Classification search scheme and rules engine for network unit

• US 20040095936A1
• Filed: 01/08/2003
• Published: 05/20/2004
• Est. Priority Date: 11/15/2002
• Status: Abandoned Application

• Current Assignee: 3Com Corporation (HP Inc.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Moran, Paul J., Choi, Kam, OʼNeill, Eugene
• Application Number:
  US10/338,170
• Publication Number:
  US 20040095936A1
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/583 Stackable routers
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]

Abstract

A classification search engine for the application of classification rules to a data packet comprises a rules engine for applying a succession of rules, each rule including an operating code. At least some rules are each a single rule of which the operating code specifies a respective portion of the packet, such as a longword, for the extraction of data for the application of the respective rule. Each single rule includes a mask field for controlling the application of the single rule to the data. Other rules are multiple rules of which the operating codes identifies the rule as a multiple rule and which includes a mask for controlling the application of the multiple rule to the results of the application of a multiplicity of single rules to the packet. The operating code for a single rule specifies a pre-determined packet type and a decoder will determine whether a packet conforms to this type (which may be specific or generic) before allowing the application of the rule to the packet.

Claims

1. A classification search apparatus for a network unit which is operative to receive and forward addressed data packets, comprising:

a temporary store for a segment of data relating to a received packet;

a store for classification rules at least some of which include a field of reference data and an operating code, said operating code defining a starting location in said segment for a packet data field to be compared with said reference data; and

a rules engine for applying a multiplicity of said classification rules for successive application to said segment of data.

2. Apparatus according to claim 1 wherein each of said classification rules includes a mask field for controlling comparison between said reference data and said packet data field.

3. Apparatus according to claim 1 wherein at least some of said classification rules each have an operating code identifying a predetermined type of packet.

4. Apparatus according to claim 3 and further comprising means for determining whether the packet conforms to said predetermined type before allowing the application of a classification rule to the packet data field.

5. Apparatus according to claim 1 wherein at least one classification rule comprises an operating code which indicates termination of a classification search.

6. Apparatus according to claim 1, further comprising a storage array for storing the results of the application of a multiplicity of classification rules to selected data fields in said segment;

and wherein said rules engine applies a multiple rule to said results.

7. Apparatus according to claim 6 wherein said storage array stores a limited succession of said results.

8. Apparatus according to claim 6 wherein said multiple rule comprises a mask field for application to said results and an operating code distinguishing the multiple rule.

9. Apparatus according to claim 1 wherein at least some of the rules each include a field indicating whether the respective rule is an inclusion rule or an exclusion rule.

10. A classification search engine for the application of classification rules to a data segment, comprising:

a rules engine for applying a succession of rules, each rule including an operating code, wherein;

at least some of said rules are each a single rule of which the operating code specifies a portion of said data segment for the extraction of data for the application of the respective rule, each single rule including a mask field for controlling the application of the single rule to said data segment; and

at least one rule is a multiple rule of which the operating code identifies the rule as a multiple rule and which includes a mask for controlling the application of the multiple rule to the results of the application of a multiplicity of single rules to the packet.

11. A classification search engine according to claim 10 wherein the operating code for each single rule identifies a predetermined packet type.

12. A classification search engine according to claim 10 wherein the operating code of each single rule specifies a selectable offset from a reference point in the segment.

13. A classification search engine according to claim 10 wherein at least some of the rules each include a field indicating whether the respective rule is an inclusion rule or an exclusion rule.

14. A classification search engine for the application of classification rules to a data segment including data from a data packet, comprising:

a rules engine for applying a succession of rules, each rule comprising an operating code, wherein;

at least some rules are each a single rule of which the operating code

(a) identifies a predetermined packet type; and

(b) specifies in accordance with said predetermined packet type a data field in said data segment for the extraction of data for the application of the respective rule, each single rule including a mask field for controlling the application of the single rule to said data field

15. A classification search engine according to claim 14 wherein said data field is a longword.

16. A classification search engine according to claim 14, wherein:

at least one rule is a multiple rule of which the operating code identifies that rule as a multiple rule and which includes a mask for controlling the application of the multiple rule to the results of the application of a multiplicity of single rules to the data segment.

17. A classification search engine according to claim 14 and further comprising means for determining whether said data packet conforms to said pre-determined type before allowing the application of a rule to the data segment

18. A classification search engine according to claim 14 wherein at least some of the rules each include a field indicating whether the respective rule is an inclusion rule or an exclusion rule.