1 Range Encoding Cheng-Chien Su

2 Outline DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors  Hao Che, Zhijun Wang, Kai Zheng, Bin Liu  IEEE Trans. Computers, Packet Classifiers In Ternary CAMs Can Be Smaller  Qunfeng Dong, Suman Banerjee, Jia Wang, Dheeraj Agrawal, Ashutosh Shukla  Proc. ACM SIGMetrics, 2006 TCAM Razor: A Systematic Approach Towards Minimizing Packet Classifiers in TCAMs  Chad R. Meiners, Alex X. Liu, Eric Tomg  Proc. IEEE ICNP, 2007 Layered Interval Codes for TCAM-based Classification  Anat Bremler-Barr, Herzliya, David Hay, Danny Hendler, Boris Farber  Proc. ACM SIGMetrics, 2008 Efficient Multi-Match Packet Classification with TCAM  Fang Yu, Randy H. Katz  Proc. IEEE HOTI, 2004

3 DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors (1/5) Why is DRES? Why is Code Vector? Why is Index Vector?

4 DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors (2/5) Dynamic Range Selection Algorithm  Selecting m ranges for encoding out of n ranges.  S i is the number of subranges needed to exactly implement range R i in a TCAM.  E i is the number of rule entries to implement all of the rules that contain range R i.  G i is the encoding gain for R i, defined as the number of rule entries that can be eliminated if R i is encoded. To select m ranges to be encoded, m steps are required, each selecting one range.

5 DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors (3/5)

6 DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors (4/5) Ranges R1-R5 come from the destination port field.  R1{256, 512}, R2{768, 2047}, R3{6000, 6064}, R4{>1023}, R5{512, 1536} Ranges R6-R7 ranges come from the source port field.  R6{>1023}, R7{256, 512}.

7 DRES: Dynamic Range Encoding Scheme for TCAM Coprocessors (5/5)

8 Packet Classifiers In Ternary CAMs Can Be Smaller (1/6) Their proposed techniques for defining semantically equivalent packet classifiers requiring fewer TCAM entries to represent. Expanding Rule Trimming Rule Adding Rule Merging Rule

9 Packet Classifiers In Ternary CAMs Can Be Smaller (2/6) Expanding Rule

10 Packet Classifiers In Ternary CAMs Can Be Smaller (3/6) Trimming Rule

11 Packet Classifiers In Ternary CAMs Can Be Smaller (4/6) Adding Rule

12 Packet Classifiers In Ternary CAMs Can Be Smaller (5/6) Merging Rule

13 Packet Classifiers In Ternary CAMs Can Be Smaller (6/6)

14 TCAM Razor: A Systematic Approach Towards Minimizing Packet Classifiers in TCAMs