Experimental Evaluation of Content Distribution with NDN and HTTP

1. Experimental Evaluation ofContent Distribution with NDN and HTTP Authors: Haowei Yuan and Patrick Crowley Publisher:2013 Proceedings IEEE INFOCOM Presenter: Chia-Yi Chu Date: 2013/08/14

2. Outline • Introduction • Experimental Setup • File Distribution Performance • Improving CCNx Performance

3. Introduction (1/2) • Name-centric network architectures • Data requests need to have unique names • In-network storage elements that can cache the data and respond to matching requests. • Named-Data Networking (NDN) • Interest packets • containing the name of the requested content • Data packets • containing both the name and its associated data • NDN routers cache Data packets • Entries in a cache indexed by their names.

4. Introduction (2/2) • HTTP infrastructure • URLs are the names that matter most in today’s Internet. • The requested URL in the HTTP header is the content name. • Including both web servers and caching proxies, can be viewed as providing in-network storage for named HTTP data. • Evaluate the effectiveness of NDN and HTTP as content distribution systems over a range of experimental scenarios.

5. Experimental Setup (1/3) • Test bed • Open Network Laboratory (ONL) • 48 single-core machines • AMD 2.0GHz Operon Processor, with 512MB memory and 1Gbps network interface • Connected via virtual switches Network Processor-based Routers (NPRs)

6. Experimental Setup (2/3) • CCNx Software Tools • ccnx-0.4.0, release on Sep. 15, 2011. • ccnd daemon • Configured with default • underlying transportation protocol is TCP • Built-in ccncatchunks2 • Generate a sequence of Interest packets • ccnfileserver • Generate Data packets with content fetched from files on server

7. Experimental Setup (3/3) • HTTP and Web-Caching Software Tools • Lighttpd-1.4.28 • Squid-3.41.11 • Both using default configurations • wget • For downloading files

8. File Distribution Performance (1/11) • The metric • Download Time (DT) • the time from when a client application sends a request for a file until the file is downloaded completely.

9. File Distribution Performance (2/11) • Experimental Configuration • 40 client hosts, 1 server, and 2 levels of intermediate nodes • 8 clients form a cluster, and shared a common second level intermediate node • Connected via 1Gbps links • 100MB file is stored in server, clients try to fetch file simultaneously

10. File Distribution Performance (3/11)

11. File Distribution Performance (4/11) • CCNx vs. Lighttpd • downloading 100MB file • without a caching proxy • Start with 1 client in each cluster • Active 1 clients each round until all clients are active

12. File Distribution Performance (5/11)

13. File Distribution Performance (6/11) • CCNx vs. Squid • Single level case • all the clients connect to the server through the top level CCNx router or Squid proxy • Two level case • clients are connected via a second level cache

14. File Distribution Performance (7/11)

15. File Distribution Performance (8/11) • Lossy Network Condition • Emulate a lossylink • Rand drop plugin, which probabilistically selects and drops packets on the NPRs. • Emulate delay • Delay plugin to an NPR connected with the link. • 1 MB file

16. File Distribution Performance (9/11)

17. File Distribution Performance (10/11)

18. File Distribution Performance (11/11)

19. Improving CCNx Performance (1/2) • CCNx employs an XML encoding scheme to encode packets to wire format. • The original CCNx implementation • stores content with their names encoded in the Content Store (CS) • when the CS is queried, several content names might need to be decoded • Asimple change • decoded content names are stored in the CS.

20. Improving CCNx Performance (2/2)