IP Library Granted Patent US 8,774,177
Granted Patent B2
US 8,774,177 · App. 10/197,747 · Granted Jul 8, 2014

Classifying traffic at a network node using multiple on-chip memory arrays

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Quick Facts
Patent No.
US 8,774,177
App. No.
10/197,747
Granted
Jul 8, 2014
Kind
B2
Abstract

A technique for classifying traffic at a network node includes programming multiple on-chip memory arrays with identical search entries, receiving multiple packets, and distributing classification searches related to the packets among the multiple on-chip memory arrays. In an embodiment, the on-chip memory arrays are content-addressable memory (CAM) arrays. In another embodiment, the distributing of classification searches related to the packets is performed in an alternating fashion with respect to a fixed order.

Claims (34)

1. A method of classifying traffic at a network node comprising:

programming multiple on-chip memory arrays with identical search entries, wherein the multiple on-chip memory arrays are identically programmed with search entries of a first on-chip memory array of the multiple on-chip memory arrays identical to search entries of a second on-chip memory array of the multiple on-chip memory arrays;

receiving multiple packets; and

distributing classification searches related to said packets among said multiple programmed on-chip memory arrays during simultaneous operation of all of said identically programmed on-chip memory arrays;

wherein said multiple packets have a fixed order prior to said distributing of classification searches related to said packets, and wherein said distributing of classification searches related to said packets is performed according to said fixed order in an alternating fashion with respect to said fixed order.

2. The method of claim 1 wherein said distributing of classification searches related to said packets alternates at each clock cycle.

3. The method of claim 1 wherein the number of said multiple programmed on-chip memory arrays is two.

4. The method of claim 1 wherein the multiple on-chip memory arrays are of a same type.

5. A method of classifying traffic at a network node comprising:

programming multiple content addressable memory (CAM) arrays with identical search entries, wherein the multiple CAM arrays are identically programmed with search entries of a first CAM array of the multiple CAM arrays identical to search entries of a second CAM array of the multiple CAM arrays, wherein said search entries are class-specific entries, each of said class-specific entries having an associated traffic distribution policy;

receiving multiple packets;

distributing classification searches related to said packets among said multiple programmed CAM arrays during simultaneous operation of all of said identically programmed CAM arrays;

obtaining a protocol-independent key field from a packet of the multiple packets;

searching one of said multiple programmed CAM arrays with said protocol-independent key field for a class-specific entry that matches said protocol-independent key field to identify an associated traffic distribution policy for said packet; and

applying said identified traffic distribution policy to said packet.

6. The method of claim 5 wherein said multiple packets have a fixed order prior to said distributing of classification searches related to said packets, and wherein said distributing of classification searches related to said packets is performed according to said fixed order.

7. The method of claim 6 wherein said distributing of classification searches related to said packets is performed in an alternating fashion with respect to said fixed order.

8. The method of claim 7 wherein said distributing of classification searches related to said packets alternates at each clock cycle.

9. The method of claim 5 wherein the number of said multiple programmed CAM arrays is two.

10. The method of claim 5 wherein each of said class-specific entries has an associated traffic class, and wherein the method further comprises:

searching one of said multiple programmed CAM arrays with said protocol-independent key field for the class-specific entry that matches said protocol-independent key field to identify an associated traffic class of said packet.

11. A system for classifying traffic at a network node comprising:

a plurality of on-chip memory arrays configured to be programmed identically with search entries of a first on-chip memory array of the plurality of on-chip memory arrays identical to search entries of a second on-chip memory array of the plurality of on-chip memory arrays; and

a search distribution engine configured to distribute a plurality of classification searches related to a plurality of incoming packets among said plurality of on-chip memory arrays during simultaneous operation of all of said identically programmed on-chip memory arrays, wherein said search distribution engine is further configured to distribute said classification searches in an alternating fashion to said plurality of on-chip memory arrays.

12. The system of claim 11 wherein the multiple on-chip memory arrays are of a same type.

13. A system for classifying traffic at a network node comprising:

a plurality of content addressable memory (CAM) arrays configured to be programmed identically with search entries of a first CAM array of the plurality of CAM arrays identical to search entries of a second CAM array of the plurality of CAM arrays, wherein said CAM arrays are configured to be programmed identically with multiple class-specific entries, each of said class-specific entries having an associated traffic distribution policy;

a search distribution engine configured to distribute a plurality of classification searches related to a plurality of incoming packets among said plurality of CAM arrays during simultaneous operation of all of said identically programmed CAM arrays;

a key field extraction engine configured to obtain a protocol-independent key field from an incoming packet of said plurality of incoming packets;

a traffic classification module configured to search one of said CAM arrays with said protocol-independent key field to identify an associated traffic distribution policy for said incoming packet; and

a traffic distribution engine configured to apply said identified traffic distribution policy to said incoming packet.

14. The system of claim 13 wherein said search distribution engine distributes said classification searches in an alternating fashion to said plurality of CAM arrays.

15. The system of claim 13 wherein each of said class-specific entries has an associated traffic class, and

wherein the traffic classification module is further configured to search one of said CAM arrays with said protocol-independent key field to identify an associated traffic class of said incoming packet.

Assignments (5)
RELEASE OF SECURITY INTEREST Recorded Sep 30, 2014
From: CREDIT SUISSE AG
To: ALCATEL LUCENT
Reel/Frame 033868/0555 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 8, 2014
From: ALCATEL-LUCENT USA INC.
To: ALCATEL LUCENT
Reel/Frame 033260/0710 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 4, 2014
From: RIVERSTONE NETWORKS, INC.
To: LUCENT TECHNOLOGIES INC.
Reel/Frame 033024/0736 →
MERGER Recorded Jun 4, 2014
From: LUCENT TECHNOLOGIES INC.
To: ALCATEL-LUCENT USA INC.
Reel/Frame 033024/0790 →
SECURITY AGREEMENT Recorded Jan 30, 2013
From: ALCATEL LUCENT
To: CREDIT SUISSE AG
Reel/Frame 029821/0001 →