"I thought that fibre BB was necessary to receive DV usind SH2 via the green socket on the back of it. How can DV come over my existing ADSL system?"
DV can work perfectly well over ANY broadband connection - Full fibre (FTTP), part fibre VDSL (FTTC) and even ADSL. The bandwidth needed by DV is very small so even a slow ADSL broadband will carry it without problems.
BT's publicity confuses the issue by persistently linking DV with "retiring the copper phone service". This just isn't the case.
