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Is Noise Margin manual override possible?

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markr77
Grafter
Posts: 30
Fixes: 2
Registered: ‎16-02-2012

Is Noise Margin manual override possible?

Hi Plusnet,

My connection is dropping every day or 2 and has been for months. Engineer visit found no faults. It used to me up for months.

I noticed the other day that when the noise margin was 7.3dB the connection was stable for 7 days. After a router reboot it went back to 3dB and now disconnects every day or 2.

The current margin is around 3.5dB (syncing at 73Mbps). When the margin was 7.3dB the line appeared more stable and the sync was around 54Mbps I think.

Is it possible to manually raise the lower noise margin threshold? I can forego some speed if stability improved.

I appreciate a drop every day or 2 does not constitute 'a problem' by your definition (3 or more drops in 24hrs OR 6 or more in 72hrs), but when working from home on video calls it's not really workable.

Re. Question #208569319 which has been open since November but not really making progress.

Many thanks,
Mark



20 REPLIES 20
RichardB
All Star
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Registered: ‎19-11-2008

Re: Is Noise Margin manual override possible?

Hi @markr77

Openreach have three DLM stability levels which trade speed against stability.
https://kitz.co.uk/adsl/DLM.htm#dlm_stability_level

Plusnet default to the fastest speed profile.
So yes it is possible to trade some speed for stability.
The difficulty will be in gett8ng a change actioned by PN.
I doubt most of the front line support would be aware of the different Openreach profiles.

Perhaps a polite DM to @Gandalf would work?
Regards
Richard
markr77
Grafter
Posts: 30
Fixes: 2
Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

Customer services did request a change to my stability profile last week, from speed to standard, which they say should have gone through. Unfortunately I don't seem to have a way of knowing if it has actually been changed. SNR margin in router stats hasn't changed much and line still disconnects. Looks like one disconnect every day wouldn't effect the DLM anyway from that link.
Gandalf
Plusnet Help Team
Plusnet Help Team
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Registered: ‎21-04-2017

Re: Is Noise Margin manual override possible?

Thanks for your post @markr77 

I can confirm you're on the Standard stability profile (*More accurately "Stable") as of the 5th January. As there's been no noticeable change, I've increased this further to the Super Stable profile which should start to take effect as of tomorrow but it generally can take 7-14 days for DLM to gradually apply the change.

Fingers crossed this sorts as I can't see there being much more we can do bar sending another engineer to investigate further although with the number of drops within tolerance, there may not be anything they'll be able to do.

*For the sake of clarity as it may cause confusion down the line, BT's terminology of the profiles are Standard, Stable and Super Stable, which are the equivalent of Openreach's Speed, Standard and Stable. 

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
markr77
Grafter
Posts: 30
Fixes: 2
Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

Hi @Gandalf,

No, that's not worked unfortunately. In fact, worse than that, it's continuing to hunt for stability and now I'm currently syncing at 27Mbps down (SNR margin 14.7dB !) and still no more stable.

Please put it back to how it was when I connected at 73Mbps and I will live with the disconnects.

(Will try to follow this up with customer services via phone now too.)

Thanks,
Mark
markr77
Grafter
Posts: 30
Fixes: 2
Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

Hi Plusnet,

An engineer has now visited (same engineer as October) but no change seen. My connection is still disconnecting.

1. Please can you switch out my line card at the exchange ( Plusnet engineer only). Openreach cannot do this.

2. Please move me back to the maximum-speed stability profile (SNR margin 3dB). The profile makes no difference to this issue so move me to the fastest one.

Thanks,
Mark
jab1
Seasoned Hero
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Registered: ‎24-02-2012

Re: Is Noise Margin manual override possible?

@markr77 Only BTOR can change line cards, and anyway, Plusnet do not have any engineers.

John
markr77
Grafter
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Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

Just relaying what the BT Openreach Engineer said to me, which was that the line cards are in a locked room at the exchange which Openreach are not given access to, only Plusnet. He said go through Plusnet.
jab1
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Registered: ‎24-02-2012

Re: Is Noise Margin manual override possible?

In that case, the engineer needs fully retraining. The line-cards are not in a locked room - they are accessible in the mainframes, and only BTOR have access to the exchange.

He is correct in saying that the request for further investigation has to come from PN, but the decision to change line-cards or any other connections has to be made after an engineer has determined that it would have a beneficial effect.

John
markr77
Grafter
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Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

Can't comment on engineer competency.
RealAleMadrid
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Re: Is Noise Margin manual override possible?

Surely for FTTC the line cards are in the FTTC cabinet and all the broadband data goes from there to the head end exchange in a single fibre It would seem that the OR "engineer" doesn't  have a clue.

jab1
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Registered: ‎24-02-2012

Re: Is Noise Margin manual override possible?

Yup, you are correct, @RealAleMadrid - I was forgetting the different set-up for FTTC as I'm still on ADSL and was thinking that way.

As you say, the 'engineer' didn't have a clue, he was obviously relying on the fact that the general public don't either, and giving that guff to avoid having to do any more work.

From what I've read in this topic, it needs escalating to an experienced SFI, but you have to be rather persistent to get this done.

John
markr77
Grafter
Posts: 30
Fixes: 2
Registered: ‎16-02-2012

Re: Is Noise Margin manual override possible?

He visited the exchange and changed some connectors. He said I could try switching out the line card but that's in a room Openreach have no access to.

Which FTTC broadband providers would use a different line card at the exchange? So a switch would be done as part of a provider move I mean.
jab1
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Registered: ‎24-02-2012

Re: Is Noise Margin manual override possible?

I'm not going to get involved in this too deeply, as it appears there is some massive confusion, and as I said, I have no experience of FTTC other than what I pick up on here and elsewhere, but believe me ONLY BTOR staff have access to BT equipment in the exchange.

I assume, but don't know so not going to really comment, but LLU ISPs - TalkTalk, Sky for instance may have their own equipment - I know they do for ADSL lines - but whether the same applies in the FTTC environment, I'm not sure.

John
RealAleMadrid
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Re: Is Noise Margin manual override possible?

@markr77  As I said in my earlier reply #11 for FTTC the line cards are in the FTTC cabinet not at the exchange. There is nothing that the OR guy could have done at the exchange. All providers on the Openreach FTTC service use the same FTTC cabinets and the same line cards.

I think the chap was confused and thinking of LLU suppliers of ADSL services where different suppliers for example TalkTalk have their own exchange equipment locked away and not accessible to Openreach. This does not apply to FTTC. 

@jab1  I think you are coming to the same conclusion as I did, a lot of confusion caused by a very unhelpful or untrained OR operative who appears to think that Plusnet have their own equipment at the exchange..🙁