That's interesting. This is my situation.  Two sets of phone lines come into the house - existing pair which was Telecom's which the previous owner used and a new pair that TCL provisioned.

Both pairs are provisioned in the house since I have a second phone line.

I want Naked DSL since I don't want yet to switch my phones over to TNZ.

So what I would like is the following

1. Some ISP can get into the cabinet and connect up my TNZ copper to it.
2. I disconnect my second phone line and get the installer to connect the TZN copper coming to the house to the second pair that goes into the house (only exits at two points).
3. They provision the DSL on that pair and given I will probably ditch the second phone line, I don't need a filter anywhere.

I did call Orcon but as usual their CSR were not that clued up. They couldn't find my number (not surprising since it's TCL) and said even though there might be cabinets in the street, they could not provide me service directly since I presume they have no colo gear in the cabinet. So they would have to buy from TNZ wholesale.

The situation might also apply to other ISP's but I suppose I would have to call them individually. I did like Orcon's Purple plan which is $39.95 for 1G and then $80 more for 100GB. But I think they are rates when they are colocating and if wholesaling Telecom there's an additional charge.