If too many people watch tv on homechoice will the homechoice servers crash?
What if two many people try to watch the same programme?

Any sane organization would monitor the number of users connected to a particular server & plan for this likelyhood.

So I suspect the answer to your question is no, but that depends on whether HC are sane or not

Eventually, yes, they'd crash.

But probably before then, their pipe to the internet would run out of bandwidth! All the same, they should have enough bandwidth to serve all the users at one time.

Even in this highly hypothetical case, a crash would be a bad thing. The proper response would be a "server busy" notification of some sort. Crashing never is a valid solution.

Does anybody know the maximum percentage of homechoice users that can be watching tv at one time without homechoice's servers crashing?

There should be plenty for all of them (think about Christmas Day, etc.).

As BM corrected me above - the server would notify "server busy" long before it would crash - the boxes probably just try again if they get that, and therefore, even if the servers are too busy, the service seems problemless.

It doesn't matter how many people are watching broadcast TV. Everyone could. What matters is how many are watching VOD. I don't know what the maximum is but I would guess they are increasing it to support their subscriber growth.

Well, yeah, VOD users one stream per person, from the server.

Any ideas exactly how the broadcast TV streams work?

My guess is that Each stream must be sent out at the same time once, then simply "duplicated / split" OR it is just picked up by everyone, rather that thosands of transmittions of the same thing to thousands of people.

Eg, say that every IP packet is not sent to "mr & mrs joe bloggs" individually..., that it is just one universal transmittion that can be picked up by any authorized device on the network (like a terrestial signal, but a IP broadcast).

Well, that is just my ramblings, feel free to correct me if I am wrong.
-Chris

What Chris is describing is called Multicasting.

Basically the Homechoice Network will multicast the broadcast to all it's routers.

Assuming 2 to 3Mbps per broadcast channel this is quite a small amount ob bandwitdth to be providing to each edge router. The edge router then send the requested stream on on demand.

So you can supply tens to hundreds of throusands of people with minimal network overhead.

As they run their own network now I'd imagine that they have some pretty heft backhaul links to the core of their network in the multiple Gigabit range of speeds.

We shouldn't see problems for a while