The Holy Grail: Media on Demand over Multicast

1. The Holy Grail:Media on Demand over Multicast Doron Rajwan CTO Bandwiz

2. Outline • Problems with broadband content on demand • The caching (CDN) solution • What about multicast? • Bandwiz solution: Broadband Content on Demand Over Multicast • Summary

3. The ChallengeBroadband Content Delivery

4. Content Delivery Infrastructure

5. Unicast Content Delivery

6. Unicast Content Delivery We are now entering the Broadband Era

7. Unicast Content Delivery In the Broadband Era

8. Unicast Content Delivery In the Broadband Era

9. Unicast Content Delivery In the Broadband Era

10. Unicast Content Delivery In the Broadband Era

11. Unicast Content Delivery Current Situation

12. Content Delivery Networks:Content network, caching, delivery from the edge

13. Content Delivery Networks Moving Content to the Edge Directing requests to the Edge

14. Content Delivery Networks Moving Content to the Edge also moves the problem.. to the edge

15. Content Delivery Networks Again, a non scalable solution

16. CDN: Moving Content to the Edge • Requires: • Control, re-direction, update • Overcomes: • Network link congestion • Network equipment congestion • Distance delay • Does NOT solve: • Edge server congestion • Storage problems • Bandwidth utilization

17. What About Multicast??

18. IP Multicast

19. IP Multicast

20. IP Multicast

21. IP Multicast

22. IP Multicast

23. IP Multicast

24. IP Multicast

25. IP Multicast

26. Multicast is Scalable, but… • Does not support browsing / on-demand • Unidirectional “non interactive” protocol • Congestion • Reliability • Not widely deployed • ISP’s worry that the network may crash • Inter-domain connectivity issues • Multiple, complicated, routing protocols

27. Bandwiz Solution Broadband Content Delivery On-Demand over Multicast

28. Coding for asynchronous (on demand) content delivery

29. Features • Negligible receiver overhead (typically < 1%) • Can be achieved with low computational complexity • Encoder is flexible for ‘use optimization’ (file download or browsing) with a universal decoder • Supports content “grouping” and differential decoding

30. But what about Media Streaming? • Basic delivery scheme above requires receiving the entire file prior to display • Streaming solution: Data can be decoded on the fly, enabling streaming-on-demand • Streaming performance defined by: • Bandwidth at the sender • Peak bandwidth at the receiver • Latency • Computational complexity • Latency is reduced exponentially with increased bandwidth at the server

31. Streaming On Demand • Naïve solution – Carousel • Today’s NVoD: • N times bandwidth • 1/N viewing latency • Bandwiz Solution • N times bandwidth • 1/e^N viewing latency!!!

32. Transmitter bandwidth 1 Mbps 1.5 Mbps Receiver peak bandwidth 1 Mbps 320 Kbps CPU utilization ~3% ~1% Latency from ‘click’ to view 50 seconds 45 seconds Streaming - Example • 90 minutes movie • 200 kbps real time bit-rate • total file size of 135 MB

33. Summary: Streaming On-Demand • With ONLY 4 to 7 times the bandwidth of a single unicast transmission, and almost the same receiving bandwidth: • Practically unlimited number of viewers • Full screen quality viewing • Most loss tolerant solution • View from start when joining • Short viewing latency (system parameter)

34. Servers/Bandwidth Savings in both Unicast/Multicast • 2-3 full feature 100 min. MPEG movies • 1 mbps per stream • 1000 simultaneous viewers with broadband modems

35. Summary • Multicast: • Scalable, substantial resource savings • However, unidirectional, non-interactive, same data to all receivers • The Holy Grail: • Use Multicast for On-Demand Delivery of Popular Content • Streaming Solution: • Optimal Tradeoff between Server Bandwidth and Delay

36. THANK YOU