I am no network expert, but I've dabbled in streaming content over computer networks at work. So I find it interesting to know how the various cable/phone/satellite companies get their digital goodness delivered to my house. Unique solutions, like this AT&T solution, pique my curiosity.
This wikipedia article summarizes the architecture:
Unlike traditional offerings from U.S. cable companies, video is delivered over IP from the head end to the consumer's set-top box. Broadcast channels are distributed via IP multicast, allowing a single stream (channel) to be sent to any number of recipients.
Multicasting rocks. This BBC radio page sums it up pretty well:
It's similar to Broadcast. If you think about your Digital Radio it's tuned into a specific station, it picks up data that has an identifier saying 'this is for the station you want', we just have to put one copy of the station on transmitters. Whereas Unicast is a lot more like us having to call each listener on the phone and play-back the station you request.
In the past I've mentioned to Craig that if my ISPs finally support multicasting to my home, then radio stations, like woxy, wouldn't have to pay a gazillion dollars for their internet bandwidth.
Multicasting isn't without it's share of complexities, of course. The U-verse details came to my attention when Comcast reportedly stated problems with U-verse multicasting traffic spilling out onto their network.
