Is Multicast the Future of TV?
Cringely thinks so. He explains why in the I, Cringely posting The Once and Future King: Multicast looks to (finally) be the future of television.
IP Multicast is the not-so-simple carriage of the same digital signal to thousands or millions of people at the same time. This is as opposed to unicast, which can also serve millions of people but requires millions of parallel video streams to do so. Multicast was built into the structure of the Internet from the very beginning but was generally not turned on because net admins hate it as a resource hog. But one man’s resource hog is another man’s chance to sell a lot of new equipment, so Cisco has long been a huge supporter of multicast because it requires ever bigger and more powerful routers to implement. Years ago Cisco bought Judy Estrin’s Precept Software and its IPTV product primarily to have an application that would drive the adoption of multicast in the enterprise and beyond. Only that didn’t happen because net admins weren’t giving in, there was no YouTube, and the x386 computers of the era really weren’t capable of handling much video anyway.
See, multicast IS a resource hog.
But to more and more ISPs multicast is looking like the best answer to a huge bandwidth problem, while also being a sneaky way to take back control of the Internet.
Both Comcast and Verizon are rapidly rolling out IP multicast, as I am sure most big cable and telephone ISPs are. Even Verizon’s fiber-to-the-home service, FiOS, is moving to multicast because it was architected in a dumb way that sorely limits what should be a lot of throughput.
There are only two ways for today’s ISPs to carry tomorrow’s Internet video traffic. They can embrace wide-open P2P or they can implement IP Multicast.
Cringely makes a case for IP Multicast in the article. If experience is any indicator, I don’t think the Comcasts and Verizons of the world get the IP TV thing yet.
…John
