Apologies, a long post!

We live just outside the official Auckland urban area. We changed from ADSL2+ to VDSL2 in May 2016 shortly after Chorus changed their criteria for connecting VDSL. Prior to the changeover, we were typically getting speeds of ~10+Mbs down and ~1.0 Mbs up on ADSL2+. As part of the new install we got a Vodafone HG659 modem and of course, a new VDSL master splitter installed.  Immediately after the changeover, our down speed had effectively doubled to 22-23 Mbs up but down speed dropped to 0.85 – 0.9 Mbs (as measured on speedtest.net).

With VDSL boost on the horizon, I re-checked 3-4 weeks ago. Down speed was still 22 Mbs but up appeared to have dropped even further to ~0.7 Mbs. Disappointing but I figured we could live with it – hoping that VDSL boost may help.

According to a (second) Chorus tech here 4 days ago (Easter Friday!), it is ~1.6 km cable distance from the cabinet to our house (could be right – I get 1.8km following around streets in Gmaps). The line along the road is an underground trunk (was SH1 until ~8 yrs ago).

The connection from the road to our house consists of ~150m of overhead cable (over the road and across a neighbouring property), then finally ~50m underground to our house. The overhead line is a ~15 pair cable and the final 50m underground, a 3-pair cable. There are potentially connections to 5 rental units on the neighbouring property from the same point (one overhead, 4 underground) though when we had a phone line issue ~3 years ago, none of the residents on the neighbouring property had a landline and only one had broadband. Most of the incoming ~15 pairs at the base of the pole on the neighbouring property are not connected to anything.

About 10 days ago our VDSL connection suddenly failed and ever since has been unusable. Occasionally we get perhaps up to half an hour uptime but much more often it is only a few minutes or seconds, often followed by 30mins – 2+ hours of no connection. Our landline still works, though has always been a bit substandard (voices often muffled).

On Monday last week (~3 days after the connection went down) I phoned Vodafone and a Chorus technician came out on the Wednesday. He was here over 2 hours and checked the connection at the point our modem is connected, the incoming line on the outside wall of the house, at the pole on the neighbouring property where the line changes from overhead to underground, and at the roadside. He told an adult son who was here that he was getting 3Mbs at the road but that dropped to 0.9Mbs at the pole on the neighbouring property. He confirmed the dropouts but was not able to do anything about it.

Initially the technician told my son he saw no point checking with a different modem as he considered the main problem was the overhead line, which he said were always smaller diameter wire than underground cables. Hence the high attenuation between road and the pole on the neighbouring property. However, about 10mins after leaving, the technician phoned me and suggested we should try a different modem as he was able to get a connection with his test modem. Since we still had effectively no connection with the HG659, we went out and bought a new modem (Asus DSL-AC56U), and updated it to latest firmware. Alas, that changed nothing. Still exactly the same behaviour. Have swapped between the two a couple of times but see no difference behaviour.

I followed up with Vodafone. The first technician had closed the ticket. They activated a new incident and a second technician came out on Friday (Easter).  Vodafone also uploaded a data block lasting 7 days onto my mobile so we connect through that.  However, that is not practical as there are three adults in the house, two using desktop PC’s that do not have wireless AP's.  Plus my mobile was getting warm-hot with just a single connection through it. Vodafone eventually provided us with a Vodem with another 7-day data block. A very good service (all credit to Vodafone) but it is not a permanent fix. Only 3 days left on that and there is no fix to our VDSL connection problems in sight.

The second technician got measurements of 0.9Mbs up speed at the pole, 0.5 up where the line comes into the house, and 0.4 Mbs up where our modem is connected.  But again said there was nothing he could do to fix the problem. He did mutter something to the effect that he could report a fault at the road but they are all contractors and if he had to come out again on the same issue, it would be in his own time as they are only paid for a single visit.  Suggested perhaps reverting to ADSL.  He dismissed the notion that the overhead line was an issue as it was a ~15 pair cable.  Replacing it with an underground cable would make no difference (apart from being very expensive, if feasible - not on our property).  He changed the cable pair used over the final 50m of underground cable but that made no difference.

About three minutes after the second technician left, I got a txt from Vodafone say their “tech advises that your fault .. has been investigated and resolved.  Please call .. if the issue .. not resolved”.

Now at a loss as to what is the best long-term solution but will leave that aside for the moment. In periods when the VDSL connection has been up, we have confirmed that we are now getting only 0.4Mbs up and only 9Mbs down.  Both a significant degradation in performance relative to just 3-4 weeks ago.  The Chorus website is still showing our connection as VDSL with a download speed of 22Mbs; ie. same as I measured a month or so ago.

My main questions at this point are:
- Why the sudden degradation in performance?
- The second technician suggested it was probably because of more people switching to VDSL.  But that would not explain the sudden degradation of service? Almost all, if not all new houses near the cabinet are in a new housing area which is on UFB.  No new houses near us.
- Any possibility it is related to implementation of VDSL boost? The timing seems possibly right?
- Are the decreases in upload speed as expected; ie. 3Mbs on the roadside 1.4km from the cabinet, down to 0.9 Mbs a further 150m along an overhead cable, then down to 0.5 Mbs after a further 50m of underground cable?
- Is it possible the ~13 unused pairs in the overhead cable are increasing the attenuation? Inductance?
- Would it help/be permissible to connect the three pairs of the underground cable to three of the overhead cable pairs & join the wires together at each end (ie. road and house) to triple the cross section area of copper between the road and house?  No way that more than 6 of the ~15 pairs will be used in the next 20-30 years.

The Chorus Broadband map shows us within the 20Mbs+ zone. That zone extends in a strip ~700m further along the road from where we connect. Almost all the download speed vs distance charts I looked at show VSDL having higher download speeds than ADSL2+ out to about 2km, which is consistent with the Chorus Broadband map.

The first technician commented at one point that there had been problems with the main cable along the road but made no further mention of it.

Cannot provide connection stats as we cannot connect on VDSL at the moment. For the last few days have solely used the wireless connection.

I will follow up with Vodafone again later today but from our experience to date I am not certain what more they can do?