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

Outline Introduction Name Component Encoding (NCE) 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

Introduction 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).

NDN Background 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.

Example: the name /com/google/maps 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.

Packet forwarding in NDN FIB = Forwarding Information Base

Name Prefix Trie for Name lookup

Name Component Encoding (NCE) 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.

Code Allocation Mechanism

ENPT-STA

4 State’s transitions Component edge Empty Entry pointer Next state

CCT-STA

Management of the STA

Build Update Delete incrementally by inserting names one by one modifying the Transition Array directly. Delete setting the second number of corresponding transition entry to 0.

Experimental Results 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.

Effects of Code Allocation Mechanism & Memory Compression

Lookup Time and Speedup & Average Packet Delay

Update Performance