1. 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
Presenter : Chai-Yi Chu
Date : 2012/11/28

2. 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

3. 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).

4. 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.

5. 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.

6. Packet forwarding in NDN
FIB = Forwarding Information Base

7. Name Prefix Trie for Name lookup

8. 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.

9. Code Allocation Mechanism

10. ENPT-STA

11. 4
State’s transitions
Component edge
Empty
Entry
pointer
Next
state

12. CCT-STA

13. Management of the STA

14. 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.

15. 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.

17. Effects of Code Allocation Mechanism & Memory Compression

21. Lookup Time and Speedup & Average Packet Delay

26. Update Performance