Efficient Gray Code Based Range Encoding Schemes for Packet Classification in TCAM
description
Transcript of Efficient Gray Code Based Range Encoding Schemes for Packet Classification in TCAM
Efficient Gray Code Based Range Encoding Schemes for Packet Classification in TCAM
Author: Yeim-Kuan Chang, Cheng-Chien Su, and Yung-Chieh Lin
Publisher: Submit to Transactions on Computers
Presenter: Chun-Yi Li
Date: 2008/12/24
2
Outline Preliminary
Related Works
EIGC
Perfect-BRGC (P-BRGC)
Performance
3
PreliminaryBuddy Code & BRGC :
Elementary interval
Related WorksDatabase independent & database dependentDirect range-to-prefix conversion:
Database independent schemeConvert each range to prefixes
ex:R=[1,14] prefix = 0001, 001*, 01**, 10**, 110*, 1110Ternary string(Boolean expression)
4
Related Works
Elementary interval based encoding
R1=0101, 0110 R2=0001R3=01** R4=0011, 010*
5
Related WorksParallel packet classification encoding
Proposed Range Encoding Scheme
Scheme based on Elementary Interval and BRGC (EIGC)
Assign each elementary interval a identifier by using BRGC
Default elementary interval have the same code.
7
Proposed Range Encoding Scheme
Scheme based on Perfect BRGC Range Sets (P-BRGC)Definition1:Any range in the set must intersect at least
one of the other ranges
Definition2:A perfect BRGC range sets satifies
(1)Each range contain 2n elementary intervals
(2)Two intersection range A and B in the set, share elementary interval must be
equal to half of the number of elementary interval contained in either A or B.
8
Perfect BRGC range sets
9
Perfect BRGC range sets
10
Virtual endpoint insertShould limit the number of virtual endpoints
Perfect BRGC range sets
Insert a range into layers
11
Performance
12
Performance
13
Performance – All rules
14
Performance - Non-prefix rules
15