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Scalable Name Lookup in NDN Using Effective Name Component Encoding

Authors : Yi Wang, Keqiang He, Huichen Dai, Wei Meng, Junchen Jiang, Bin Liu, and Yan Chen.

Publisher : IEEE International Conference on Distributed Computing Systems - 2012

Presenter : Chai-Yi Chu

Date : 2012/11/28

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Introduction◦NDN Background◦ Packet forwarding in NDN◦Name Prefix Trie for Name lookup

Name Component Encoding (NCE)◦Code Allocation Mechanism◦ State Transition Arrays for Encoded Name Prefix Trie

(ENPT-STA)

◦ State Transition Arrays for Component Character Trie (CCT-STA)

◦Management of the State Transition Arrays Experimental Results

Outline

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Name Component Encoding (NCE) on a name set containing 3,000,000 names. ◦ reduces overall 30% memory.◦ performs a few millions lookups per second

(on an Intel 2.8 GHz CPU).

Introduction

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NDN◦Named Data Networking◦ concentrates on the content itself (“what”), rather than

“where” information is located.◦ content in NDN network is assigned a name.◦NDN routes and forwards packets by these names, rather than

IP addresses.

NDN Background

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An NDN name ◦ hierarchically structured and composed of explicitly delimited

components Delimiters areusually slash (‘/’) or dot (‘.’), are not part of the

name.

Example: the name /com/google/maps◦ com, google and maps are three components of the name.

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FIB = Forwarding Information Base

Packet forwarding in NDN

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Name Prefix Trie for Name lookup

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A memory efficient Code Allocation Mechanism◦ to shorten the bytes which represent a code by reducing the

total number of codes. Ameliorate State Transition Arrays◦ for trie structure to compress memory size and accelerate

longest prefix lookup. algorithms of managing the STA ◦ to satisfy the frequent name update in NDN.

Name Component Encoding (NCE)

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Code Allocation Mechanism

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ENPT-STA

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State’s transitions

Component edge

Empty

Entry pointer

Next state

Empty

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CCT-STA

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Management of the STA

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Build◦ incrementally by inserting names one by one

Update◦modifying the Transition Array directly.

Delete ◦ setting the second number of corresponding transition entry to

0.

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NCT and NCE mechanism are implemented in C. The memory cost and time performance◦measured on a PC

with an Intel Core 2 Duo CPU of 2.8 GHz and DDR2 SDRAM of 8 GB.

Domain name information◦DOMZ – 3,004,388 domains.◦Blacklist – 2,050,886 domains◦ALEXA – 1,000,000 domains.

Experimental Results

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Effects of Code Allocation Mechanism & Memory Compression

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Lookup Time and Speedup & Average Packet Delay

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Update Performance