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Request for a noise margin fix

VileReynard
All Star
Posts: 11,186
Thanks: 305
Fixes: 11
Registered: ‎01-09-2007

Request for a noise margin fix

For reasons unknown, BT have upped my noise margin from a stable 6dB to 12dB.
So I raised a ticket with Plusnet - 26450832
In part, the response consisted of
Quote
Thank you for your request. The current SNR rate that you are receiving is within the required range of 6-15dB

I mentioned that I'd been able to override my modem to get the noise margin down to 9dB for which I was told:-
Quote
...the SNR rate does not require manual adjustment. The main reason for this being that the system monitors each individual line and if the line's SNR is 9dB it will automatically reconfirgure the line to that rate again.
I know this to be false - my line will never recover from a noise margin hit.
Is all of this a new policy?
No investigation of my line was undertaken by Plusnet.
BTW Was SA involved in this "analysis" - I don't have the impression that the standard of grammar is quite up to Plusnet's usual standards?

12 REPLIES
imroberts
Grafter
Posts: 52
Registered: ‎15-06-2007

Re: Request for a noise margin fix

It has become more difficult recently for us to convince BT Wholesale to make manual SNR changes. Usually we can convince them to do so if we put forward the right arguments, however I have known for them to refuse outright on occasion.
I can confirm that SA were not involved in this analysis, however I am sorry if you feel the response you had was not up to usual levels of support.
I have updated your fault ticket and have put a specific request to BT Wholesale requesting the SNR be changed to 9dB as per your request. I cannot guarantee this will be done on our first request though  Roll eyes
VileReynard
All Star
Posts: 11,186
Thanks: 305
Fixes: 11
Registered: ‎01-09-2007

Re: Request for a noise margin fix

Quote from: Ian
It has become more difficult recently for us to convince BT Wholesale to make manual SNR changes. Usually we can convince them to do so if we put forward the right arguments, however I have known for them to refuse outright on occasion.
I have updated your fault ticket and have put a specific request to BT Wholesale requesting the SNR be changed to 9dB as per your request. I cannot guarantee this will be done on our first request though  Roll eyes

I think someone has misread my request!!!
I mention that BT had increased my noise margin from 6dB to 12dB but that I had succeeded in getting my modem to reduce this to 9dB.
I don't want 9dB - I want my 6dB back!!!!!!!
See attachment for the last months performance (in green).

imroberts
Grafter
Posts: 52
Registered: ‎15-06-2007

Re: Request for a noise margin fix

Quote from: axisofevil
I think someone has misread my request!!!
I mention that BT had increased my noise margin from 6dB to 12dB but that I had succeeded in getting my modem to reduce this to 9dB.
I don't want 9dB - I want my 6dB back!!!!!!!

Apologies, that would be my fault!   Embarrassed   I shall change this to a 6dB request in the morning when I get to work.
Also please bear in mind that it is probably line instability or interference has caused the SNR to increase in the first place, as such bear in mind that if we are successful in getting this reduced for you there is no guarantee that it won't increase again at some point.
VileReynard
All Star
Posts: 11,186
Thanks: 305
Fixes: 11
Registered: ‎01-09-2007

Re: Request for a noise margin fix

Thanks for your help.
I can't think that it's your "average" interference - since it only kicks in every few months or so.
When ADSL2 arrives will it reset noise margin automatically (the present system is strictly one-way)?

imroberts
Grafter
Posts: 52
Registered: ‎15-06-2007

Re: Request for a noise margin fix

Quote from: axisofevil
When ADSL2 arrives will it reset noise margin automatically (the present system is strictly one-way)?

I honestly couldn't answer that question. I'll update you tomorrow if I can find out.
*Apparently* though, DSL Max is meant to reset the noise margin automatically if the line remains stable for 14 days. I'm yet to see it happen though  Cheesy
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Request for a noise margin fix

I'd heard 28 days, but equally, haven't seen that happen.
Community Veteran
Posts: 3,789
Registered: ‎08-06-2007

Re: Request for a noise margin fix

I'd heard "when you least expected".  And I've seen that happen perhaps once Smiley
B.
imroberts
Grafter
Posts: 52
Registered: ‎15-06-2007

Re: Request for a noise margin fix

Quote from: axisofevil
When ADSL2 arrives will it reset noise margin automatically (the present system is strictly one-way)?

Got an answer for you.
Apparently on ADSL2 the SNR can increase or decrease as often as every 3 days.
Whether we will see this happen in practice, I guess we'll find out Smiley
imroberts
Grafter
Posts: 52
Registered: ‎15-06-2007

Re: Request for a noise margin fix

Quote from: Barry
I'd heard "when you least expected".  And I've seen that happen perhaps once Smiley

Once more than me  Grin
Though I guess from a support perspective I only generally see these issues when they don't happen, so I might be a little biased.
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Request for a noise margin fix

Wonder who your source of information was Ian? Smiley
Basically, the line will be try picking up a better SNR level after 3 days.  If it becomes instable again, then the SNR will raise for a longer period, then go back down again if the line is stable, and so on and so on.
VileReynard
All Star
Posts: 11,186
Thanks: 305
Fixes: 11
Registered: ‎01-09-2007

Re: Request for a noise margin fix

That sounds reasonable.
I've never seen it happen though.  Smiley

James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Request for a noise margin fix

Jeremy,
That's just the BT implementation of ADSL2+.
It's different for LLU suppliers.