Lazy Llama
Suburban robots that monitor reality
As well as CDNs which prunus mentions, they use multicast capabilities to reduce bandwidth demand.Interesting post on reddit this morning - I hadn't realized (thought about) that hashed passwords are the same length irrespective of the length of the actual password. Someone in a company's IT wanted to know how long peoples' actual passwords are to ensure they weren't insecure. They weren't allowed to ask because knowing that someone's password is for example 8 characters long greatly reduces the number of tries a hacker would need.
A question I've often wondered: watching BBC sports transmissions you can click backwards and forwards to view different bits that have happened. With ITV you can't do that - what you see is what you get. Anyone know how much more transmission bandwidth you'd need to do that with BBC? It feels like you'd need a different stream for everyone watching but that can't be right - presumably they have a single stream and just point to the point in the recording, but that would also seem to need different transmission streams for each viewer.
There's a reasonable blog post about it on the BBC technology blog: Dynamic Adaptive Streaming over IP Multicast