cancel
Showing results for 
Search instead for 
Did you mean: 

Changing Noise Margin

itlity
Grafter
Posts: 71
Registered: ‎31-07-2007

Changing Noise Margin

I have now been hit by a new change of noise margin but this time not in the 'good' direction.
Almost 2 years ago because of repeated difficulties to connect to Internet in the morning I asked to change the line noise margin from 6 to 9dB. Life has been fine since then.
A few months ago, I noticed this noise ratio went down to 6dB -without me asking for anything. I was informed that it was because my line was fine and this was 'normal' automatic modification. However the BRAS profile didn't change, so where was the benefit for me: I was stuck to an actual IP profile @ 6Mbps even though my data rate was flirting with 8Mbps.
I wasn't happy because this was just a risk to come back to the situation which make me move from 6dB to 9dB in Sept 07.
A few weeks ago, I started to have these temporary hiccups during early morning connections. I was advised to cause disconnections in order to come back to 9dB. The disconnections I made didn't lead to any change. Over the following days, the same 'hiccups' continued but as this was only early in the morning, I accepted the situation.
This morning I noticed that I had problems to access the www.google.com web page. I went to check my router web page and noticed the noise ratio was at 12dB. My IP profile is now 50000kbps: worst ever!
My point is that automating is good but in this case, it only creates frustration: why this system wants to reduce the noise margin without giving me the benefit of it but only likely disadvantages of pushing the comms close to the limits just waiting to go over those limits. Basically, overall, this leads to get the absolute opposite of what the system is supposed to do: improvement.
This is nonsense to say the least: it creates frustration for the Customers, additional work for you as an ISP and BT.
What can I do to get my 9dB and 6.5Mbps IP profile?
Regards,
Patrice
5 REPLIES
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Changing Noise Margin

Hi Patrice,
I've run a check on your telephone line, which is showing errors on the downstream signal, which will have been the reason why the SNR was increased as presumably, these errors will have been more substancial on the previous setting.
I'd initially recommend swapping over your filters, ensuring that your router is wired directly to the master socket (test socket is better) via a filter and monitor the situation for a few days.
itlity
Grafter
Posts: 71
Registered: ‎31-07-2007

Re: Changing Noise Margin

OK. Thanks James.
Is there any chance that this is going to go back automatically down to 9dB after a while -if the line is fine?
If yes, is there any 'standard' time frame for that to happen: 3 days, a week?
Regards,
Patrice
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Changing Noise Margin

Hi Patrice,
It depends.  It can do, but generally takes a bit of time to do so - officially 28 days, but may be sooner.
itlity
Grafter
Posts: 71
Registered: ‎31-07-2007

Re: Changing Noise Margin

OK.
I disappeared during a while: complete loss of connection with my Belkin ADSL2 modem-router, I fall back to my old ADSL Zoom X3 modem-router. Throughput was very low but there was a connection. Switched off my Belkin for 5mn and put it back online: connection is up and running now.
Is there any way to ask for blocking the noise ratio to a certain level? I mean to prevent BT system to go beyond a noise margin of a certain level? Might be a dreamer on that one.
Anyway, thanks for the prompt replies.
Regards,
Patrice
James
Grafter
Posts: 21,036
Registered: ‎04-04-2007

Re: Changing Noise Margin

That's not something that we/BT would be able to do, but you may be able to do something using a piece of software called DMT.