Facetime and Fibre

[#1]

Hi all
I normally get a steady 40-47 Mbps on my Plusnet FTTC service, but as soon as my daughter goes into Facetime on her iPad, the speed drops to anywhere from 1 to 10Mbps, usually around 3. I know that speed will drop as people start to use it, but I thought one of the benefits of fibre was meant to be that everyone in the house could all be doing their own thing on line. But as soon as one person is on Facetime, the connection becomes unusable for anyone else wanting to watch video, use On demand TV etc
Is it normal for the speed to drop from just under 50Mbps to 3Mbps just because of Facetime?
Cheers
Andy

[#2]

It shouldn't really drop by much at all.
Are you all wirelessly connected? How are you testing for the speed/which site?

[#3]

i'd be willing to bet that facetime is flooding the router, thus any other requests hitting the router get bottlenecked.
are you using the supplied plusnet router?

[#4]

Isn't face time a 2-way protocol, with just as much upstream as downstream?
The behaviour you see is reminiscent of the upstream being congested, such that the ACK responses to your download packets aren't going out fast enough, causing the downstream to get throttled by the far-end server.