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Can Plusnet fix my profile to 6 db

DavCee
Newbie
Posts: 6
Registered: ‎06-05-2013

Can Plusnet fix my profile to 6 db

Plusnet ADSL broadband.
Moved from BE broadband to Plusnet last week having already moved a number of my friends/ family from BE to PNet... We all moved because of the Sky takeover.
Initial connection was very similar to BE, on a 6 db profile with download sync about 8000 Kbps. Upload was much slower. After a few days I asked for upload to be uncapped, this was done and greatly increased my upload sync speed.
However the Plusnet system decided to increase my download sync to 8400 Kbps with about a 5.9 db noise margin. Past experience has shown this sync speed was unreliable.
After a few days the Plusnet system seemed to lock me into a 9db profile with a reduced sync speed.... about 7400 Kbps.
Can anyone advise if the Plusnet system can fix my profile to 6 db ?
... For many years I have had a stable 6 db giving a sync of about 8000 Kbps.
Thank you
15 REPLIES 15
Community Veteran
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Registered: ‎10-06-2010

Re: Can Plusnet fix my profile to 6 db

The 8400 kbps with the 5.9 db noise margin probably did have a target noise margin of 6 db.
Superuser
Superuser
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Registered: ‎06-04-2007

Re: Can Plusnet fix my profile to 6 db

Wondering what you meant by "unreliable"? Lots of CRC errors? Is interleaving on or off?
Your connection is probably in its 10-day training period at the moment when the DLM can be more active. Changing settings at this time is generally not favoured.
David
Community Veteran
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Registered: ‎31-08-2007

Re: Can Plusnet fix my profile to 6 db

Can you post up the full DSL stats there DavCee?
Community Veteran
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Re: Can Plusnet fix my profile to 6 db

Just to clarify, the 'Plusnet System' is the BT one used by all ISPs that do not install their own equipment in the telephone exchange.  This targets a noise margin when the connection is established but there is no dynamic control thereafter.  The target is set in 3dB increments and the default initial value is 6dB.  So you would have started out on a target noise margin of 6dB and got 'about 8000kbps'.  But the SNRM reported by your router will vary; there tends to be more noise at night so the SNRM goes down and if the connection is dropped and re-established at night then you may get a somewhat slower download speed.  If you are now getting 8400 kbps download then perhaps the connection was re-established in the middle of the day and just after you had received an incoming phone call, the most propitious conditions for maximum download speed.  If 8400 kbps is not sustainable then it won't be sustained; no need for Plusnet to intervene.
There is a program called Routerstats (or Routerstats Lite) that continually polls your router and which you can use to see how your SNRM varies over time.  You might find that useful to shed light on what is happening.  But please also post your stats. as Anotherone requested. 
Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: ‎13-07-2012

Re: Can Plusnet fix my profile to 6 db

Hi there,
It's certainly better if we can find what is causing the SNR to change, I've checked over your line and cannot see any current issues.
Does your phone line have any interference/noise?
DavCee
Newbie
Posts: 6
Registered: ‎06-05-2013

Re: Can Plusnet fix my profile to 6 db

Chris,
Thank you for your reply.
No problems with my line, quiet line test done.
With BE I was on a 6db profile syncing about 8000 kbps. For many years with BE I had a very stable connection upto the day before I transferred to PlusNet.
I am using the same modem as was used with BE... Netgear DGND3700 v2.  So no wiring or equipment change at my end.
Filter used..... ADSL Nation XTF-68/85 , no internal extensions.
Initially Plusnet sync was the same as BE, but after having the upload cap removed your system tried to sync my line to about 8400 kbps.
Past experience has shown this is a unreliable speed on my line.... too many errors.
After a couple of days this resulted in the sync speed dropping and my profile being set to 9 db.
Rebooting the router has no effect.
Your CS(Josh) has placed an order to reset my line, this should happen by about 19:00 today.
I am not sure how effective this will be as your(BT) system seems to drop the line speed if there is a problem, it then seems to lock the line to the new lower speed profile.
With BE it would very occasionally drop sync speed, but this could be reset my rebooting the router. ... The line would revert to a 6 db profile.
It should be noted even at this lower sync speed I have an exceptionally high sync for the distance I am from the exchange.

Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: ‎13-07-2012

Re: Can Plusnet fix my profile to 6 db

It looks like the reset Josh placed failed due to your line being in the initial 10 day training period.
I have contacted our suppliers and requested that your downstream profile be changed to 6dB, this will take affect in the next few hours.
We just need to monitor your connection over the next few days while your line is in it's training period and we'll go from there.
Community Veteran
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Registered: ‎31-08-2007

Re: Can Plusnet fix my profile to 6 db

Hi DavCee,
Just FYI, the BT Exchange DLM doesn't drop the sync speed, it raises the Target SNRM which has the effect of reducing the sync speed, if it sees too many errors or drops in connection - be wary about multiple modem/router reboots!  In severe cases DLM can Band a connection to a lower speed.
In case you ever have several configuration changes you want to do to a modem/router, go offline and do them.
In fact the safest way if you want to do anything that involves loss of sync, use the following Disconnect method -
Log in to the Modem/Router, click Disconnect to drop the PPP Internet session (this is not the sync), wait about a minute and then power down the Modem/Router. After about another minute you can unplug it from the line. Do whatever is needed, but stay offline for at least 10 minutes. When you re-connect and power up, Login to the Modem/Router and click Connect. Don't do this more than 5 times in an hour, then leave it for the rest of the day. This method is to help stop the Exchange DLM from thinking your sync loss was a dropped connection.
PS. You can do a Disconnect & Connect (without a power down) to Gateway hop (as frequently as you wish).
As Chris has said they are going to get your DS SNRM set at 6dB, the above may not be as critical. HTH.
DavCee
Newbie
Posts: 6
Registered: ‎06-05-2013

Re: Can Plusnet fix my profile to 6 db

Anotherone,
Thank you for the useful information.
I had guessed the BT system was increasing the target SNRM. It seems it's a one way effect only.... with BE it would do the same but on modem reboot it would revert to the 6 db profile.
Hopefully Chris can get the SNRM set at 6 db, this would possibly have my connection operating similar to BE.
It would also remove another problem I have.... I have a lot of energy saving features in my home, one being the automatic turnoff of unused equipment. My modem is turned off if not used/ required. This has been disabled since connecting to Plusnet as I was unsure of the effect it would have.
I would never have left BE but for the Sky takover... their customer service was great.
However since joining Plusnet I have found their CS first class... Moved three other friends/family with only one problem... exchange fault, Plusnet CS resolved the problem with no fuss.

Chris,
Many thanks for your help too.
DavCee
Newbie
Posts: 6
Registered: ‎06-05-2013

Re: Can Plusnet fix my profile to 6 db

Chris,
Quick update....
Link Rate       8167 Kbps 888 Kbps
Line Attenuation  45.5 dB   24.3 dB
Noise Margin     5.8 dB     10.3 dB
Bit higher than my usual... noise margin drops a bit in the evening
Community Veteran
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Registered: ‎31-08-2007

Re: Can Plusnet fix my profile to 6 db

That's pretty good for that attenuation  Wink
BE's DLM does operate differently and you are wise to stop your modem turning off on BT kit especially with your attenuation and SNRM dropping in the evening. How much does it drop by usually?
BT DLM would lower the Target SNRM again if it saw a low error stable line, but this can take weeks!
DavCee
Newbie
Posts: 6
Registered: ‎06-05-2013

Re: Can Plusnet fix my profile to 6 db

Yes... a little bit too good !
Current stats....
Link Rate 8167 Kbps 888 Kbps
Line Attenuation 45.5 dB 24.3 dB
Noise Margin 6.1 dB 10.2 dB
This line I have to the exchange (have had it for many years now after some major line problems) is a bit odd
Some times in the evening it can increase to about 6.5 db or drop to about 5 db.
It can tend to drop to around 5db around 11:00 to 12:00.
Early morning it can reach about 9 db !
Making telephone calls have no effect on Noise Margin
When I had a major line problem many years ago, after a number of engineers tried to fix  the problem, I was lucky to have a very knowledgeable engineer resolve it.
He spent some time detecting and fixing..... There are many paper covered alloy telephone cables in our area, all require replacement.... deadly for data attenuation.
Can only guess he has my line on a good old copper cable.
With distance I am from the exchange should only achieve about a 3000 kbps sync.
..... Fibre will never come to my area
Community Veteran
Posts: 19,106
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Registered: ‎31-08-2007

Re: Can Plusnet fix my profile to 6 db

Aluminium cable, oh yes, when the damp gets into that, it's a right off.
Anyway with that attenuation you should get around 7Mbps on an average line on 21CN so it's obviously a good one, lucky you had a decent engineer. At least you have 21CN  Roll_eyes
Anyway if your margin doesn't drop any lower than 5dB you should be OK unless you are getting shed loads of errors, so let's hope it's fine.
goldenfibre
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Re: Can Plusnet fix my profile to 6 db

Quote from: Anotherone
That's pretty good for that attenuation  Wink
BE's DLM does operate differently and you are wise to stop your modem turning off on BT kit especially with your attenuation and SNRM dropping in the evening. How much does it drop by usually?
BT DLM would lower the Target SNRM again if it saw a low error stable line, but this can take weeks!

Yes that is correct BT DLM had lower my SNR to 1dB from Plusnet reset my SNR of 6dB as the exchange force my snr down to 1dB because it stable for 5 days and only 3 errors (CRC) in the last 5 days.