The issue is more Chorus sticking to their 10.8dB maximum attenuation. This is not possible at that distance.
There are people out there who have connections that exceed this limit as installs have happened for a variety of reasons. Most of whom have connections they may feel are OK, but the impact they can have on the network in terms of crosstalk are catastrophic to other xDSL users and for this reason they should never have been provisioned.
VDSL gets around this with UPBO, but it can't fully eliminate the issues of FEXT and NEXT. Users with poor signal quality basically end up impacting users close to the ISAM.
There are people out there who have connections that exceed this limit as installs have happened for a variety of reasons. Most of whom have connections they may feel are OK, but the impact they can have on the network in terms of crosstalk are catastrophic to other xDSL users and for this reason they should never have been provisioned.
VDSL gets around this with UPBO, but it can't fully eliminate the issues of FEXT and NEXT. Users with poor signal quality basically end up impacting users close to the ISAM.