Hi tech101,
re: "a video stream of 500 kbps bandwidth can offer video quality comparable or even better than broadcasting and VCR. So for 200 users, a 100 mbps can handle the load even if EVERY user is watching at the same time. Usually, for that kind of capacity, you can at least handle 1000 users - assuming 20% of the users may watch the programs simultaneously."
Acknowledging that there is no single approach, and many different forms of video transport system architectures exist today, and assuming your area of bandwidth focus is in the transport channel and not in server switching speed, then multicasting could be used in most modern IP m-m delivery systems to satisfy same-content distribution to multiple end points.
Thus, for 200 users, all or whom were watching the same title, not nearly as much bandwidth would be required where content to any one of them is delivered satisfactorily at 500 kbps.
The aggregate speed would be more like 1 Mb/s, given the need for bandwidth headroom for bursting and other, miscellaneous signalling occurrences.
Of course, any realistic system would need to deliver more than just a single title of content to all users simultaneously, regardless of how many users there were, so the transport bandwidth requirement would be higher, accordingly, and would also take into account the statistical product of all special features such as VoD unicasting and playback controls.
FAC |
