Towards Peer-Assisted Dynamic Adaptive Streaming over HTTP

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Paper "Towards Peer-Assisted Dynamic Adaptive Streaming over HTTP" from the IEEE Packet Video Workshop 2012

Text of Towards Peer-Assisted Dynamic Adaptive Streaming over HTTP

  • 1. Wo r ks h o p | P V 2 0 1 21 9 t h I nte r n at i o n a lPa c ket V i d e o Towards Peer-Assisted Dynamic Adaptive Streaming over HTTPMay 10-11 2012 Stefan Lederer, Christopher Mller and MunichGermany Christian Timmerer
  • 2. Introduction Video streaming needs huge bandwidth ressources Can other peers be used to reduce the server load and save costs? Can this be integrated into DASH?PV 2012 | Peer-Assisted DASH Slide 2
  • 3. Towards Peer-Assisted DASH Reduction of server load Clients offer their downloaded segments Segment requests are monitored by server Integration in DASH MPD for future clients Intelligent Scheduling Algorithms necessary When to load from peer, when from server? Error Handling, etc.PV 2012 | Peer-Assisted DASH Slide 3
  • 4. Peer Assisted Streaming Peer Traffic Non-symmetric Internet Connection Bottleneck: Low Upload Resources Split segments to smaller sub-chunks Restrict number of accepted connection at client Limit connection duration to prevent stalls Target: Reduce server bandwidth by 10 - 20 %PV 2012 | Peer-Assisted DASH Slide 4
  • 5. Peer Assisted StreamingPV 2012 | Peer-Assisted DASH Slide 5
  • 6. Implementation Proof of Concept using DASH VLC Plugin + PHP for server-side implementation Provides basic proof of concept and shows weaknesses to improve Problem: Amount of clients too low Detailed Evaluation in Omnet++ Larger scale simulation with 40 clients Deterministic client behaviour scenariosPV 2012 | Peer-Assisted DASH Slide 6
  • 7. MPD Tracking Server (1) MPD Import Imports original MPD to database MPD Generator Generates MPD based on database Including other peers using Client has the possibility to update its MPD Use @MediaRange to signal segment size Use ZIP compression to reduce MPD sizePV 2012 | Peer-Assisted DASH Slide 7
  • 8. MPD Tracking Server (2) and Client Modifications File Tracker Gateway for segment access Segment + Representation as parameter Stores client IP + timestamp for upcoming MPD requests Response: the requested segment Local HTTP Server + Buffer at Client Store segments to disc and provide them on demand via a local HTTP serverPV 2012 | Peer-Assisted DASH Slide 8
  • 9. MPD Example http://www.cdn.com/tracker.php?file= Server URL with File Tracker http://client1-IP/example Peers offering http://client2-IP/example the segment http://client1-IP/example ...PV 2012 | Peer-Assisted DASH Slide 9
  • 10. Peer Assisted DASH ExamplePV 2012 | Peer-Assisted DASH Slide 10
  • 11. Evaluation OMNet++ Simulation framework INET framework for protocol stack HTTP Client/Server implementation DASH Client based on DASH VLC Plugin / libDASH MPD Generator + Segment Tracker using external MySQL databasePV 2012 | Peer-Assisted DASH Slide 11
  • 12. Evaluation Settings Bitrate Resolution 101 kbit/s. 320x240 201 kbit/s. 480x360 395 kbit/s. 480x360 800 kbit/s. 854x480 1372 kbit/s. 853x480 1992 kbit/s. 1280x720 2995 kbit/s. 1920x1080 3992 kbit/s. 1920x1080 4979 kbit/s. 1920x1080 5936 kbit/s. 1920x1080PV 2012 | Peer-Assisted DASH Slide 12
  • 13. Simulation 1: Results Server 6 Mbps maximum Representation limit Clients select different representations according to their downlink speed Number of clients offering one specific segment is - 15 % lowPV 2012 | Peer-Assisted DASH Slide 13
  • 14. Simulation 2: Results - Server 1,4 Mbps maximum Representation limit Clients select the same maximum representation Downlink speed of all clients is sufficient - 25 % Lower upload time for segmentsPV 2012 | Peer-Assisted DASH Slide 14
  • 15. Simulation Results Example Client Client: 8 Mbps Downlink Activation at second 214 of the simulation Simulation 2: 1,4 Mbps max. Representation limitPV 2012 | Peer-Assisted DASH Slide 15
  • 16. Cost Saving Possibilities Simulation 1: 15 % traffic cost reduction Total costs: US$ 4.14 per hour Savings: US$ 0.62 per hour Additionally: Reduced reserved bandwidth capacityPV 2012 | Peer-Assisted DASH Slide 16
  • 17. Conclusions Torwards Peer-Assisted DASH Peer-assited streaming using standard-compliant DASH MPDs Maintainance of DASH advantages Relative simple system design and implementation work Evaluation simulation Up to 25 % bandwidth savings Directly convertable to CDN cost reductionsPV 2012 | Peer-Assisted DASH Slide 17
  • 18. Conclusions & Further Work Much more possibilities Intelligent client clustering in larger scale environments Peer management & download algorithm improvements MPD update improvements Detailed CDN cost analysis Evaluation of some Set-Top box scenarios Integration to Content Centric Networking (CCN)PV 2012 | Peer-Assisted DASH Slide 18
  • 19. 1 9 t h I nte r n at i o n a l Pa c ket V i d e o 2012 MunichGermany Wo r ks h o p | P V 2 0 1 2May 10-11 The END http://dash.itec.aau.at