This is pretty tough since I don't know anything about NZ DSL implementations. There will I am sure be lots of terminology problems.
For
ANY DSL problem always check the phone carefully. In UK at least they don't have to "fix" the DSL ever but they have to fix the phone PDQ. If there is anything to complain about on the phone do so. Noise, clicks, ... This will sometimes fix the DSL too:-) Use the dumbest phone you can find. I used to keep an old cheap phone handy for just this purpose. Check both sides of the calls. Ideally in person.
Unless you have what we call Fibre To The Cabinet (FTTC) the distance to the cab is irrelevant, it's the distance to the exchange that matters.
According to
https://www.increasebroadbandspeed.c...ersus-distance you would expect about that speed 5km plus from the exchange.
Get the stats out of the router/modem, Paste them all here.
Paste everything you see. More is better. Every router model is different on how it presents this information but as far as I know they all have it.
e.g.
Current DSL Connection:
................ Down ..... Up
Rate: 16257 kbs 1164 kbs
Max Rate: 16257 kbs 1164 kbs
Noise Margin: 11.6 dB 6.1 dB
Attenuation: 6.0 dB 2.2 dB
Output Power: 13.7 dBm 10.8 dBm
Protocol: G.DMT2+ Annex A
Channel: Fast
DSLAM Vendor Information Country: {46336} Vendor: {IFTN} Specific: {47473 }
ATM PVC: 0/38
Edited to add:
Also get error counters and packet counters. They can be labelled CRC, FEC, Reed-Solomon EC, BER.
Here are some further examples:
Noise Margin: 8.0 dB 9.5 dB
Output Power: 19.0 dBm 12.0 dBm
Attenuation: 37.0 dB 33.0 dB
DS Channel1 DS Channel0 US Channel1 US Channel0
Speed (kbps): 0 5656 0 243
Cells: 0 0 0 707896
Reed-Solomon EC: 0 49 0 0
CRC Errors: 0 2 0 0
Header Errors: 0 2 0 0
Total BER: 0E-0 4103E-10
Leakage Average BER: 0E-0 4103E-10
Interleave Delay: 0 34 0 15
###
Upstream line rate (kbit/s) 988
Downstream line rate (kbit/s) 15963
Line standard ADSL2+
Channel type Interleaved
Upstream SNR (dB) 9.9
Downstream SNR (dB) 7.9
Upstream interleave depth 1
Downstream interleave depth 64
Upstream line attenuation (dB) 7.4
Downstream line attenuation (dB) 14
Upstream output power (dBmV) 10.5
Downstream output power (dBmV) 0
Upstream CRC 7535
Downstream CRC 0
Upstream FEC 9196
Downstream FEC 0