Profile that has been set and/or in house wiring

many reasons this could be.

Profile (even more important with ddDLM being per line adjusted)

Line condition

Pair condition

Connected CT

MDF layouts

Modem, Chipset Firmware

Time of resync, Noise when resync occurred

list goes on...

Why does the bread land butter side down?
We will never know. Same goes for you question. 
Might be a good assignment for the AUT Physics department!

do you use the same pair of copper wires back to the cabinet / exchange? your pair could just be of poorer condition than theirs

wow, I never got upto half your speed on VDSL, I just upgraded to Fibre30 and get slightly lower than you are getting. 

kinsten:

 

wow, I never got upto half your speed on VDSL, I just upgraded to Fibre30 and get slightly lower than you are getting. 

 

You may find it hard to believe but VDSL as a technology can perform very well (matching fibre in rare cases) if the stars are lining up. The key is IF all the stars are lining up (ie. all factors are good such as distance to cabinet, in house wiring, no interference ..etc).

In real world though, it is very difficult to find find cases where all the stars are lining up for VDSL to excel. Nevertheless, as a stepping stone / transition technology, VDSL is pretty good.

For me it was blamed on multiples and they wouldnt do anything about it, so I get 15ish less then neighbours do.

Have a new leadin to the house and straight from there to rj45 socket on the black 2 pair cable, old connection which went thru the same cables was always much worse, but I found when a chorus tech was here fixing stuff last time and they had the POE open, that in the past the cable to the routers was also in parallel with an old black rope like cable going off "somewhere" that I have no idea where it went. That connection was always much slower than the other.

Old flatmate had a seperate lead in and constnatly had higher speeds than me till one day it went faulty and slow. Then he got charged heaps by chorus for no fault found so I dont really want to bother them unless the connection has actually crapped out, which is about a twice yearly occurance recently.