There is plenty of noise lately about the video on demand being a huge bandwidth burden to cable broadband providers and others. Having worked for a wireless ISP I understand that quite well. End users always thought bandwidth was free for some reason. I was just thinking that almost all major ISP's use web caching to speed up popular websites and save bandwidth. Perhaps by adding some extensions to web caching much of the burden could be reduced. If an say a large ISP in say Detroit has 500+ users listening to the same audio or video stream at the same time it could be buffered and delayed slightly to allow the ISP to only pull one stream off the Internet and serve all 500+ users. Keep alives and such could be exchanged between the orgin and clients to keep statistics and tracking up to date. For movies on demand they could be done in encrypted chunks that are cached rather then one big file. When all or enough chunks are downloaded playback could begin. This would not save much traffic in the last mile or loop but would reduce backbone traffic and perhaps upstream traffic since p2p would not need to be used. Most cable and wireless last mile loops are optimised for downstream rather then upstream anyway. There could be a fallback mechanism if a given cache did not support it as well. Disk space is cheap compared to bandwidth. I remember years ago a single T1 was 1300$ a month. Then each wireless pop only had so much capacity. Things have improved since then but not enormously. Just a though. Matt
