Kitz Forum
Broadband Related => Broadband Technology => Topic started by: nicpy on February 09, 2009, 08:01:50 AM
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I have been monitoring my `stats` for some time now, normally the SNRM sits at around 15 to 17Db, but then, randomly it will drop to around 7Db and stay there for maybe 2 or 3 hours before returning to around 15 to 17Db again!, it does not happen daily, nor with any regular pattern, could be morning or afternoon or evening. It does not affect my sync speed (7616) or speed tests. I am using a Netgear DG834GT router. There isn`t anything in our house or locally that I can think of that might be causing this increase in `noise`, Have you any thoughts on this? :)
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There are many possibilities, and really the only way to home in on the cause is to follow a systematic approach. Our normal advice is here (http://www.kitz.co.uk/adsl/troubleshooting.htm) but one specific question arises - do you hear any crackling on the telephone when the connection is in its low noise margin state?
It often helps diagnosis to monitor the noise margin continuously. If your router is compatible, we can recommend that you install Routerstats (http://www.vwlowen.co.uk/internet/files.htm) and run it for a few days to see exactly what happens to the noise margin.
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Still puzzling me I`m afraid, I have been running routerstats for some time now and there is nothing happening that is corresponding with the drop in noise margin. The phone remains clear with no noise as the SNR drops. It does not affect download speeds. I get the same issue with different routers. It`s just one of those things that I would like to get the answer to. It has done it again this morning, the PC has been on all night with a recorded noise margin of between 15Db and 17Db. At 07.43 it dropped to 7.9Db rock steady, and that’s where it is now, and will if recent patterns repeat themselves, stay for the next three or four hours before returning to earlier levels? ............I don`t know about the SNR but It looks like I`m suffering from the attempting to learn about ADSL virus! :)
Later on !
At 10.36 it has jumped straight back up to 15.3Db???
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Hi can you show the graph ??
Jeff
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Have attached graph`s as events occured earlier today.
[attachment deleted by admin]
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That certainly is a weird one. I suppose the obvious question is: do you have any electrical equipment which operates at the times when the noise margin is low?
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Hi
I get similar plots on my snr margin not as pronounced , mine drops a max of about 3 db and can remain for a couple of hours or only 15 minutes . Reoccurs 2 or 3 times a day . see below with Kitz comments
http://forum.kitz.co.uk/index.php?topic=3989.0
When you say it drops RANDOMLY is that to say there is NO time correlation at all between these events ?
Apart from the drop your line appears to be VERY quiet . Have you followed the advice in the LINK given by Roseway ?
Regards Jeff
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I have turned everthing off at the mains switch..................except for the PC! and it still happens, last time it was late morning lasting through to late `ish` afternoon
(see textfile attachment)
It occurs at completely random times am, pm, sometimes not for days, but mostly for two to five hours at a time
I have also followed the advice given by Roseway :)
My very recent successful communication with my ISP in getting interleaving taken off the line has made no difference to this problem
[attachment deleted by admin]
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Something like a sewage pump or similar nearby?
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Unlikely, we live in residential area, the exchange is about 180 metres away. Nothing but houses between here and the exchange
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Sewage pumps are all over the place. Your drains just go into a big underground chamber, when the level rises the pumps kick in automatically to move it further along.
Not saying it is that specifically, but there are loads of utility things like that hidden away that you're not aware of.
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Yes, thank you for your thought`s, it seems probable that something is happening outside our house, maybe it`s one of those things that there is not an answer to, at least without digging up the streets! It doesn`t seem to have a direct affect on my connection, but it would be nice to `nail it`, so if anyone gets a `eureka` moment with the answer............I`d like to be the first to know!
Thanks again for your input :)
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This looks like it could be a REIN issue. Even if you don't have any electrical equipment that could be causing the problem, as has been suggested already it could be outwith your property, and could even be in a neighbouring house, e.g. a computer monitor generating the noise.
I'd suggest getting yourself a portable radio and following the instructions here (http://www.kitz.co.uk/adsl/rein.htm)during a period of lowered SNR margin. Start off in your own house and then work your way up the street towards the exchange to see if you can detect anything.