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  #1 (permalink)  
Old 06-03-2007, 07:30 PM
Dee
 
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Default adsl Noise Margin

Does a low Noise Margin level mean you're more likely to get
disconnected from your ADSL ISP?

Mine was 8db downstreeam and 20 db up stream

so tried plugging into the master socket directly and went to 21db down
and 26 db up

Then added additionals phones in the house and it's now reading 18db up
and 26db down

Line Attenuation remained constant throughtout with 51db up and 15.5db down

Connection Speed is 2272 kbps upload and 288 kbps up

this is after recent switch from Pipex to Plus Net

are these numbers good or bad?

Any of them a good indicator of line connection / sync problems? .. just
trying to find out why I seem to have been losing connection every
several hours (before moving the Netgear wifi router to the master socket)
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  #2 (permalink)  
Old 06-03-2007, 07:30 PM
Phil
 
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Default Re: adsl Noise Margin

Dee <archer1NO@SPAMjustemailPLEASE.net> wrote in
news:4296e525$0$573$ed2619ec@ptn-nntp-reader03.plus.net:

> Does a low Noise Margin level mean you're more likely to get
> disconnected from your ADSL ISP?


The higher the SNR margin the better. Each double of the ADSL speed will
reduce SNR by 6 - 8dB. A SNR of below 6dB and the connection is likely to
be a bit unstable.

--
Phil
http://www.philipchung.co.uk/
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  #3 (permalink)  
Old 06-03-2007, 07:30 PM
Phil Thompson
 
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Default Re: adsl Noise Margin

On Fri, 27 May 2005 10:15:28 +0100, Dee
<archer1NO@SPAMjustemailPLEASE.net> wrote:

>Does a low Noise Margin level mean you're more likely to get
>disconnected from your ADSL ISP?


yes. Below 0 it stops working, anything below 6 is likely to drop out
from time to time if it is variable.

>Mine was 8db downstreeam and 20 db up stream


not fantastic downstream, good upstream.

>so tried plugging into the master socket directly and went to 21db down
>and 26 db up


excellent. If you were to use a filtered faceplate and feed the router
from its unfiltered output you would get that most of the time.

http://www.adslnation.com/support/filters.php
http://www.clarity.it/acatalog/ADSL_Installation.html

>Then added additionals phones in the house and it's now reading 18db up
>and 26db down


presumably all the phones/faxes/Sky boxes/alarms/diallers/CLID units
are filtered, some filters are better than others.
http://www.adslnation.com/support/filters.php

This one has a money back guarantee
http://www.adslnation.com/products/xf-1e.php

but the 3 dB loss isn't massive.

>Line Attenuation remained constant throughtout with 51db up and 15.5db down


figures, its the amount of noise you're changing rather than the loss.

Phil
--
Tiscali - dialup speeds at Broadband prices, see
http://bbs.adslguide.org.uk/postlist...&Board=tiscali

AOL - the unlimited ISP of choice for heavy downloaders.
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  #4 (permalink)  
Old 06-03-2007, 07:31 PM
Dee
 
Posts: n/a
Default Re: adsl Noise Margin

Any thoughts why there would be such a difference between getting 21db
at the master socket and only 8db in my bedroom? (both without
additionals phones plugged in?)

Is that saying the telephone wiring in my house is not good or the
cables are too long from the master socket?

We have like 3 phones but 6 or 7 telephone sockets in the house - does
the more sockets you have reduce line quality within the house?

Does using mains powered telephones make any difference compared to line
powered?

Ideally I want my ADSL router inmy bedroom as I have 2 PC's in there and
the router has ethernet connections to 3 PC's but right now it's on WiFi
downstairs and I'm using a USB dongle to connect wirelessly but this
leaves me two Pc's that have no internet upstairs for lack of wifi card
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  #5 (permalink)  
Old 06-03-2007, 07:31 PM
Phil Thompson
 
Posts: n/a
Default Re: adsl Noise Margin

On Fri, 27 May 2005 12:49:21 +0100, Dee
<archer1NO@SPAMjustemailPLEASE.net> wrote:

>Any thoughts why there would be such a difference between getting 21db
>at the master socket and only 8db in my bedroom? (both without
>additionals phones plugged in?)


probably the wiring is passing sources of interference and feeding it
into the ADSL modem. Lights with transformers, flourescents, dodgy
immersion heaters, central heating. mains PSUs for LV appliances etc
etc can all add to the noise.

snipping the third (bell ring) wire can help. Use of twisted pair
cables rather than flat extension cables also.

You could still have a faceplate filter and run an unfiltered twisted
pair (Cat 5 ethernet cable) extension to where you need the router.

Phil
--
Tiscali - dialup speeds at Broadband prices, see
http://bbs.adslguide.org.uk/postlist...&Board=tiscali

AOL - the unlimited ISP of choice for heavy downloaders.
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  #6 (permalink)  
Old 06-03-2007, 07:31 PM
thoss
 
Posts: n/a
Default Re: adsl Noise Margin


In article <Xns96636C1C6B094pelhamnet@127.0.0.1>, Phil
<pylchung@hotmail.com> writes
>Dee <archer1NO@SPAMjustemailPLEASE.net> wrote in
>news:4296e525$0$573$ed2619ec@ptn-nntp-reader03.plus.net:
>
>> Does a low Noise Margin level mean you're more likely to get
>> disconnected from your ADSL ISP?

>
>The higher the SNR margin the better. Each double of the ADSL speed will
>reduce SNR by 6 - 8dB. A SNR of below 6dB and the connection is likely to
>be a bit unstable.
>

I am getting 38 db downstream and 29 db upstream on 512 kb/s. Does this
mean that I might have problems when I am upgraded to 2 Mb? Or 8 Mb?
--
Thoss
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  #7 (permalink)  
Old 06-03-2007, 07:31 PM
Phil
 
Posts: n/a
Default Re: adsl Noise Margin

thoss <thoss@thoss.plus.com> wrote in
news:vHPnMHBeFzlCFwP6@thoss.plus.com:

> I am getting 38 db downstream and 29 db upstream on 512 kb/s. Does
> this mean that I might have problems when I am upgraded to 2 Mb? Or 8
> Mb?


That should be no problem at all for 2Mbps and should be okay for 8Mbps.

--
Phil
http://www.philipchung.co.uk/
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  #8 (permalink)  
Old 06-03-2007, 07:31 PM
thoss
 
Posts: n/a
Default Re: adsl Noise Margin

In article <Xns9663A23DA1DD1pelhamnet@127.0.0.1>, Phil
<pylchung@hotmail.com> writes
>thoss <thoss@thoss.plus.com> wrote in
>news:vHPnMHBeFzlCFwP6@thoss.plus.com:
>
>> I am getting 38 db downstream and 29 db upstream on 512 kb/s. Does
>> this mean that I might have problems when I am upgraded to 2 Mb? Or 8
>> Mb?

>
>That should be no problem at all for 2Mbps and should be okay for 8Mbps.
>

Thanks for that reassurance.
--
Thoss
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  #9 (permalink)  
Old 06-03-2007, 07:35 PM
Steve
 
Posts: n/a
Default Re: adsl Noise Margin

>
> Line Attenuation remained constant throughtout with 51db up and 15.5db down
>
> Connection Speed is 2272 kbps upload and 288 kbps up



How did u get 2mb line with 51db Attenuation?

Steve


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  #10 (permalink)  
Old 06-03-2007, 07:36 PM
kraftee
 
Posts: n/a
Default Re: adsl Noise Margin


"Steve" <stek1961@mac.com> wrote in message
news:2005053110432450878%stek1961@maccom...
>>
>> Line Attenuation remained constant throughtout with 51db up and 15.5db
>> down
>>
>> Connection Speed is 2272 kbps upload and 288 kbps up

>
>
> How did u get 2mb line with 51db Attenuation?
>


A, the router isn't calibrated so the readings aren't necessarily correct..

B, they (like many others) are being upgraded without the ISP's bothering to
check to see whether the line is within spec or not..


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