@Follydude
Regarding something you wrote a while back
>If I had thought it through, ADSL is over ATM, and VDSL is over IP. I assume that FTTC cabinet is IP only?
As you know IP is used across the entire internet. But what you wrote is mixing different communication layers up. When you are using FTCC/VDSL2, over the copper wire from your house to the cab, instead of ATM, which is gone, consigned to history, you use something called PTM. IP is not relevant. So the contrast you were looking for is between ATM and PTM. On the fibre optic link from the cab upstream to the guts of BT, ethernet is used.