Analysis of a Hybrid Architecture for Cost-Effective Streaming Media Distribution

AnalysisofaHybridArchitectureforCost-E ectiveStreamingMediaDistributionDongyanXua,Heung-KeungChaibCatherine Rosenb ergSunil KulkarniaDepartment of ComputerSciencesbScho ol of Electrical andComputerEngineeringPurdueUniversityWestLafayette,IN47907ABSTRACTTodistributevideoandaudiodatainreal-timestreamingmo de,bothContentDistributedNetwork(CDN)basedandp eer-to-p eer(P2P)architectureshaveb eenprop osed.However,eachhitecturehasitslimitations.CDN servers are exp ensive to deploy and maintain.The storage space and out-b ound bandwidthallo catedtoeachmedia learelimitedandincuracost.Currentsolutionsloweringsuccostusuallycompromise the media quality delivered.On the other hand, a P2P architecture needs a sucientnumber of`seed'supplyingpeersto`jumpstart'thesystem.ComparedwithaCDNserver,p eero ersverylowout-b ound bandwidth.Furthermore, it is not clear how to fairly determine the contribution of each supplying p eer.Inthispap er,we prop oseanovelhybridarchitecturewhichintegrates CDNandP2P based streaming mediadistribution.The architecture is highly cost-e ective:it signi cantly lowers the cost of CDN server resources,withoutcompromising the media qualitydelivered.Furthermore, we prop ose alimitedcontributionpolicyforthe supplying p eers in the system,so that the streaming capacity of supplying p eers is exploited on a limitedandfairbasis.Wepresentanin-depthquantitativanalysisofthehybridsystem.Theanalysis isverywellsupp orted by our extensive simulation results.Keywords:Content Distribution Networks, Peer-to-p eer Systems, Media Streaming, Distributed Systems1.INTRODUCTIONThe proliferation of high-sp eed, broadband networking technologies has made real-time media streaming a reality.Itisincreasingly feasibletodistributevideoandaudio datainreal-timestreaming mo de.Infact,streamingmediadistributionhasb eenanintensivelystudiedresearchtopicthepastfewyears.Amongmostestablished architectures is the Content Distribution Network (CDN), where a large numb er of CDN servers aredeployed at the edge of the Internet, and clients request media streaming service from their closest CDN servers.More recently,ap eer-to-p eer(P2P) basedmediadatadistributionarchitecture isquickly gainingp opularitywhere clients store the data after receiving a streaming service, and act as supplying p eers by streaming the datato other requesting clients (p eers).However, we argue that b oth CDN-based and P2P based architectures havetheir advantages and disadvtages, and each architecture alone do es not provide a cost-e ective and scalablesolution to streaming media distribution.In a CDN for media streaming, data are rst pushed to multiple CDN servers. Each CDN server serves clientswithin a network neighborhood.Besides b eing close to the clients, a CDN server also has large storage spaceand high out-b ound bandwidth.Therefore, a CDN server is exp ected to deliver high-quality streaming mediaservice to its clients.However, it is exp ensive to deploy and maintain CDN servers.The storage space and out-b ound bandwidth allo cated to each media le are limited, and they incur a cost to the contentprovider and/orclients - recall the recently imp osed subscription fee for CNN.com Video.Some solutions try to lower this cost1by adaptively lowering the delivered media quality based on media p opularity and request rate, and thereforelowering the storage space and bandwidth requirement.The downside of this solution is that it compromises theAuthors' contact information:adxu@cs.purdue.edu (Main corresp ondent)bfchaih, cath, sunilkulg@ecn.purdue.edu