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Policy based Content Delivery An Active Network Approach

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					Policy-based Content Delivery:
An Active Network Approach

           Glen MacLarty
            Michael Fry

  Faculty of Information Technology,
  University of Technology, Sydney
                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
               Motivation
• Numerous content types
• Various forms in which content can be viewed
• Range of available bandwidth




                Policy-based Content Delivery:
                 An Active Network Approach
   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
   Active Network Architecture

Load(URL,Args)                         HTTP Request
                 Dynamic Proxy                          HTTP
                    Server             Proxylet (JAR)   Server


                    Proxylet




                       Policy-based Content Delivery:
                        An Active Network Approach
     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
            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
   ConCEPT cache Architecture

HTTP Request
                                 ConCEPT cache
                                          Request,
               URL             Cache-ID   Cache-ID          Policy
                                                                     Remote Policy
                                                                     Check
                Cache Manager                  Policy Manager            Policy



                                    Proxylet

                      Cache
                                                     Policies
                     (Squid)



                        Policy-based Content Delivery:
                         An Active Network Approach
             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
    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
           Audio Transcoding
                     http://dmir.socs.uts.edu.au/proxylets/StreamManager.jar,
                          streamManager.StreamManager pcm:dvi:dvi:1

                               ConCEPT                                          ConCEPT
                                                   Remote Policy Check

          Request            Cache Manager
                             Policy                                           Policy Manager

                                                    Invoke Proxylet
         Redirect Page      Location Proxylet
                          StreamManager Proxylet                              RTPTranscoder
                                                                      HTTP HEAD
Client                                Query Cache                     Request/Reply       HTTP
                                      Query Policy Database
                                                                                          Request/Reply
                         Streamed Audio

                                 Policy
                                 Cache                                                HTTP
                                Database
                                (Squid)                                               Server




                          Policy-based Content Delivery:
                           An Active Network Approach
            Text Compression
                    http://dmir.socs.uts.edu.au/proxylets/decompressor.jar,
                              Decompressor.Decompressor gzip
         Request
Client                       ConCEPT                                          ConCEPT
                                                Remote Policy Check

         Uncompressed       Cache Manager
                            Policy                                         Policy Manager
                 Text
                                                  Invoke Proxylet
                          Location Proxylet
                        Decompressor Proxylet                                 Compressor
                                                   Compressed Text HTTP HEAD
                                    Query Cache                    Request/Reply       HTTP
                                    Query Policy Database
                                                                                       Request/Reply

                                Policy
                                Cache                                              HTTP
                               Database
                               (Squid)                                             Server




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




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




Policy-based Content Delivery:
 An Active Network Approach

				
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