[kareemm]

The difference between ESPN and Netflix is that you have (tens of) millions of people watching an event at the exact same time. This is a similar problem in nature, but the simultaneous nature of the problem mean your solution will be different.

[jdavis703]

Doesn't that make the problem easier? Send one stream to a network node close to the viewer and then "fan out" the stream from there? No need to worry about 50 different users who all started watching Luke Cage at slightly different times.

[apendleton]

Yeah, but for non-live broadcasts you can do this too, but do it asynchronously, and indeed, Netflix does. If you're watching reasonably popular content (Luke Cage, say), you're not getting it from Netflix proper, you're getting it from a a Netflix point of presence colocated with your ISP. It's the exact same "fan out" model, but for most of the transit (the whole part that crosses the open Internet) they can take as long as they want, transfer during off-peak periods, are tolerant of congestion, etc.

[lmm]

Multicast has been in the works for decades but it's still not reliable enough. Partly a chicken and egg problem - sysadmins don't bother checking that multicast works on their networks, because no-one uses multicast.

[Pyxl101]

What he's describing doesn't require multicast. It just requires a hub and spoke model with multiple layers.