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Low-Power TCAMs for Very Large Forwarding Tables
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Transcript of Low-Power TCAMs for Very Large Forwarding Tables
Authors: Wencheng Lu and Sartaj Sahni, Fellow, IEEE
Conf. : IEEE/ACM Transactions on networking, 2010Presenter : JHAO-YAN JIANDate : 2011/3/15
Low-Power TCAMs for Very Large Forwarding Tables
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The simplest TCAM solutionThe simplest TCAM solution to packet
forwarding requires one TCAM search and one SRAM access to forward a packet.
The power consumption is that for a TCAM of this size.
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SUBTREE SPLIT(CoolCAM)
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POSTORDER SPLIT(CoolCAM)
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SUBTREE SPLIT
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SUBTREE SPLIT
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POSTORDER SPLITThe DTCAM buckets are filled using as
many rounds of feasible tree carving and packing as needed to completely carve out .
In each round, we select the bucket B with the fewest forwarding-table prefixes.
The preorder traversal.
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POSTORDER SPLIT(SP1)
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POSTORDER SPLIT(SP2)
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SIMPLE TCAM WITH WIDE SRAM
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SIMPLE TCAM WITH WIDE SRAM25 (50) is a rather crude estimate of the number
of instructions needed to process a 72-bit (144-bit) suffix node.
We can make 100 M SRAM accesses per second using a 10-ns SRAM and perform about 20 G instruction per second using a 3.2-GHz dual-core processor.
Therefore, about 200 instructions can be executed in the time it takes to make an SRAM access.
The time to process a 72-bit (144-bit) suffix node is only about 1/8 (1/4) that of an SRAM access.
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EXPERIMENTAL RESULTS(1)
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EXPERIMENTAL RESULTS(2)
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EXPERIMENTAL RESULTS(3)
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EXPERIMENTAL RESULTS(4)
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EXPERIMENTAL RESULTS(5)
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