Policy-based Content Delivery: An Active Network Approach

1. Policy-based Content Delivery:An Active Network Approach Glen MacLarty Michael Fry Faculty of Information Technology, University of Technology, Sydney

2. Overview • Improve content delivery of web-based objects • Transcoding for unknown content-types • Active network approach to provide additional functionality and greater flexibility Policy-based Content Delivery: An Active Network Approach

3. Motivation • Numerous content types • Various forms in which content can be viewed • Range of available bandwidth Policy-based Content Delivery: An Active Network Approach

4. Active Network Architecture Overview • Dynamic Proxy Servers (DPSs) located throughout the network • DPSs download and load code objects (proxylets) • Proxylets perform specific content or protocol transcoding • Described by Fry & Ghosh Policy-based Content Delivery: An Active Network Approach

5. HTTP Server Load(URL,Args) HTTP Request Proxylet (JAR) Active Network Architecture Dynamic Proxy Server Proxylet Policy-based Content Delivery: An Active Network Approach

6. Benefits of using the Active Network Architecture • Dynamic in nature (Java) • Access to DPSs throughout the active network • Easy deployment (URL to reference proxylets) • DPS provides a security model for proxylets Policy-based Content Delivery: An Active Network Approach

7. ConCEPT cache • Active Network requires caching facilities • Active Network provides facilities useful to caches • User controls the content delivery or transcoding through policies • No requirement on the provider of the content to provide additional formats or transcoding facilities Policy-based Content Delivery: An Active Network Approach

8. HTTP Request Request, Cache-ID Cache-ID Policy URL Remote Policy Check Policy Cache (Squid) Policies ConCEPT cache Architecture ConCEPT cache Policy Manager Cache Manager Proxylet Policy-based Content Delivery: An Active Network Approach

9. Policy Manager • Provides interface for users to modify their policies • Interface for ConCEPT to retrieve policies for specific requests • Manages the storage of policies and policy identifiers (Pcookies) Policy-based Content Delivery: An Active Network Approach

10. Features of the ConCEPT cache • Allows any user to specify cache behaviour • Users can only affect their own requests • Users can define their own proxylets • Proxylets can improve available bandwidth • Additional functionality (language translation) Policy-based Content Delivery: An Active Network Approach

11. http://dmir.socs.uts.edu.au/proxylets/StreamManager.jar, streamManager.StreamManager pcm:dvi:dvi:1 Remote Policy Check Request Policy Manager Cache Manager Policy Manager Invoke Proxylet Redirect Page HTTP HEAD Request/Reply Query Cache HTTP Request/Reply Query Policy Database Streamed Audio Cache (Squid) Policy Database Audio Transcoding ConCEPT ConCEPT StreamManager Proxylet Location Proxylet RTPTranscoder Client HTTP Server Policy-based Content Delivery: An Active Network Approach

12. http://dmir.socs.uts.edu.au/proxylets/decompressor.jar, Decompressor.Decompressor gzip Request Remote Policy Check Uncompressed Text Cache Manager Policy Manager Cache Manager Policy Manager Invoke Proxylet HTTP HEAD Request/Reply Compressed Text Query Cache HTTP Request/Reply Query Policy Database Cache (Squid) Policy Database Text Compression Client ConCEPT ConCEPT Decompressor Proxylet Location Proxylet Compressor HTTP Server Policy-based Content Delivery: An Active Network Approach

13. Future Work • Cache functionality/integration • Additional proxylet implementation • Standardization of proxylet interface • Performance measurements Policy-based Content Delivery: An Active Network Approach

14. Questions? Policy-based Content Delivery: An Active Network Approach