Method and apparatus for network load balancing using indirection RAM during classification

1. A network device comprising:

a content-addressable memory (“CAM”) configured to provide an index in accordance with information stored in a header of a packet;

a memory coupled to the CAM and configured to provide information regarding number of paths from source devices to destination devices in accordance with the index, wherein the memory provides a base index value and a range number, wherein the range number indicates number of alternative paths associated with the base index value;

a hash component coupled to the memory and configured to generate a hash index in response to the base index value and the range number, wherein the hash index indicates a less congested path to route the packet; and

a result memory coupled to the hash component and capable of identifying a classification result in response to the hash index.

2. The device of claim 1 , further comprising:

a key generator coupled to the memory and configured to generate a key in response to a packet.

3. The device of claim 1 , wherein the memory is an indirection random access memory (“RAM”).

4. The device of claim 3 , wherein the indirection RAM is an on-chip storage memory.

5. The device of claim 1 , wherein the base index value is one of the number of paths for a packet to travel from a source device to a destination device.

6. The device of claim 1 , wherein the range number is an offset value indicating physical storage locations in the memory associated from the base index value for storing number of possible paths for a packet to travel from a source device to a destination device.

7. The device of claim 6 , wherein the base index value is a reference address for the range number.

8. The device of claim 1 , wherein the hash component is capable of generating the less congested path for a packet to travel from the source device to the destination device utilizing addition of the base index value with hashed value of the range number.

9. A method for network load balancing, comprising:

receiving an index from a content-addressable memory (“CAM”) in accordance with a packet;

obtaining a base index and a range number representing number of possible paths between a source device and a destination device from a memory in response to the index;

identifying an alternative path addressed by the range number and the base index in the memory;

generating a hash index in response to the range number and the base index; and

fetching a result indicating a less congested path for packet routing from a result memory in response to the hash index.

10. The method of claim 9 , further comprising classifying a packet in accordance with the result.

11. The method of claim 10 , wherein fetching a result indicating a less congested path for packet routing from a result memory in response to the hash index further include selecting one of a plurality of results in a result random access memory (“RAM”) in response to the hash index.

12. The method of claim 9 , wherein receiving an index from a content-addressable memory (“CAM”) in accordance with a packet further includes, receiving the packet from a port;

generating a key in response to the packet; and

forwarding the key to the CAM.

13. The method of claim 9 , wherein obtaining a base index and a range number representing number of possible paths further includes, accessing an indirection random access memory (“RAM”) in accordance with the index; and

fetching the range number from a storage location in the indirection RAM.

14. The method of claim 13 , wherein fetching the range number further includes utilizing the index to address the storage location for storing the range number in the indirection RAM.

15. The method of claim 9 , wherein generating a hash index in response to the range number and the base index further includes,

hashing the range number to generate a hashed number; and

adding the hashed number to the base index;

wherein the hash index indicates a path capable of transmitting the packet in a line rate to travel from the source device to the destination device.

16. An apparatus having a content-addressable memory (“CAM”), a memory, and a routing chip, for network load balancing, comprising:

means for receiving an index from the CAM in accordance with a packet;

means for obtaining a base index and a range number representing number of possible paths between a source device and a destination device from the memory in response to the index;

means for identifying an alternative path addressed by the range number and the base index in the memory;

means for generating a hash index in response to the range number and the base index; and

means for fetching a result indicating a less congested path for packet routing from a result memory in response to the hash index.

17. The apparatus of claim 16 , further comprising means for classifying a packet in accordance with the result.

18. The apparatus of claim 17 , wherein means for fetching a result indicating a less congested path for packet routing from a result memory in response to the hash index further include means for selecting one of a plurality of results in a result random access memory (“RAM”) in response to the hash index.

19. The apparatus of claim 16 , wherein means for receiving an index from the CAM in accordance with a packet further includes,

means for receiving the packet from a port;

means for generating a key in response to the packet; and

means for forwarding the key to the CAM.

20. The apparatus of claim 16 , wherein means for obtaining a base index and a range number representing number of possible paths further includes,

means for accessing an indirection random access memory (“RAM”) in accordance with the index; and

means for fetching the range number from a storage location in the indirection RAM.

21. The apparatus of claim 20 , wherein means for fetching the range number further includes means for utilizing the index to address the storage location for storing the range number in the indirection RAM.

22. The apparatus of claim 16 , wherein means for generating a hash index in response to the range number and the base index further includes,

means for hashing the range number to generate a hashed number; and

means for adding the hashed number to the base index;

wherein the hash index indicates a path capable of transmitting the packet in a line rate to travel from the source device to the destination device.