Tech recommends downgrade to ADSL? Unstable VDSL (been installed for over a year)

Forums › New Zealand Broadband › Tech recommends downgrade to ADSL? Unstable VDSL (been installed for over a year)

Killerkiwi2005

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#245054 16-Jan-2019 14:38

We have had our vdsl line for over a year, it was working fine then started dropping off and reconnecting multiple times a day, The chorus tech has stated that we have 2.6km of cable to the exchange and vdsl only works to 1km so we will need to downgrade to adsl.Anybody got any tips or advice here as we get ~36mb down at the moment and I don't really want to go down in speed

RunningMan

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#2162024 16-Jan-2019 14:46

Post your line stats

Ge0rge

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#2162046 16-Jan-2019 15:31

I had to revert last year (or maybe the year before?) and I'm only a 1.9km round trip to the exchange. While my down speeds were significantly faster, the up speeds were so slow that they became saturated and thus ended up limiting the down speed to slower than what I can achieve on adsl.

Ah the joys of living ever-so-slightly rural :)

Killerkiwi2005

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#2162049 16-Jan-2019 15:38

Ge0rge: I had to revert last year (or maybe the year before?) and I'm only a 1.9km round trip to the exchange. While my down speeds were significantly faster, the up speeds were so slow that they became saturated and thus ended up limiting the down speed to slower than what I can achieve on adsl.

Ah the joys of living ever-so-slightly rural :)

:( yeah I'm afraid that's going to be the result... I'm just putting off the inevitable, I did notice that the sticky says don't use a power board so I've switched that around

here's the stats I could find

Connection status:Showtime

Upstream line rate (kbit/s): 9842

Downstream line rate (kbit/s): 35690

Maximum upstream rate (kbit/s): 9274

Maximum downstream rate (kbit/s): 37621

Upstream noise safety coefficient (dB): 4.4

Downstream noise safety coefficient (dB): 7.1

Upstream interleave depth: 0

Downstream interleave depth:0

Line standard: VDSL

Upstream line attenuation (dB): 47.6

Downstream line attenuation (dB): 24.1

Upstream output power (dBmV):7.1

Downstream output power (dBmV):14.4

Downstream interleave depth:None

allio

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#2162053 16-Jan-2019 15:53

Those sync rates aren't far off what I get in central Auckland, 200 metres to the cabinet. I think your upstream is actually higher than mine. Must be a pretty clean (if long) line.

Your modem just seems to have synced very aggressively, pushing past the point of stability. But there is plenty of room to pull back to safe levels and still be far faster than ADSL.

If it keeps dropping, DLM should do its job and pull you back to a slightly more conservative profile with a bit more headroom. How long has it been unstable?

RunningMan

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#2162054 16-Jan-2019 16:00

There looks like a line issue. 24dB downstream attenuation with those sync rates looks fine, except for the 4dB noise margin - lowest should be 6dB on a good line, which suggests something is causing a periodic increase in noise on the line. Line length is certainly a problem for VDSL, but in your case looks OK - something else is the problem.

Killerkiwi2005

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#2162060 16-Jan-2019 16:05

allio:

Those sync rates aren't far off what I get in central Auckland, 200 metres to the cabinet. I think your upstream is actually higher than mine. Must be a pretty clean (if long) line.

Your modem just seems to have synced very aggressively, pushing past the point of stability. But there is plenty of room to pull back to safe levels and still be far faster than ADSL.

If it keeps dropping, DLM should do its job and pull you back to a slightly more conservative profile with a bit more headroom. How long has it been unstable?

About 5 weeks, was fine before that (we were away over Christmas so just left it till we got back)

tripper1000

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#2162068 16-Jan-2019 16:21

Ask a potentially silly question, but since the initial install, has something else been connected to the phone line - like a phone or an alarm, or has the modem been relocated in the premises?

My folks had DSL that was decent when it worked but dropped out multiple times every day and it was an alarm that was hijacking the phone line and killing the DSL(installed a master filter upstream of the alarm to resolve the issue).

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Killerkiwi2005

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#2162069 16-Jan-2019 16:24

tripper1000:

Ask a potentially silly question, but since the initial install, has something else been connected to the phone line - like a phone or an alarm, or has the modem been relocated in the premises?

My folks had DSL that was decent when it worked but dropped out multiple times every day and it was an alarm that was hijacking the phone line and killing the DSL(installed a master filter upstream of the alarm to resolve the issue).

Nope master filter with a single phone line and vdsl modem nothing else has changed

allio

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#2162070 16-Jan-2019 16:26

Killerkiwi2005:

About 5 weeks, was fine before that (we were away over Christmas so just left it till we got back)

Hmm - I'll leave it to one of the several VDSL experts on Geekzone to explain why you'd still be syncing with 4.4/7.1 SNR despite having 5 weeks of instability and plenty of headroom on the line. Seems like the exact situation D-DLM is designed to avoid.

RunningMan

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#2162071 16-Jan-2019 16:30

The 4dB noise margin is because the noise is changing faster than DLM can change, so it's something that is coming and going on the line. Most common would be a dodgy or corroded joint, less likely but possible is some sort of external interference.

What is the internal wiring like?

Killerkiwi2005

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#2162077 16-Jan-2019 16:51

RunningMan:

The 4dB noise margin is because the noise is changing faster than DLM can change, so it's something that is coming and going on the line. Most common would be a dodgy or corroded joint, less likely but possible is some sort of external interference.

What is the internal wiring like?

Old but we have disconnected all jack points except the master when the master filter was installed 12 months ago

RunningMan

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#2162079 16-Jan-2019 16:52

Has your ISP run a line test?

josephhinvest

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#2162084 16-Jan-2019 17:05

I recently went through a similar sounding situation! 2 week outage and 4 visits from Chorus. Eventually established that when equipment was replaced in a cabinet up the road, the cable length to our house was increased so much that VDSL became impossible to sustain a connection.
Was downgraded to ADSL, which works but is slow. Very disappointing outcome. Also it’s slower is no cheaper!

Cheers,
Joseph

Chorusnz

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#2162454 17-Jan-2019 10:35

@Killerkiwi2005 that doesn't sound quite right. I can take a look into that and see if it's accurate if you want to send a private message with your details? ^DR

hio77

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#2162514 17-Jan-2019 12:06

Those stats look totally fine for the distance.

There are valid cases where dropping from vdsl to adsl is a valid solution, but this sounds like too hard bucket...

@ChorusNZ are already offering to have a look here, so they will surely help.

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