Noise Margin Doubles every weekend????

All through the week noise margin will be around 10, syncing over 3meg, and then either friday or saturday, noise margin will double to 35 and stay like this for hours, now its syncing at 133, and bt have decreased line speed to 133, so now i have to wait 3 days for the increase again.


why would this happen?

So 'something' is being switched on, on either Friday or Saturday, which is screwing your signal, as a result, DLM is adjusting the speed etc, as a work around. plotting the times may help find the exact time this is happening. But my first guess would be to look around for something that is only switched on at these times. I presume your router is left on 24/7 ? If not, then maybe you are turning it on at different times on the weekends, and in this way catching the interferer at work. Ask if nieghbours are having problems at the same times. Another top tip, is to use a MW handheld radio, when just 'tuned out' , this can sometimes track these faults down, as when nearby the interference can be heard.

Happy hunting.

In reply to:

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So 'something' is being switched on

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You mean something is being switched OFF. If the noise margin doubles, then the noise is much less (or the ADSL signal is louder, which seems much less likely).

PS -just read the OP's post again. The margin is increasing corresponding to a drop in sync speed, so in fact that suggests that the noise might not be changing at all and it's something entirely different that's causing the sync speed to drop, the margin increase just being a side effect. Sounds like a fault to me.

Edited by cahaddras (Sun 04-Mar-07 15:48:21)

No, it sounds like interference to me.....the margin is going up so as max can cope....tied with the drop in sync speed..
You would have been correct if this were vanilla ADSL.

Thats right!

All week my router is stable at 3 megs, noise margin about 11.5 - 13.

My isp puts me at about 2.5megs when they update my profile.

Now the last two weekends last week on Friday and this week yesterday, the router will keep cutting out and then when it finnaly reconnects it syncs at 133 and noise is about 37. So bt then cut my line down to 133kb/s then I have to now wait another 3 days for it to increase back yp to 2megs. such a pain. But I honestly dont no what it could be, as all week, my router never cuts out, and its stable untill about 6-9pm on a friday or saturday.

Now (sunday pm) the router is back to 3meg sync and 13 noise.

So since 9pm last night untill i come home at 12pm today the noise was still 30 and sync was 133, i tried to eliminate phones, filters, cables, electric items..but nothing changed, but since i started messing around with things the noise started to decrease and its now back up to normal, but I HAVN'T CHANGED a thing.

So it's strange

Anymore opinions?

An increase in signal to noise ratio means that the signal has got stronger in comparison with the noise or the noise has decreased in comparison with the signal.

The SNR Margin is the difference between the measured SNR and the level of SNR which is necessary for the service to work. If it is negative, the noise is too high, if it is positive, it is enough, though a small positive margin is required (I think 6dB which means that the measured SNR is about four times as high as the minimum).

So what is the problem? I agree with Cahaddras. A decrease in noise is not causing this problem, so something else must be.

If you have definitely eliminated every possibility at your home then it sounds as if an external noise source is being switched on for a long enough period at the beginning of the weekend to totally kill your profile. Without finding out what that noise source is there is little you can do about it unless you can get your ISP to raise it with BT and hope they can find it for you.

However, if it was an external source affecting you that badly I would be very surprised if it wasn't also affecting some of your neighbours on MAX, at least to some extent. So if there are any close to you on MAX it might be worth a chat with them.

Yeah, Will see if anyone else has a problem..

It's strange, my router doesn't resync or loose connection all week, then fri/sat in the evening it will cut out and take forever to resync/reconnect, then it's buggered for hrs, then my profile soon follows.

I will keep an eye on it, How do I log when this happens if im not at home at the time?

You could try

http://www.l8nc.com/

or depending on your router you could try the DMT tool;

http://dmt.mhilfe.de/