Why does my Attenuation and S/N Ratio change daily?

CurlyWhirly · 2 Apr 2006 at 15:14

With Max DSL recently being in the headlines I never took any notice of my line statistics before.
However since monitoring it occasionally, I notice that both my Attenuation and S/N ratios change on a daily basis, sometimes for the worse and sometimes for the better.

How is this as surely the telephone line between my house and the exchange is static unless work is being carried out on it that could affect the line stats :confused:

Scottland · 2 Apr 2006 at 15:38

How much do they change by?

CurlyWhirly · 2 Apr 2006 at 16:26

Scottland said:
How much do they change by?

My Attenuation is usually at 56dB but can go 3dB either way i.e. 53dB - 59dB.

With my SNR, it is usually at 25.5dB but can vary by 2dB either way i.e. between 23.5dB and 27.5dB.

Is this normal :confused:

acantril · 2 Apr 2006 at 16:49

CurlyWhirly said:
My Attenuation is usually at 56dB but can go 3dB either way i.e. 53dB - 59dB.

With my SNR, it is usually at 25.5dB but can vary by 2dB either way i.e. between 23.5dB and 27.5dB.

Is this normal

Heat...any storms in the area... its afterall, just a piece of copper.

Paa` · 2 Apr 2006 at 17:03

You think thats bad?

My SNR is usually 31 on a 2mb line (good)

It will randomly drop to 6 where i get disconnected.

Two BT engineers have come round and found nothing, ive replaced internal cabling with high quality cable and tried 3 adsl modems/routers

I still get this annoying problem

Which im sure will cause even more problems when maxdsl is enabled on my line.

My DS attenuation is almost always 20-23 on a 2mb line tho. Does'nt change when the SNR goes mental.

Pretty annoying problem.

Anyone have clues? (sorry for thread hijack)

CurlyWhirly · 2 Apr 2006 at 17:13

Paa` said:
Which im sure will cause even more problems when max dsl is enabled on my line.

That's what I was thinking and why I asked if it was normal or not

It seems it is pretty normal then.

Scottland · 2 Apr 2006 at 17:26

Mine fluctates about 1-2dB every now and then, on both Attn and SNR.

I don't really worry about it, as already said it's only a pair of copper wires

AFAIK, with MAX if the line stats drop a little, then it would/should just sync up a lower speed. IIRC you have a threshold of about 30% below your max attainable sync speed, which if you start dropping below, you can report a fault on it.

CurlyWhirly · 2 Apr 2006 at 17:51

Thanks for the feedback Scottland
That's put my mind at rest

Teal · 2 Apr 2006 at 23:06

Scottland said:
IIRC you have a threshold of about 30% below your max attainable sync speed, which if you start dropping below, you can report a fault on it.

In the past BT have simply refused to provide an ADSL service if the line quality drops too far, it is not regarded as a 'fault' unless it affects voice quality.

Don't worry too much though some variation from day to day is normal and most common when it rains / dries out again as this will affect external connection and anywhere along the route with a leak

Scottland · 2 Apr 2006 at 23:14

Teal said:
In the past BT have simply refused to provide an ADSL service if the line quality drops too far, it is not regarded as a 'fault' unless it affects voice quality.

Don't worry too much though some variation from day to day is normal and most common when it rains / dries out again as this will affect external connection and anywhere along the route with a leak

Yeah, I was referring to IPStream MAX/Datastream MAX products, rather than the traditional ADSL/RADSL products. Although, I'll admit, the details I have on the "repair pricess" for MAX products is sketchy at the momeny, I should know more in the week