Can VDSL run on one wire ?

Forums › New Zealand Broadband › Can VDSL run on one wire ?

Mark

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#228554 11-Jan-2018 11:56

Just had a fault fixed on my VDSL line ... was getting 70/30 speeds, then the storm knocked out the local cabinets and after Chorus fixed that I was back online at 18/9, not so nice I thought, so got a fault logged and let 2Degrees do al their testing stuff to no avail so I asked them to log a Chorus job yesterday.

The Chorus guy arrived this morning (nice and quick!), plugged his widgets in and couldn't get a tone signal at all .. walked off to the grey mushroom thing with the wires in it and found one wire completely snapped, joined it back up and back to 70/30 again!

Both of us puzzled as to how I was even getting any internet at all!

So can VDSL sync up with only a single wire ?

Coil

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#1936142 11-Jan-2018 12:01

Single wire being a single core? Google seems to have mixed results.
Was probably just a wet cable or join.

Some techs are quite imaginative with fault descriptions.

Jase2985

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#1936144 11-Jan-2018 12:08

https://www.geekzone.co.nz/forums.asp?forumid=39&topicid=227495

chevrolux

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#1936146 11-Jan-2018 12:09

Yea absolutely possible. Just with seriously degraded performance. Probably wasn't fully broken but dead close to being broken that a strong breeze would of broken it.

Yet another reason to get on to fibre the moment it is available. I suspect come 2020 the response to fixing that fault will be, fibre is available, upgrade to it.

phantomdb

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#1936151 11-Jan-2018 12:13

I can vouch for a single wire VDSL connection. Have seen and actually fixed the issue myself.

The speed difference is huge

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hoane

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#1936152 11-Jan-2018 12:17

Amazing as it seems, DSL can work on one wire, but not very well as you have experienced.

My DSL at my new house was rubbish so I got Chorus to investigate. Turned out that the internal wiring from the ETP to Master jack was incorrect - Orange & White wire at ETP and Yellow & White wire at Master jackpoint. Despite only one "leg" of the circuit being connected, the interwebs continued (albeit rather lethargically) to flow.

If there had been a PSTN service on the landline it would have been obvious due to lack of dialtone.

DSL is not as straight-forward as you might think - it can be "working" but not connected correctly.

This is a big issue when ISP helpdesks will check if you can get a webpage to load - then tell you your problem "is most likely due to network congestion".

Wiring faults in buildings are a large contributor to poor internet experience.

Mistenfuru

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#1936154 11-Jan-2018 12:20

Yep, Single side disconnect is a common DSL/Phone fault, results in degraded DSL sync and no dialtone.

From an ISP perspective we commonly see this reflected in a halved Upload or Download rate on ADSL (VDSL can be significantly worse)

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Mark

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#1936208 11-Jan-2018 13:13

Thanks .. was puzzling as it didn't seem right that it could just sort of work :-)

pillmonsta

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#1937451 12-Jan-2018 03:37

Yes def possible, although sync rates will likely halve...

Lastman

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#1937452 12-Jan-2018 04:59

I had a similar experience where the phone was dead but adsl working, due to a bad connection.

I wondered if the poor connection was simply acting like a capacitor (high pass filter) and/or there was an earth return loop?

Behodar

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#1937474 12-Jan-2018 07:43

*adds to the chorus*

Yep, back in the old days it caused my 12 Mb/s ADSL2 to drop to 1.5 Mb/s. I then had to argue with TelstraClear for a week because they refused to acknowledge that there was a problem, but eventually sent a tech out who fixed it in 5 minutes.

Aredwood

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#1937669 12-Jan-2018 13:14

Lastman: I had a similar experience where the phone was dead but adsl working, due to a bad connection.

I wondered if the poor connection was simply acting like a capacitor (high pass filter) and/or there was an earth return loop?

My understanding is that DSL is simply high frequency AC. So even stray capacitance between the broken leg and another leg from an unrelated pair, or even the mass of earth. Can still allow enough signal through to allow the connection to partly work.

I had fun with a fault on my underground leadin awhile ago. Phone would keep failing and ADSL would get really slow. The usual 48V idle voltage would drop as low as 2.5V, but the ADSL managed to work through that. Telecom had to visit approx 10 times, until it was traced to the 2 legs in the cable intermittently shorting together. The technician said it is unusual for that to happen without also having leakage to earth.

Getting fibre installed from scratch was far easier to deal with.