Method and apparatus for set intersection rule matching

• US 20030018693A1
• Filed: 07/18/2001
• Published: 01/23/2003
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Cisco Systems Israel Ltd. (Cisco Systems, Inc.)
• Original Assignee: P-Cure Limited
• Inventors: Marko, Reuven A., Finkelman, Ori, Rosenfeld, Amir
• Granted Patent: US 7,027,446 B2
• Time in Patent Office: Days
• US Class Current: 709/200
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/19 at layers above the network layer network arrangements for networked applications for scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A method and apparatus for the implementation of high-speed and memory efficient rule matching in a computer system, the rule matching being performed on an m-dimensional universe with each dimension bound by a given lower and upper coordinate value, and a set of rules that apply to an undetermined number of coordinates in that universe. More specifically, a high-speed computer based packet classification system, without the need for dedicated hardware, uses an innovative set intersection memory configuration to provide efficient matching of packets flowing through a network system to a specific process flow based on a packet tuple. The system also provides classification of packets as they flow through a network system. More particularly, this system provides the correlation of these flowing packets with previously received packets, along with identifying the packets so that they are handled efficiently. The ability to correlate packets to their corresponding process flows permits the implementation of service aware networks (SAN) that are capable of handling network situations at the application level.

Claims

1. A method for checking a rule table, the method comprising:

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, and wherein each of said segments comprises a number of positions;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer;

(ii) receiving a value of a parameter of a rule vector pointed to by said second variable, wherein said third variable is set to the received value;

(iii) setting a bit in the rule table to a logical “

1”

, wherein the bit is identified by a row pointed to by the second variable, at a segment pointed to by the third variable, and in a position pointed to by the first variable;

(iv) increasing the value of the second variable by one; and

(v) while the value of the second variable is smaller than the number of rows continue with operation (ii).

(c) comparing a received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

2. The method according to claim 1, wherein prior to operation (b) (ii) said storing further comprises:

(e) waiting for said rule vector to become available;

(f) waiting for said rule table to have enough free space to store the rule vector;

(g) setting said first variable to point to a next available rule number in said rule table;

(h) setting said second variable to zero; and

wherein after operation (b) (v), said storing further comprises;

(vi) when the value of the second variable is equal to the number of rows, continue with operation (e).

3. The method according to claim 1, wherein said comparing comprises:

(e) utilizing a fourth variable as a row counter, a fifth variable as a parameter pointer, and a sixth variable as a segment pointer;

(f) receiving a value of a rule vector parameter pointed to by said fifth variable, wherein said sixth variable is set to said received value;

(g) performing a logical AND operation between said fifth variable and an identified segment in said rule table, wherein the identified segment is in a row pointed to by said fourth variable, and at a segment pointed to by said sixth variable;

(h) setting said fifth variable to the result of the logical AND operation;

(i) incrementing the value of said fourth variable by one; and

(j) while the value of said fourth variable is smaller than the number of rows, continue with operation (f).

4. The method according to claim 3, wherein prior to operation (f), said method further comprising:

(k) waiting to receive said data vector;

(l) setting said fourth variable to “

0”

;

(m) setting said fifth variable to “

−

1”

; and

wherein after operation (j), said comparing further comprises;

(n) when the value of said fourth variable is equal to the number of rows, returning a value contained in said fifth variable and continuing with operation (k).

5. The method according to claim 4, further comprising:

determining if said fifth variable contains a logical value of “

0”

after performing the logical AND operation, and if so, returning the value contained in said fifth variable and continuing to operation (k);

otherwise continuing with operation (f).

6. The method according to claim 1, wherein the number of rows in said rule table is determined by a number of parameters allowed by said stored rule vectors.

7. The method according to claim 6, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

8. The method according to claim 7, said method further comprising:

providing a range of values to each parameter of said rule vectors.

9. The method according to claim 7, wherein each of the number of positions comprises a bit, wherein the number of bits is determined by a maximum number of rules allowed by a rule checking system.

10. The method according to claim 1, wherein said received data vector is a network tuple utilized in a computer network system.

11. The method according to claim 10, wherein the number of rows in said rule table is determined by a number of parameters in said network tuple.

12. The method according to claim 10, wherein the number of rows in said rule table is determined by a number of bytes in said network tuple.

13. The method according to claim 10, wherein a length of each of the number of rows is determined by a length of one line of a cache memory.

14. The method according to claim 10, wherein a maximum number of parameters of each of said rule vectors is a number of parameters in a network tuple.

15. The method according to claim 10, wherein a maximum number of parameters of each of said rule vectors is a number of bytes in a network tuple.

16. The method according to claim 1, wherein said method is executed on a personal computer (PC).

17. The method according to claim 1, wherein said method is executed on a network processing computer.

18. The method according to claim 1, wherein said received data vector comprises tuple information, so that the comparing can be performed in a network to identify a tuple match with at least one of the stored rule vectors.

20. The system according to claim 19, wherein prior to operation (b) (ii) said storing further comprises:

(e) waiting for said rule vector to become available;

(f) waiting for said rule table to have enough free space to store the rule vector;

(g) setting said first variable to point to a next available rule number in said rule table;

(h) setting said second variable to zero; and

wherein after operation (b) (v), said storing further comprises;

(vi) when the value of the second variable is equal to the number of rows, continue with operation (e).

21. The system according to claim 19, wherein said comparing comprises:

(e) utilizing a fourth variable as a row counter, a fifth variable as a parameter pointer, and a sixth variable as a segment pointer;

(f) receiving a value of a rule vector parameter pointed to by said fifth variable, wherein the sixth variable is set to said received value;

(g) performing a logical AND operation between said fifth variable and an identified segment in said rule table, wherein the identified segment is in a row pointed to by said fourth variable, and at a segment pointed to by said sixth variable;

(h) setting said fifth variable to the result of the logical AND operation;

(i) incrementing the value of said fourth variable by one; and

(j) while the value of said fourth variable is smaller than the number of rows, continue with operation (f).

22. The system according to claim 21, wherein prior to operation (f), said method further comprising:

(k) waiting to receive said data vector;

(l) setting said fourth variable to “

0”

;

(m) setting said fifth variable to “

−

1”

; and

wherein after operation (j), said comparing further comprises;

(n) when the value of said fourth variable is equal to the number of rows, returning a value contained in said fifth variable and continuing with operation (k).

23. The system according to claim 22, further comprising:

determining if said fifth variable contains a logical value of “

0”

after performing the logical AND operation, and if so, returning the value contained in said fifth variable and continuing to operation (k);

otherwise continuing with operation (f).

24. The system according to claim 19, wherein the number of rows in said rule table is determined by a number of parameters allowed by said stored rule vectors.

25. The system according to claim 24, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

26. The system according to claim 25, said method further comprising:

providing a range of values to each parameter of said rule vectors.

27. The system according to claim 25, wherein each of the number of positions comprises a bit, wherein the number of bits is determined by a maximum number of rules allowed by the rule checking system.

28. The system according to claim 19, wherein said received data vector is a network tuple utilized in a computer network system.

29. The system according to claim 28, wherein the number of rows in said rule table is determined by a number of parameters in said network tuple.

30. The system according to claim 28, wherein the number of rows in said rule table is determined by a number of bytes in said network tuple.

31. The system according to claim 28, wherein a length of each of the number of rows is determined by a length of one line of a cache memory.

32. The system according to claim 28, wherein a maximum number of parameters of each of said rule vectors is a number of parameters in a network tuple.

33. The system according to claim 28, wherein a maximum number of parameters of each of said rule vectors is a number of bytes in a network tuple.

34. The system according to claim 19, wherein said method is executed on a personal computer (PC).

35. The system according to claim 19, wherein said method is executed on a network processing computer.

36. The system according to claim 19, wherein said received data vector comprises tuple information, so that the comparing can be performed in a network to identify a tuple match with at least one of the stored rule vectors.

38. The software according to claim 37, wherein prior to operation (b) (ii) said storing further comprises:

(e) waiting for said rule vector to become available;

(f) waiting for said rule table to have enough free space to store the rule vector;

(g) setting said first variable to point to a next available rule number in said rule table;

(h) setting said second variable to zero; and

wherein after operation (b) (v), said storing further comprises;

(vi) when the value of said second variable is equal to the number of rows, continue with operation (e).

39. The software according to claim 37, wherein said comparing comprises:

(e) utilizing a fourth variable as a row counter, a fifth variable as a parameter pointer, and a sixth variable as a segment pointer,

(f) receiving a value of a rule vector parameter pointed to by said fifth variable, wherein said sixth variable is set to said received value;

(g) performing a logical AND operation between said fifth variable and an identified segment in the rule table, wherein the identified segment is in a row pointed to by said fourth variable, and at a segment pointed to by said sixth variable;

(h) setting said fifth variable to the result of the logical AND operation;

(i) incrementing the value of said fourth variable by one; and

(j) while the value of said fourth variable is smaller than the number of rows, continue with operation (f).

40. The software according to claim 39, wherein prior to operation (f, said method further comprising:

(k) waiting to receive said data vector,

(l) setting said fourth variable to “

0”

;

(m) setting said fifth variable to “

−

1”

; and

wherein after operation (j), said comparing further comprises;

(n) when the value of said fourth variable is equal to the number of rows, returning a value contained in said fifth variable and continuing with operation (k).

41. The software according to claim 40, further comprising:

determining if said fifth variable contains a logical value of “

0”

after performing the logical AND operation, and if so, returning the value contained in said fifth variable and continuing to Ad operation (k);

otherwise continuing with operation (f).

42. The software according to claim 37, wherein the number of rows in said rule table is determined by a number of parameters allowed by said stored rule vectors.

43. The software according to claim 42, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

44. The software according to claim 43, said method further comprising:

providing a range of values to each parameter of said rule vectors.

45. The software according to claim 43, wherein each of the number of positions comprise a bit, wherein the number of bits is determined by a maximum number of rules allowed by the rule checking system.

46. The software according to claim 37, wherein said received data vector is a network tuple utilized in a computer network system.

47. The software according to claim 46, wherein the number of rows in said rule table is determined by a number of parameters in said network tuple.

48. The software according to claim 46, wherein the number of rows in said rule table is determined by a number of bytes in said network tuple.

49. The software according to claim 46, wherein a length of each of the number of rows is determined by a length of one line of a cache memory.

50. The software according to claim 46, wherein a maximum number of parameters of each of said rule vectors is a number of parameters in a network tuple.

51. The software according to claim 46, wherein a maximum number of parameters of each of said rule vectors is a number of bytes in a network tuple.

52. The software according to claim 37, wherein the rule checking system is a personal computer (PC).

53. The software according to claim 37, wherein the rule checking system is a network processing computer.

54. The software according to claim 37, wherein said received data vector comprises tuple information, so that the comparing can be performed in a network to identify a tuple match with at least one of the stored rule vectors.

19. A rule table checking system that comprises:

an accessible memory; and

a controller in communication with the accessible memory, wherein said controller is configured to provide rule table checking using a method comprising;

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, and wherein each of said segments comprises a number of positions;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer;

(ii) receiving a value of a parameter of a rule vector pointed to by the second variable, wherein a third variable is set to the received value;

(iii) setting a bit in the rule table to a logical “

1”

, wherein the bit is identified by a row pointed to by the second variable, at a segment pointed to by the third variable, and in a position pointed to by the first variable;

(iv) increasing the value of the second variable by one; and

(v) while the value of the second variable is smaller than the number of rows continue with operation (ii).

(c) comparing a received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

37. Computer software that is utilized in a rule table checking system, the software comprising:

a computer accessible medium having software instructions; and

wherein said software instructions provide rule table checking using a method comprising;

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, and wherein each of said segments comprises a number of positions;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer;

(ii) receiving a value of a parameter of a rule vector pointed to by the second variable, wherein a third variable is set to the received value;

(iii) setting a bit in the rule table to a logical “

1”

, wherein the bit is identified by a row pointed to by the second variable, at a segment pointed to by the third variable, and in a position pointed to by the first variable;

(iv) increasing the value of the second variable by one; and

(v) while the value of the second variable is smaller than the number of rows continue with operation (ii).

(c) comparing a received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

55. A method for checking a rule table having stored rule vectors, the method comprising:

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, and wherein each of said segments comprises a number of positions;

(b) comparing a received data vector to at least one stored rule vector, wherein said comparing comprises;

(i) utilizing a first variable as a row counter, a second variable as a parameter pointer, and a third variable as a segment pointer;

(ii) receiving a value of a rule vector parameter pointed to by said second variable, wherein said third variable is set to said received value;

(iii) performing a logical AND operation between said second variable and an identified segment in the rule table, wherein the identified segment is in a row pointed to by said first variable, and at a segment pointed to by said third variable;

(iv) setting said second variable to the result of the logical AND operation;

(v) incrementing the value of said first variable by one; and

(vi) while the value of said first variable is smaller than the number of rows, continue with operation (ii).

(c) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

56. The method according to claim 55, wherein prior to operation (b) (ii), said method further comprising:

(d) waiting to receive said data vector;

(e) setting said first variable to “

0”

;

(f) setting said fifth variable to “

−

1”

; and

wherein after operation (b) (vi), said comparing further comprises;

(vii) when the value of said first variable is equal to the number of rows, returning a value contained in said second variable and continuing with operation (d).

57. The method according to claim 56, further comprising:

determining if said second variable contains a logical value of “

0”

after performing the logical AND operation, and if so, returning the value contained in said second variable and continuing to operation (d);

otherwise continuing with operation (b) (ii).

58. The method according to claim 55, wherein the number of rows in said rule table is determined by a number of parameters allowed by said stored rule vectors.

59. The method according to claim 58, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

60. The method according to claim 59, said method further comprising:

providing a range of values to each parameter of said rule vectors.

61. The method according to claim 59, wherein each of the number of positions comprises a bit, wherein the number of bits is determined by a maximum number of rules allowed by a rule checking system.

62. The method according to claim 55, wherein said received data vector is a network tuple utilized in a computer network system.

63. The method according to claim 62, wherein the number of rows in said rule table is determined by a number of parameters in said network tuple.

64. The method according to claim 62, wherein the number of rows in said rule table is determined by a number of bytes in said network tuple.

65. The method according to claim 62, wherein a length of each of the number of rows is determined by a length of one line of a cache memory.

66. The method according to claim 62, wherein a maximum number of parameters of each of said rule vectors is a number of parameters in a network tuple.

67. The method according to claim 62, wherein a maximum number of parameters of each of said rule vectors is a number of bytes in a network tuple.

68. The method according to claim 55, wherein said method is executed on a personal computer (PC).

69. The method according to claim 55, wherein said method is executed on a network processing computer.

70. The method according to claim 55, wherein said received data vector comprises tuple information, so that the comparing can be performed in a network to identify a tuple match with at least one of the stored rule vectors.

71. A method for checking an modified rule table, the method comprising:

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, wherein each of said segments comprises a number of positions, and wherein at least one of said segments comprise a “

don'"'"'t care”

segment that identifies a “

don'"'"'t care”

state;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer;

(ii) receiving a value of a parameter of the rule vector pointed to by said second variable, wherein said third variable is set to the received value;

(iii) if a value of said third variable is a “

don'"'"'t care”

designator, setting a bit pointed to by said first variable in said “

don'"'"'t care”

segment to a logical “

1”

;

otherwise, setting a bit in said rule table to a logical “

1”

, wherein the bit is identified by a row pointed to by said second variable, at a segment pointed to by said third variable, and in a position pointed to by said first variable;

(iv) increasing the value of said second variable by one; and

(v) while the value of said second variable is smaller than the number of rows continue with operation (ii);

(c) comparing a received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

72. The method according to claim 71, wherein prior to operation (b)(ii), said storing further comprises:

(e) waiting for said rule vector to become available;

(f) waiting for said rule table to have enough free space to store said rule vector;

(g) setting said first variable to point to a next available rule number in said rule table;

(h) setting said second variable to zero;

wherein after operation (b) (v), said storing further comprises;

(vi) when the value of said second variable is equal to the number of rows, continue with operation (e).

73. The method according to claim 71, wherein the “

don'"'"'t care”

designator is an asterisk (“

*”

).

74. The method according to claim 71, wherein said comparing comprises:

(e) utilizing a fourth variable as a row counter, a fifth variable as a parameter pointer, and a sixth variable as a segment pointer;

(f) receiving a value of a rule vector parameter pointed to by said fifth variable, wherein said sixth variable is set to the received value;

(g) performing a logical OR operation between a rule table content and a “

don'"'"'t care”

segment content, wherein said rule table content is defined by content of a segment that is in a row pointed to by said fourth variable, and in a segment pointed to by said sixth variable, and wherein said “

don'"'"'t care”

content is defined by the content of said “

don'"'"'t care”

segment that is in a row pointed to by said fourth variable;

(h) performing a logical AND operation between the result of said OR operation and said fifth variable;

(i) setting said fifth variable to the result of the logical AND operation;

(j) incrementing the value of said fourth variable by one; and

(k) while the value of said fourth variable is smaller than the number of rows, continue with operation (f).

75. The method according to claim 74, wherein prior to operation (e), said comparing further comprises:

(l) waiting to receive said data vector;

(m) setting said fourth variable to “

0”

;

(n) setting said fifth variable to “

−

1”

; and

wherein after operation (k), said comparing further comprises;

(o) when the value of said fourth variable is equal to the number of rows, returning a value contained in said fifth variable and continuing with operation (l).

76. The method according to claim 75, further comprising:

determining if said fifth variable contains a logical value of “

0”

after performing the logical AND operation, and if so, returning the value contained in said fifth variable and continuing to operation (l);

otherwise continuing with operation (f).

77. The method according to claim 74, wherein said “

don'"'"'t care”

segment is implemented once for those rows for which the same “

don'"'"'t care”

applies.

78. A method according to claim 77, wherein said comparing further comprises:

(e) placing each parameter of said received data vector in a separate variable;

(f) for each group of vectors having one corresponding “

don'"'"'t care”

segment, performing a first logical AND operation between the content of each of the segments belonging to the group;

(g) performing a logical OR operation between a result of said first logical AND operation and a content of the corresponding “

don'"'"'t care”

segment;

(h) performing a second logical AND operation between the results received after performing said logical OR operation; and

(i) returning the value received after performing said second logical AND operation.

79. The method according to claim 78, wherein prior to operation (e), said comparing further comprises:

waiting to receive said data vector.

80. A method for checking an extended rule table having parameters with a range of values, the method comprising:

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, wherein each of said segments comprises a number of positions;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer,

(ii) receiving a value of the parameter of said rule vector pointed to by said second variable, wherein said third variable is set to said received value;

(iii) wherein, if the received value is a range of values, then the method further comprises;

updating a cross reference table with a new sub-rule number for each value in the range of value, including recursive access if necessary;

setting a bit in the rule table to a logical “

1”

, wherein the bit is in a row pointed to by said second variable, at the segment pointed to by a current value of said third variable, and in a position pointed to by said first variable, wherein said setting is repeated while cycling through the range of values,

(iv) increasing the value of said second variable by one; and

(v) while the value of said second variable is smaller than a number of rows continue with operation (b) (ii).

(c) comparing a received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

81. The method according to claim 80, wherein prior to operation (b) (ii), said storing further comprises:

(e) waiting for said rule vector to become available;

(f) calculating an amount of free space required for all the sub-rules possible and waiting for said rule table to have enough free space to store the sub-rules;

(g) setting said first variable to point to a next available rule number in said rule table;

(h) setting said second variable to zero;

wherein after operation (b) (v), said storing further comprises;

(vii) when the value of said second variable is equal to the number of rows, continue with operation (e).

82. The method according to claim 80, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

83. The method according to claim 82, wherein each of the number of segments comprises a number of bits, wherein the number of bits is determined by a maximum number of rules allowed by a rule checking system.

84. The method according to claim 80, said method further comprising:

providing a range of values to each parameter of said rule vectors.

85. The method according to claim 80, said method further comprising:

formatting said range of values as a sequence of a first value followed by a hyphen, and further followed by a second value.

86. The method according to claim 80, said method further comprising:

creating sub-rules from original rules, wherein the sub-rules are configured to handle a range of values, and wherein the sub-rules define the rule vectors; and

providing a sub-rule table, wherein the sub-rule table contains cross reference information so that a corresponding link can be made between the original rules and the sub-rules.

87. A method for checking a modified rule table having parameters with a range value, the method comprising:

(a) providing a two dimensional rule table having a number of rows, wherein each of said rows comprises a number of segments, wherein each of said segments comprises a number of positions;

(b) storing rule vectors in said rule table, wherein said storing comprises;

(i) utilizing a first variable as a rule number position pointer, a second variable as a row counter, and a third variable as a segment pointer;

(ii) receiving a value of the parameter of said rule vector pointed to by said second variable, wherein said third variable is set to said received value;

(iii) wherein, if a value of the parameter of the rule vector pointed to by said second variable is a single value, then setting both said third variable and a fourth variable to the value of the parameter;

otherwise, if the value of the parameter of the rule vector is a range of values, then setting said third variable to a low value of the range of values, and setting said fourth variable to a high value of the range of values;

(iv) setting a bit in the rule table to a logical “

1”

, wherein said bit is identified by a row pointed to by said second variable, at a segment pointed to by said third variable, and in a position pointed to by said first variable;

(v) increasing the value of said third variable by one;

(vi) while the value of said third variable is not larger than the value of said fourth variable continue with operation (iv);

(vii) increasing the value of said second variable by one; and

(viii) while the value of said second variable is smaller than the number of rows continue with operation (iii);

(c) comparing said received data vector to at least one of the stored rule vectors; and

(d) returning a rule number indicator if a match is found between said received data vector and at least one of the stored rule vectors.

88. The method according to claim 87, wherein prior to operation (b) (ii), said storing further comprises:

(e) waiting for said rule vector to become available;

(f) waiting for said rule table to have enough free space to store said rule vector;

(g) setting said first variable to point to the next available rule number in the rule table;

(h) setting said second variable to zero;

wherein after operation (b) (viii), said storing further comprises;

(ix) when the value of said second variable is equal to the number of rows, continue with operation (e).

89. The method according to claim 87, wherein the number of said segments is determined by a maximum number of possible values for said rule vector parameters.

90. The method according to claim 87, wherein each of the number of segments comprises a number of bits, wherein the number of bits is determined by a maximum number of rules allowed by a rule checking system.

91. The method according to claim 87, said method further comprising:

providing a range of values to each parameter of the rule vectors.