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Weird Noise Margin Changes.

oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Weird Noise Margin Changes.

I've mentioned this before but as it's still happening I thought I'd give it another go.
We live 900+ feet ASL on the top of a hill on the outskirts of Sheffield with "Nothing between us and the Urals" as Rigsby used to say.
Background RF noise is very high and if I had any fillings I'm sure that I would receive Radio Moscow on them.
A long drop wire doesn't help.
My noise margin figures toggle between two states which is puzzling me.
Normally my Billion 7300N indicates a NM of circa 6 dB to 6.3 dB during the day and then begins to drop as night falls.
By 7pm it is down to circa 3 dB and by 11 pm is still hanging on to sync at around 0 dB.
Most nights it loses sync in the early hours and reconnects at around 6 dB which it is still at the next morning.
However every now and again, it remains at around  6dB throughout the night and day and hangs on to sync for a week or so at that sort of NM.
It then loses sync during night-time and goes back to it's usual behavior.
I've got another router, a Netgear DGN2200 which behaves in a similar fashion except that it loses sync at about 3 dB, but when the line is going through it's purple patch it too holds sync for about a week.
My attenuation is around 44 dB on a EO line. My sync speed is always at 6655 kb/s give or take a few dB
Any ideas anyone.
26 REPLIES
Community Veteran
Posts: 6,313
Thanks: 86
Fixes: 3
Registered: 08-01-2008

Re: Weird Noise Margin Changes.

The consistent sync speed suggests that you are likely on a banded profile: http://www.plus.net/support/broadband/speed_guide/broadband_terminology.shtml#bandedProfiles
3328kb/s - 6656kb/s
Call me 'w23'
At any given moment in the universe many things happen. Coincidence is a matter of how close these events are in space, time and relationship.
Opinions expressed in forum posts are those of the poster, others may have different views.
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: 18-07-2007

Re: Weird Noise Margin Changes.

Hi there,
It is indeed banded and that is indeed the band Smiley
@oldgeezer, we can do an SNR reset and reset that for you which will let the line retrain, but it'd probably be worth putting interleaving back on until we're sure the line is stable - it was dropping up to the banding being applied as shown here:
<img src="http://ccgi.psmith12.plus.com/visradius/generated/image13582650736577.png"/>
We can then remove interleaving once we're sure the line has trained and all is good. Please let us know if you'd like to go ahead with that?
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

@matt
I'm not really sure what is happening, it all went a bit doolally when I asked to be put on the unlimited product.
I got an email saying that my request for interleaving to be turned off was proceeding. The thing was that I hadn't asked for it to be turned off.
My member centre indicates that it is on at the moment.
I think most of my problems stem from the very high noise interference, up here in the clouds. My set-up here is optimised with the router connected straight to a BT faceplate filter.
I don't notice any dropouts, the Billion reconnects automatically in seconds.
I have had sync speeds of 8000 Kb/s and download speeds of 7000+Kb/s in the past but my line seems more noisy at the moment.
If you could coax a bit more speed out of it, it would be nice, but if it resets to the banded profile I shall not be surprised. I'm just puzzled as to why the NM varies by about 6dB one week and then less than 0.5 dB the next.
Oldgeezer
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: 18-07-2007

Re: Weird Noise Margin Changes.

I believe the interleaving thing is a bug that we're looking into, but it won't change the status on your account. The question was more whether you'd be happy for an SNR reset to take place so the line can retrain? It's best done when the line will sync at its highest, so if you let us know when that is (and if you're happy to go ahead) then we'll arrange it for you.
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

@matt
It usually reaches a maximum at around 12 noon.
If you could give it a try I promise not to chuck my dummy out of the pram if it goes wrong.   Roll eyes
Got to be worth a try.
Thanks.
Oldgeezer
Plusnet Help Team
Plusnet Help Team
Posts: 13,401
Thanks: 243
Fixes: 68
Registered: 27-04-2007

Re: Weird Noise Margin Changes.

I've set myself a reminder to give that a try around noon for you.
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

Checked sync on my return home at 5pm.
Still banded at 6652 Kb/s at 6dB.
Reset router and still banded at 6656 now at 4.2 dB.
Might need dynamite to shift it.  Embarrassed
Regards.
Oldgeezer.
Plusnet Help Team
Plusnet Help Team
Posts: 13,401
Thanks: 243
Fixes: 68
Registered: 27-04-2007

Re: Weird Noise Margin Changes.

well, my outlook seems to have failed me, sorry about that.
No explosives needed, happy to try again tomorrow, I've used my phone to set the reminder!
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
Plusnet Help Team
Plusnet Help Team
Posts: 13,401
Thanks: 243
Fixes: 68
Registered: 27-04-2007

Re: Weird Noise Margin Changes.

SNR reset submitted! Smiley
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

Thank-you for the SNR reset.
I'm on about day 9 of my retraining period and after initially connecting at 8332 kb/s and re-connecting at various speeds about nine times it finally has stabilised at 7335kb/s  for about 3 days.
The BT IP profile is now showing at 6.47 Mb/s but my PN profile has remained stuck at 5.8 Mb/s.
Is it too soon to ask for someone at PlusNet Towers to administer a dose of Dulcolax to my PN profile ?
If so it should get me up to the 6Mb/s downloads I used to get before.
Regards.
Oldgeezer
Superuser
Superuser
Posts: 9,666
Thanks: 1,070
Fixes: 59
Registered: 06-04-2007

Re: Weird Noise Margin Changes.

The Digital Care Team staff are unlikely to be here again until Monday. I suggest giving the CSC a call and ask the agent to change your Plusnet profile to 6.4Mbps to match the BT IP Profile of 6.47Mbps.
Alternatively raise a ticket using Help Assistant path My Broadband Connection -> Other and make the same request.
David
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

I've done that, thank you.
I must say that the technical side of Plusnet have always been excellent as far as I'm concerned, both in response to this forum and through the helpdesk channel.
It's the billing side that don't seem to know where they are.
In the past I've had double billing and now I've had to complain that I've been charged an extra £2 for the Plusnet Connect despite being included free with my unlimited package.
In the event I tried it and didn't like it and un-installed it, but it should have been free for 3 months anyway even if I had still been on a basic package.
It would seem the billing systems can't keep up with changes to the packages.
I know that it will be refunded but things like this shouldn't be happening.
Oldgeezer
oldgeezer
Grafter
Posts: 212
Thanks: 1
Registered: 02-02-2010

Re: Weird Noise Margin Changes.

The Plusnet IP profile must have been waiting for the 10 day training period to finish.
It's now gone to 6.4 Mb/s giving me downloads of 6 Mb/s and I can download HD catch up TV without any problems.
I'm a happy bunny.  Smiley
Superuser
Superuser
Posts: 9,666
Thanks: 1,070
Fixes: 59
Registered: 06-04-2007

Re: Weird Noise Margin Changes.

Excellent. Get your money's worth from Unlimited now. Grin
David