Low-Power TCAMs for Very Large
Forwarding Tables
Authors: Wencheng Lu and Sartaj Sahni, Fellow, IEEE
Conf. : IEEE/ACM Transactions on networking, 2010
Presenter : JHAO-YAN JIAN
Date : 2011/3/15
1
The simplest TCAM solution
 The 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.
2
SUBTREE SPLIT(CoolCAM)
3
POSTORDER SPLIT(CoolCAM)
4
SUBTREE SPLIT
5
SUBTREE SPLIT
6
POSTORDER SPLIT
 The 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.
7
POSTORDER SPLIT(SP1)
8
POSTORDER SPLIT(SP2)
9
SIMPLE TCAM WITH WIDE SRAM
10
SIMPLE TCAM WITH WIDE SRAM
 25 (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.
11
12
13
14
EXPERIMENTAL RESULTS(1)
15
EXPERIMENTAL RESULTS(2)
16
EXPERIMENTAL RESULTS(3)
17
EXPERIMENTAL RESULTS(4)
18
EXPERIMENTAL RESULTS(5)
19
20