 31 wherein said assigning assigns said first priority value to a first portion of a single packet in which said first portion is to be stored in an empty buffer and assigns said second priority value to a second portion of said single packet in which said second portion completes a partially full receive buffer.

35. The article of claim 24 wherein said flow selecting is a function of at least one factor selected from a group of factors consisting of flow protocol, flow payload application, flow Transmission Control Protocol window size, flow Transmission Control Protocol window utilization, flow offload engine utilization.

36. The article of claim 29 wherein said second culling rate culls packets of said second flow.

37. A system for use with a network, comprising:

at least one system memory which includes an operating system;

a motherboard;

a processor mounted on the motherboard and coupled to the memory;

an expansion card coupled to said motherboard;

a network adapter mounted on said expansion card; and

a device driver executable by the processor in the system memory for said network adapter, wherein the network adapter is adapted to;

determine the level of packet traffic coming into said network adapter;

select a priority level as a function of the determined traffic level;

assign priority values to incoming packets;

accept and process incoming packets having an assigned priority value above said selected priority level; and

cull incoming packets having an assigned priority value below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets having a priority below said selected priority level to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level;

wherein said accepting and processing incoming packets having an assigned priority value above said selected priority level includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

38. The system of claim 37 wherein said determining includes determining a first traffic level;

said selecting includes selecting a first priority level wherein all packets have a priority greater than said first priority level so that said culling culls no packets, and said accepting and processing accepts and processes all packets;

wherein in response to an increase in traffic level, said determining includes determining a second traffic level higher than said first traffic level;

said selecting includes selecting a second priority level higher than said first priority level wherein a first type of packets each has a priority level below said second priority level so that said culling culls packets of said first type and, wherein the remaining packets are of types having a priority greater than said second priority level so that said accepting and processing accepts and processes all packets except said packets of said first type; and

wherein in response to a further increase in traffic level, said determining includes determining a third traffic level higher than said second traffic level;

said selecting includes selecting a third priority level higher than said second priority level wherein a second type of packets and said first type of packets each have a priority level below said third priority level so that said culling culls packets of said first type and said second type, wherein the remaining packets are of types having a priority greater than said third priority level so that said accepting and processing accepts and processes all packets except said packets of said first type and said second type.

39. The system of claim 38 wherein said adapter is adapted to maintain queues of packets and wherein said culling of packets of said first type includes queuing said packets of said first type in a queue of packets of said first type and discarding packets of said first type when said queue of packets of said first type is full, and said culling of packets of said second type includes queuing said packets of said second type in a queue of packets of said second type and discarding packets of said second type when said queue of packets of said second type is full.

40. The system of claim 37 wherein said priority values include a first priority value and a second priority value higher than said first priority value and wherein said culling culls packets of said first priority value and said assigning assigns said first priority value to at least one type of packets selected from a first group of packet types which consists of Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

41. The system of claim 40 wherein accepting and processing accepts and processes incoming packets having said second priority value and said assigning assigns said second priority value to at least one type of packets selected from a second group of packet types which consists of Internet Protocol fragmented packets, Transmission Control Protocol ACK packets.

42. A system for use with a network having a plurality of sources, comprising:

at least one system memory which includes an operating system;

a plurality of packet destinations within said system;

a motherboard;

a processor mounted on the motherboard and coupled to the memory;

an expansion card coupled to said motherboard;

a network adapter mounted on said expansion card and having a transport protocol offload engine and a plurality of buffers; and

a device driver executable by the processor in the system memory for said network adapter wherein the network adapter is adapted to;

determine the level of packet traffic coming into said network adapter of a host from a plurality of sources external to said host;

identify individual traffic flows of packets within said incoming packets, each individual traffic flow having a separate network protocol connection between a network source and a destination of the system;

select as a function of said determined traffic level, at least one traffic flow for culling;

select as a function of said determined traffic level, another traffic flow for accepting and processing incoming packets of said another traffic flow;

select as a function of said traffic level, a culling rate for each traffic flow to be culled; and

cull selected traffic flows at said selected culling rates wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets of said another traffic flow includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

43. The system of claim 42 wherein all identified traffic flows are selected for culling at a particular traffic level.

44. The system of claim 42 wherein each selected culling rate is a percentage of packets to be discarded within a flow wherein the packets culled from each selected flow does not exceed a predetermined maximum percentage for each flow.

45. The system of claim 42 wherein said culling includes periods of culling alternating with periods of no culling and said culling rate selecting includes selecting a first proportion of lengths of culling periods relative to lengths of periods of no culling.

46. The system of claim 45 wherein said culling rate selecting includes selecting a second proportion of lengths of culling periods relative to lengths of periods of no culling wherein said second proportion is larger than said first proportion and is selected as a function of a second traffic level higher than said first traffic level.

47. The system of claim 42 wherein said culling rate selecting includes selecting a first culling rate for a first flow, and selecting a second culling rate higher than said first culling rate, for a second flow.

48. The system of claim 47 wherein said traffic flow selecting includes assigning priority values to said first and second flows and wherein said second flow is assigned a priority value lower than the assigned priority value of said first flow.

49. The system of claim 48 wherein said flow culling includes assigning priority values to packets of flows, discarding packets of said second flow having a first priority value, accepting and processing packets of said second flow having a second priority value higher than said first priority value.

50. The system of claim 49 wherein said assigning assigns said first priority value to packets of at least one type selected from a first group of packet types which consists of Internet Protocol fragmented packets which initiate a set of fragmented packets to be reassembled, packets to be stored in an empty buffer of said adapter, unacknowledged packets stored in a buffer of said adapter, Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

51. The system of claim 49 wherein said assigning assigns said second priority value to packets of at least one type selected from a second group of packet types which consists of Internet Protocol fragmented packets which complete a set of fragmented packets, packets which complete a partially full receive buffer of said adapter, Transmission Control Protocol ACK packets.

52. The system of claim 49 wherein said assigning assigns said first priority value to a first portion of a single packet in which said first portion is to be stored in an empty buffer of said adapter and assigns said second priority value to a second portion of said single packet in which said second portion completes a partially full receive buffer of said adapter.

53. The system of claim 42 wherein said flow selecting is a function of at least one factor selected from a group of factors consisting of flow protocol, flow payload application, flow Transmission Control Protocol window size, flow Transmission Control Protocol window utilization, offload engine utilization.

54. The system of claim 47 wherein said second culling rate culls packets of said second flow.

55. A device for use with packets coming from a network, comprising:

a network controller adapted to;

determine the level of packet traffic coming into said network controller;

select a priority level as a function of the determined traffic level;

assign priority values to incoming packets;

accept and process incoming packets having an assigned priority value above said selected priority level; and

cull incoming packets having an assigned priority value below the selected priority level wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets having a priority below said selected priority level to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets having an assigned priority value above said selected priority level includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

56. The device of claim 55 wherein said determining includes determining a first traffic level;

said selecting includes selecting a first priority level wherein all packets have a priority greater than said first priority level so that said culling culls no packets, and said accepting and processing accepts and processes all packets;

wherein in response to an increase in traffic level, said determining includes determining a second traffic level higher than said first traffic level;

said selecting includes selecting a second priority level higher than said first priority level wherein a first type of packets each has a priority level below said second priority level so that said culling culls packets of said first type and, wherein the remaining packets are of types having a priority greater than said second priority level so that said accepting and processing accepts and processes all packets except said packets of said first type; and

wherein in response to a further increase in traffic level, said determining includes determining a third traffic level higher than said second traffic level;

said selecting includes selecting a third priority level higher than said second priority level wherein a second type of packets and said first type of packets each have a priority level below said third priority level so that said culling culls packets of said first type and said second type, wherein the remaining packets are of types having a priority greater than said third priority level so that said accepting and processing accepts and processes all packets except said packets of said first type and said second type.

57. The device of claim 56 wherein said adapter is adapted to maintain queues of packets and wherein said culling of packets of said first type includes queuing said packets of said first type in a queue of packets of said first type and discarding packets of said first type when said queue of packets of said first type is full, and said culling of packets of said second type includes queuing said packets of said second type in a queue of packets of said second type and discarding packets of said second type when said queue of packets of said second type is full.

58. The device of claim 55 wherein said priority values include a first priority value and a second priority value higher than said first priority value and wherein said culling culls packets of said first priority value and said assigning assigns said first priority value to at least one type of packets selected from a first group of packet types which consists of Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

59. The device of claim 58 wherein accepting and processing accepts and processes incoming packets having said second priority value and said assigning assigns said second priority value to at least one type of packets selected from a second group of packet types which consists of Internet Protocol fragmented packets, Transmission Control Protocol ACK packets.

60. A device for use with a network having a plurality of sources, comprising:

at least one device memory which includes an operating device;

a plurality of packet destinations within said system;

a motherboard;

a processor mounted on the motherboard and coupled to the memory;

an expansion card coupled to said motherboard;

a network adapter mounted on said expansion card and having a transport protocol offload engine and a plurality of buffers; and

a device driver executable by the processor in the system memory for said network adapter wherein the network adapter is adapted to;

determine the level of packet traffic coming into said network adapter of a host from a plurality of sources external to said host;

identify individual traffic flows of packets within said incoming packets, each individual traffic flow having a separate network protocol connection between a network source and a destination of the system;

select as a function of said determined traffic level, at least one traffic flow for culling;

select as a function of said determined traffic level, another traffic flow for accepting and processing incoming packets of said another traffic flow;

select as a function of said traffic level, a culling rate for each traffic flow to be culled; and

cull selected traffic flows at said selected culling rates wherein said culling includes at least one of a) queuing in a processing suspension queue at least some incoming packets to separate said packets being culled from unculled incoming packets and suspending processing of all of said packets in said queue, and b) discarding at least some incoming packets having a priority below the selected priority level so that incoming packets having an assigned priority value below the selected priority level are culled as a function of the determined traffic level;

wherein said accepting and processing incoming packets of said another traffic flow includes bypassing said culling so that said queuing in a processing suspension queue and said discarding are both bypassed so that incoming packets having an assigned priority value above the selected priority level bypass said culling as a function of the determined traffic level.

61. The device of claim 60 wherein all identified traffic flows are selected for culling at a particular traffic level.

62. The device of claim 60 wherein each selected culling rate is a percentage of packets to be discarded within a flow wherein the packets culled from each selected flow does not exceed a predetermined maximum percentage for each flow.

63. The device of claim 60 wherein said culling includes periods of culling alternating with periods of no culling and said culling rate selecting includes selecting a first proportion of lengths of culling periods relative to lengths of periods of no culling.

64. The device of claim 63 wherein said culling rate selecting includes selecting a second proportion of lengths of culling periods relative to lengths of periods of no culling wherein said second proportion is larger than said first proportion and is selected as a function of a second traffic level higher than said first traffic level.

65. The device of claim 60 wherein said culling rate selecting includes selecting a first culling rate for a first flow, and selecting a second culling rate higher than said first culling rate, for a second flow.

66. The device of claim 65 wherein said traffic flow selecting includes assigning priority values to said first and second flows and wherein said second flow is assigned a priority value lower than the assigned priority value of said first flow.

67. The device of claim 66 wherein said flow culling includes assigning priority values to packets of flows, discarding packets of said second flow having a first priority value, accepting and processing packets of said second flow having a second priority value higher than said first priority value.

68. The device of claim 67 wherein said assigning assigns said first priority value to packets of at least one type selected from a first group of packet types which consists of Internet Protocol fragmented packets which initiate a set of fragmented packets to be reassembled, packets to be stored in an empty buffer of said adapter unacknowledged packets stored in a buffer of said adapter, Internet Control Message Protocol packets, Address Resolution Protocol packets, Transmission Control Protocol SYN packets.

69. The device of claim 67 wherein said assigning assigns said second priority value to packets of at least one type selected from a second group of packet types which consists of Internet Protocol fragmented packets which complete a set of fragmented packets, packets which complete a partially full receive buffer of said adapter, Transmission Control Protocol ACK packets.

70. The device of claim 67 wherein said assigning assigns said first priority value to a first portion of a single packet in which said first portion is to be stored in an empty buffer of said adapter , and assigns said second priority value to a second portion of said single packet in which said second portion completes a partially full receive buffer of said adapter .

71. The device of claim 60 wherein said flow selecting is a function of at least one factor selected from a group of factors consisting of flow protocol, flow payload application, flow Transmission Control Protocol window size, flow Transmission Control Protocol window utilization, offload engine utilization.

72. The device of claim 65 wherein said second culling rate culls packets of said second flow.