no worries. We can't all read every post and remember all of those that we do read.

Hi

BT uses GPON, this splits the light in the fibre between up to ~32 other properties. It's completely passive, just using optics to spread the light between everyone else.

This means that everyone on the same fibre receives everyone else's data including their own. That single fibre arriving at your property is flashing away with around 2.5GBps of data, with the ONT only listening to data tagged for you. This is why a second service can be enabled on the same fibre without physically needing another fibre cable, as it's all there anyway.

For security of course data is encrypted and only your ONT can decrypt your data, this is why you can't just randomly switch out your ONT for another one unless BT register it against your account.

Regards

Phil