1

A Novel Scalable IPv6 Lookup Scheme Using Compressed Pipelined Tries

Author:Michel Hanna, Sangyeun Cho, and Rami MelhemPublisher:NETWORKING 2011Presenter:Han-Chen ChenDate:2011/5/11

2

Introduction IPv6 packet forwarding

IPv4 trie based packet forwarding algorithms port to IPv6 Trie height Memory

TCAM High power consumption Poor scalability to long IPv6 prefixes

Hash-based hardware engines Constant search time Collision chaining causes unbounded memory acces

s time

3

Introduction The outcome of any IP lookup operation is an interface (or

output port) number. Real-life backbone routers contain a relatively small

number of output ports The routers assign many next hop addresses to one output

port. This means that the number of unique next hop information

is greater than the number of output ports.

4

Introduction

5

Multibit trie

(a) Multibit trie for Figure 1(a) with strides {3, 2, 2}. (b) Its leaf-pushed trie.

6

Uncompressed multibit trie

-2 : with child link

-1 : null

>0 : port number

7

Compressed multibit trie

Inter-Node Compressed TrieUncompressed trie Compressing the leaves

8

Performance Evaluation (1/5)

Statistics of IPv6 tables on June 2010. H is the number of output ports.

9

Performance Evaluation (2/5)

Number of INCT trie levels vs. total memory (KB) for Linx2 and Eugene1

10

Performance Evaluation (3/5)

Memory (KB) of INCT(7) vs. Uncompressed(7) trie

11

Performance Evaluation (4/5)

Memory (MB) of Lulea(6)/Tree Bitmap, INCT(6), MIPS(57) and Binary INCT(57).MIPS & Binary INCT {8,1…56} Lulea & INCT {16,16,8,8,8,8}

12

Performance Evaluation (5/5)