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VDSL's slow - is it the filter? what can we try next?

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Posts: 77
Registered: ‎17-10-2008
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VDSL's slow - is it the filter? what can we try next?

by Contributor Kelly Contributor
Message 1 of 19 (8,584 Views)

I got VDSL installed on 24 February. It's pretty slow - my download speed is 17 Mbps. The next day, I wrote in these forums about my frustration with the speed and my take on the installation I experienced. Thanks to johnr and TimA who replied at the time.

 

Here are my stats today:

DSL synchronization status:   Up

Connection status:                 Showtime

Upstream line rate (kbit/s):      5611

Downstream line rate (kbit/s): 18254

Maximum upstream rate (kbit/s):     5709

Maximum downstream rate (kbit/s): 17680

Upstream noise safety coefficient (dB):      12

Downstream noise safety coefficient (dB): 11.6

Upstream interleave depth:     0

Downstream interleave depth: 0

Line standard:      VDSL

Upstream line attenuation (dB):        0

Downstream line attenuation (dB):   0

Upstream output power (dBmV):     8.2

Downstream output power (dBmV):          18.5

Downstream interleave depth: None

 

In a series of PMs, TimA said that I am running off an exchange which I am about 700-800 m away from. He suggested that my attenuation was pretty high:

You are running off exchange VDSL, Stats show that its generally slower, You have a high attenuation for VDSL:
lqd.parameter.loop.attenuation 48.6(UP) 24.6(DOWN)
You can either roll back to ADSL or keep it as is for the year where its at the same value then roll back. Your choice.

 

I've questioned whether my existing whole-house filter is a problem; it was installed in appx 2008. The Chorus technician that did my VDSL install heard that I had the existing filter and didn't even look at it, just switched my jack point from BT to RJ45 format, plugged in the modem, tested, and left. TimA suggested that my existing filter might be ADSL-only. How is that possible? I thought the point of the filter was to separate the wire strands etc, and that the data signal would be entirely unaffected by this process.

 

So my questions are:

1) Now that my 10-day attenuation period is long over, can my line please be tested in more detail to see what the problem is with the VSDL speed?

 

2) Is that existing filter really likely to be a problem? If so, can a tech come out again and do a proper job of checking my site and installing the correct filter, since this wasn't done correctly on the first visit?

 

3) Is there anything else I can/should try here? I'm pretty disappointed with the VDSL service so far, since it's basically no different than my ADSL service was. Is there any reason to stick with VDSL if there isn't any improvement (i.e. if the tests aren't conclusive and the filter isn't the problem)?


Accepted Solutions
Staff Lon
Staff
Posts: 1,305
Registered: ‎01-03-2012

Re: VDSL's slow - is it the filter? what can we try next?

by Staff Lon Staff
Message 8 of 19 (12,481 Views)

Line test results are back, and they're looking decent (I got a second and third opinion from @Nigelhu and @TimA just to be on the safe side!).

 

As @coffeebaron pointed out you're likely to be on the lower end for VDSL. This is unfortunately he case here but the line does seem to be performing to spec. The results are consistent with your surrounding neighbours which I also tested - the maximum speed on VDSL we would be able to achieve on your current line is approximate 18Mbps with absolutely perfect conditions.

 

I can understand that this might be a tad disappointing as it doesn't match the expectation you may have had for VDSL. However, VDSL is the fastest kind of connection at your present address until around 2016 with the UFB rollouts.

 

Of course, it is completely up to you to decide whether you wish to remain on VDSL or migrate back to the Red Network. Personally, I would definitely recommend remaining on VDSL until UFB becomes available in your area. Sorry the news isn't better but I hope this clarifies things a bit.

 

Please let me know if you have any further questions. Smiley Happy
Lon

Please note that I am no longer a permanent moderator of this forum and only check messages during my free time.

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Solution
Accepted by topic author Kelly
‎03-10-2015 04:33 AM

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Contributor
Posts: 77
Registered: ‎17-10-2008

Re: VDSL's slow - is it the filter? what can we try next?

by Contributor Kelly Contributor
Message 2 of 19 (8,533 Views)

Welcome back from our long holidays, everyone. Can someone from VFNZ comment on my queries please? Thank you!

Retired Staff
Posts: 3,380
Registered: ‎21-08-2010

Re: VDSL's slow - is it the filter? what can we try next?

by Retired Staff Dylan Retired Staff
Message 3 of 19 (8,524 Views)

Hi @Kelly 

 

Sorry for the delay responding, I'll need to look into this in more detail but one of our systems is unavailable to me at the moment, hopefully won't be long!

 

Looking at the stats above the upload speed is a great improvement over ADSL. I understand in some locations VDSL might be technically available but ADSL could provide a better experience, the signals operate differently over distance.

 

I'll be in touch with more info later on today.

 

Cheers

 

Dylan

Staff Lon
Staff
Posts: 1,305
Registered: ‎01-03-2012

Re: VDSL's slow - is it the filter? what can we try next?

by Staff Lon Staff
Message 4 of 19 (8,517 Views)

Hi @Kelly - I'm having a look at your line right now. I can't see any obvious issues, but I'm running a 2 hour analyzer so I can see if we have any glaring abnormalities to be concerned about.

 

Just out of curiosity, can you recall what kind of speeds you were getting before we moved you from our Red Network onto VDSL?

Please note that I am no longer a permanent moderator of this forum and only check messages during my free time.
Contributor
Posts: 77
Registered: ‎17-10-2008

Re: VDSL's slow - is it the filter? what can we try next?

by Contributor Kelly Contributor
Message 5 of 19 (8,514 Views)

Thanks for getting the analyser started, @Lon! I'll be glad to see what it comes up with.

 

In my Red ADSL days, I was getting around 15 Mbps download and 1 Mbps upload speeds, so @Dylan is correct that my upload speed has increased appx five-fold, but there's no real difference in my download speed.

 

I have done a bit of reading in Geekzone today and it seems as though the central line filters are all the same, so I wouldn't expect that to be causing the problem - but given that I see new ones are about $40, I can easily swap this out if there is any suspicion that doing so might raise my download speeds. I suppose I'd be both faster and cheaper at doing this than a tech, though I'm still disappointed that this wasn't checked at all at the time of my VDSL installation.

Retired Staff
Posts: 3,380
Registered: ‎21-08-2010

Re: VDSL's slow - is it the filter? what can we try next?

by Retired Staff Dylan Retired Staff
Message 6 of 19 (8,509 Views)

Hi @Kelly 

 

I understand the ADSL splitters have two pairs of wires and the VDSL splitters have three pairs of wires. There's some pictures of two types in this geekzone thread: http://www.geekzone.co.nz/forums.asp?forumid=49&topicid=136451

 

Honestly I don't know if that's true for absolutely every filter. Folks like @coffeebaron know much more about this than I do! Smiley Happy

 

I would like to get the tech out again to look into it but we need to be able to show a reason for that. Hopefully the checks Lon is running will help with that.

 

Cheers

 

Dylan

 

Senior Contributor
Posts: 360
Registered: ‎24-08-2008

Re: VDSL's slow - is it the filter? what can we try next?

by Senior Contributor coffeebaron Senior Contributor
Message 7 of 19 (8,497 Views)

There is a difference between ADSL rated and VDSL rated master filters. Due to the higher frequencies used for VDSL, you can end up with some frequency "leak" across to the POTS side if using an ADSL rated filter. This would be more apparent on a clothed VDSL connection. For example I replaced and old ADSL rated filter recently on a naked-VDSL connection, and this did not really gain anything. I suspect there would have been some gain if they were on a clothed connection.

 

The other factor here is that ADSL is less fussy, so existing wiring may have been utilised when the ADSL filter was installed. This wiring which would have been fine for ADSL, may not be so good for VDSL.

 

Also based on your previous 15Mbps, and if this was Red network, then this would put you at the lessor end for VDSL.

Staff Lon
Staff
Posts: 1,305
Registered: ‎01-03-2012

Re: VDSL's slow - is it the filter? what can we try next?

by Staff Lon Staff
Message 8 of 19 (12,482 Views)

Line test results are back, and they're looking decent (I got a second and third opinion from @Nigelhu and @TimA just to be on the safe side!).

 

As @coffeebaron pointed out you're likely to be on the lower end for VDSL. This is unfortunately he case here but the line does seem to be performing to spec. The results are consistent with your surrounding neighbours which I also tested - the maximum speed on VDSL we would be able to achieve on your current line is approximate 18Mbps with absolutely perfect conditions.

 

I can understand that this might be a tad disappointing as it doesn't match the expectation you may have had for VDSL. However, VDSL is the fastest kind of connection at your present address until around 2016 with the UFB rollouts.

 

Of course, it is completely up to you to decide whether you wish to remain on VDSL or migrate back to the Red Network. Personally, I would definitely recommend remaining on VDSL until UFB becomes available in your area. Sorry the news isn't better but I hope this clarifies things a bit.

 

Please let me know if you have any further questions. Smiley Happy
Lon

Please note that I am no longer a permanent moderator of this forum and only check messages during my free time.
Solution
Accepted by topic author Kelly
‎03-10-2015 04:33 AM
Senior Contributor
Posts: 447
Registered: ‎07-08-2008

Re: VDSL's slow - is it the filter? what can we try next?

by Senior Contributor shadow Senior Contributor
Message 9 of 19 (8,469 Views)

Is it true that if you reboot your VDSL router a few times in a row it kicks off DLM?

I've noticed our VDSL has slowed down a bit also, nothing overly dramatic (5mb slower and 20ms more ping), hasn't slowed enough yet where I'd ring the helpdesk wanting answers

Ninja Master
Posts: 20,516
Registered: ‎06-08-2008

Re: VDSL's slow - is it the filter? what can we try next?

by Ninja Master Ninja Master Ninja Master
Message 10 of 19 (8,461 Views)

Slow down could also be related to cross talk which increases as more subscribers move to VDSL

Ex VodafoneNZ staff member 17 years 4 days
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