Max speed with these figures?

Here are the line quality figures reported by my Netgear DG834G router...

ADSL Link---------------Downstream Upstream
Connection Speed----- 576 kbps 288 kbps
Line Attenuation------- 39 db 11 db
Noise Margin------------ 13 db 31 db

Can anyone tell me what the max speeds are that I can hope to get on my
line? I'm 1.4Km from the exchange as the crow flies. Is there a website
where I can punch in these numbers and get an answer?

Errr, strangely, while writing this, my downstream noise margin has
increased to 20 db from thre 13 db reported above. The other figures have
all remained steady. Yesterday I was seeing about 16-17 db for this figure.
I don't know what the significance of this is, or whether bigger or smaller
numbers are better. Any thoughts?

Thanks,
Tim.

"Tiny Tim" <_(E-Mail Removed)> wrote in message
news:421ee21c$0$8210$(E-Mail Removed)...
> Here are the line quality figures reported by my Netgear DG834G router...
>
> ADSL Link---------------Downstream Upstream
> Connection Speed----- 576 kbps 288 kbps
> Line Attenuation------- 39 db 11 db
> Noise Margin------------ 13 db 31 db

I think that's gonna be 2Mbs for your line.

>
> Can anyone tell me what the max speeds are that I can hope to get on my
> line? I'm 1.4Km from the exchange as the crow flies. Is there a website
> where I can punch in these numbers and get an answer?
>
> Errr, strangely, while writing this, my downstream noise margin has
> increased to 20 db from thre 13 db reported above. The other figures have
> all remained steady. Yesterday I was seeing about 16-17 db for this
figure.
> I don't know what the significance of this is, or whether bigger or
smaller
> numbers are better. Any thoughts?
>
> Thanks,
> Tim.
>
>

On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
wrote:

>Here are the line quality figures reported by my Netgear DG834G router...
>
>ADSL Link---------------Downstream Upstream
>Connection Speed----- 576 kbps 288 kbps
>Line Attenuation------- 39 db 11 db
>Noise Margin------------ 13 db 31 db
>
>Can anyone tell me what the max speeds are that I can hope to get on my
>line? I'm 1.4Km from the exchange as the crow flies. Is there a website
>where I can punch in these numbers and get an answer?
>
>Errr, strangely, while writing this, my downstream noise margin has
>increased to 20 db from thre 13 db reported above. The other figures have
>all remained steady. Yesterday I was seeing about 16-17 db for this figure.
>I don't know what the significance of this is, or whether bigger or smaller
>numbers are better. Any thoughts?

Two observations here.

Firstly, 13db is a very poor SNR for a line with relatively low
attenuation. It should be much higher than that. I would suggest
that you need to get your hands on some decent quality filters - and
try plugging your router into the master socket to see if there is
some sort of interference from your internal wiring. A decent filter
might make all the difference.

Secondly, if your SNR is jumping around by as much as 7db it further
suggests a fair amount of (variable) interference on the line. Again,
decent filters may help reduce the effect of this - but you can never
be entirely sure of the quality of the line.

Even though I have an attenuation of over 50db on my line, the SNR was
always very high on 512kbit (around 35db and stable). Unfortunately
after a recent migration this dropped to 25db (probably a different
card at the exchange) but even still BT regraded me to 2mb and I have
a stable connection. It may be a long line, but it seems to be quite
high quality - which one would hope given that the oldest houses on
the estate are less than 3 years old so the lines will all be quite
new.

On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
wrote:

>Here are the line quality figures reported by my Netgear DG834G router...
>
>ADSL Link---------------Downstream Upstream
>Connection Speed----- 576 kbps 288 kbps
>Line Attenuation------- 39 db 11 db
>Noise Margin------------ 13 db 31 db
>
>Can anyone tell me what the max speeds are that I can hope to get on my
>line? I'm 1.4Km from the exchange as the crow flies. Is there a website
>where I can punch in these numbers and get an answer?
>
>Errr, strangely, while writing this, my downstream noise margin has
>increased to 20 db from thre 13 db reported above. The other figures have
>all remained steady. Yesterday I was seeing about 16-17 db for this figure.
>I don't know what the significance of this is, or whether bigger or smaller
>numbers are better. Any thoughts?
>

Bigger numbers are better for SNR.

The 13 would have made it very iffy for more than 1Mb, although the
attenuation would be OK for 2Mb.

If SNR (downstream) is normally up around 20, I would expect you to be
able to get 2Mb.
--
Alex Heney, Global Villager
Who is "they" anyway?

To reply by email, my address is alexATheneyDOTplusDOTcom

"Alex Heney" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
> wrote:
>
>>Here are the line quality figures reported by my Netgear DG834G router...
>>
>>ADSL Link---------------Downstream Upstream
>>Connection Speed----- 576 kbps 288 kbps
>>Line Attenuation------- 39 db 11 db
>>Noise Margin------------ 13 db 31 db
>>
>>Can anyone tell me what the max speeds are that I can hope to get on my
>>line? I'm 1.4Km from the exchange as the crow flies. Is there a website
>>where I can punch in these numbers and get an answer?
>>
>>Errr, strangely, while writing this, my downstream noise margin has
>>increased to 20 db from thre 13 db reported above. The other figures have
>>all remained steady. Yesterday I was seeing about 16-17 db for this
>>figure.
>>I don't know what the significance of this is, or whether bigger or
>>smaller
>>numbers are better. Any thoughts?
>>
>
> Bigger numbers are better for SNR.
>
> The 13 would have made it very iffy for more than 1Mb, although the
> attenuation would be OK for 2Mb.
>
> If SNR (downstream) is normally up around 20, I would expect you to be
> able to get 2Mb.

Thanks for the replies, guys. I think I have some other filters lurking
about so will try swapping them. I do have the router plugged into a 15m
extension cable and there are two DECT phones plugged into the master socket
via dialler box, together with the extension, so I'll have a fiddle there
too.

"Tiny Tim" <_(E-Mail Removed)> wrote in message
news:421ef713$0$35859$(E-Mail Removed)...
> "Alex Heney" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
>> wrote:
>>
>>>Here are the line quality figures reported by my Netgear DG834G router...
>>>
>>>ADSL Link---------------Downstream Upstream
>>>Connection Speed----- 576 kbps 288 kbps
>>>Line Attenuation------- 39 db 11 db
>>>Noise Margin------------ 13 db 31 db
>>>
>>>Can anyone tell me what the max speeds are that I can hope to get on my
>>>line? I'm 1.4Km from the exchange as the crow flies. Is there a website
>>>where I can punch in these numbers and get an answer?
>>>
>>>Errr, strangely, while writing this, my downstream noise margin has
>>>increased to 20 db from thre 13 db reported above. The other figures have
>>>all remained steady. Yesterday I was seeing about 16-17 db for this
>>>figure.
>>>I don't know what the significance of this is, or whether bigger or
>>>smaller
>>>numbers are better. Any thoughts?
>>>
>>
>> Bigger numbers are better for SNR.
>>
>> The 13 would have made it very iffy for more than 1Mb, although the
>> attenuation would be OK for 2Mb.
>>
>> If SNR (downstream) is normally up around 20, I would expect you to be
>> able to get 2Mb.
>
> Thanks for the replies, guys. I think I have some other filters lurking
> about so will try swapping them. I do have the router plugged into a 15m
> extension cable and there are two DECT phones plugged into the master
> socket via dialler box, together with the extension, so I'll have a fiddle
> there too.

I just resited the router directly into the master socket and removed the
phones but kept the existing filter. New figures are....

ADSL Link---------------Downstream Upstream
Connection Speed----- 576 kbps 288 kbps
Line Attenuation------- 37 db 11 db
Noise Margin------------ 31 db 31 db

so I guess that's quite a big improvement on the downstream. The problem
I've now got is what to do about it, because the master socket is in the
hall and I need a wired ethernet connection to my Media Center PC and Xbox
in the living room. I already use the wireless LAN for three laptops so
don't want to use up any more RF bandwidth (or spend extra money) to make
the Xbox and MCE PC wireless too.

In article <(E-Mail Removed)>,
Alex Heney <(E-Mail Removed)> wrote:
>On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
>wrote:
>
>>Here are the line quality figures reported by my Netgear DG834G router...
>>
>>ADSL Link---------------Downstream Upstream
>>Connection Speed----- 576 kbps 288 kbps
>>Line Attenuation------- 39 db 11 db
>>Noise Margin------------ 13 db 31 db
>>
>
>Bigger numbers are better for SNR.
>
>If SNR (downstream) is normally up around 20, I would expect you to be
>able to get 2Mb.

Alex, not doubting what you say just trying to understand how SNR relates to
Noise Margin.
Obviously it is good to have a high SNR (more signal, less noise)
but I notice that Tims figure of 13db is for "Noise Margin"
Is the the same as SNR? I would have thought that if this was SNR the figure
would be 13 and not 13db i.e. a ratio and not a value?

Pete

In article <cvn8o5$bdu$1$(E-Mail Removed)>,
(E-Mail Removed)er says...
> In article <(E-Mail Removed)>,
> Alex Heney <(E-Mail Removed)> wrote:
> >On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
> >wrote:
> >
> >>Here are the line quality figures reported by my Netgear DG834G router...
> >>
> >>ADSL Link---------------Downstream Upstream
> >>Connection Speed----- 576 kbps 288 kbps
> >>Line Attenuation------- 39 db 11 db
> >>Noise Margin------------ 13 db 31 db
> >>
> >
> >Bigger numbers are better for SNR.
> >
> >If SNR (downstream) is normally up around 20, I would expect you to be
> >able to get 2Mb.
>
> Alex, not doubting what you say just trying to understand how SNR relates to
> Noise Margin.
> Obviously it is good to have a high SNR (more signal, less noise)
> but I notice that Tims figure of 13db is for "Noise Margin"
> Is the the same as SNR? I would have thought that if this was SNR the figure
> would be 13 and not 13db i.e. a ratio and not a value?
>
> Pete
>
SNR is the noise margin. 13dB is a ratio. The signal is 20 times greater
than the noise.
--
Mugwump

Reply to 'usenetmail{at}discworld{dot}org{dot}uk

"Mugwump" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed). ..
> In article <cvn8o5$bdu$1$(E-Mail Removed)>,
> (E-Mail Removed)er says...
>> In article <(E-Mail Removed)>,
>> Alex Heney <(E-Mail Removed)> wrote:
>> >On Fri, 25 Feb 2005 08:30:14 -0000, "Tiny Tim" <_(E-Mail Removed)>
>> >wrote:
>> >
>> >>Here are the line quality figures reported by my Netgear DG834G
>> >>router...
>> >>
>> >>ADSL Link---------------Downstream Upstream
>> >>Connection Speed----- 576 kbps 288 kbps
>> >>Line Attenuation------- 39 db 11 db
>> >>Noise Margin------------ 13 db 31 db
>> >>
>> >
>> >Bigger numbers are better for SNR.
>> >
>> >If SNR (downstream) is normally up around 20, I would expect you to be
>> >able to get 2Mb.
>>
>> Alex, not doubting what you say just trying to understand how SNR relates
>> to
>> Noise Margin.
>> Obviously it is good to have a high SNR (more signal, less noise)
>> but I notice that Tims figure of 13db is for "Noise Margin"
>> Is the the same as SNR? I would have thought that if this was SNR the
>> figure
>> would be 13 and not 13db i.e. a ratio and not a value?
>>
>> Pete
>>
> SNR is the noise margin. 13dB is a ratio. The signal is 20 times greater
> than the noise.

Hi chaps :-) I discovered in moving things about that although I had a
filter for the router, at the end of the extension cable, I did not have a
filter on the phones by the master socket. I don't know quite what happened
when I reconnected things as they were but Noise Margin plummeted to just 4
db on the downstream and there was audible noise on the phone line. I have
added a filter at the master socket for the phones and now I not only have
peace and quiet but I also have a Noise Margin of 31 db and Line Attenuation
of 38db on the downstream. Hopefully that is more than enought to give me a
stable 2Mb connection and possibly more when the 8Mb speeds become
available.

Cheers,
Tim.

On Fri, 25 Feb 2005 13:21:09 +0000 (UTC), Pete
<(E-Mail Removed)> wrote:

>Obviously it is good to have a high SNR (more signal, less noise)
>but I notice that Tims figure of 13db is for "Noise Margin"
>Is the the same as SNR?

noise margin is the difference between the SNR and the required SNR
for the service speed.

> I would have thought that if this was SNR the figure
>would be 13 and not 13db i.e. a ratio and not a value?

dB is the log of a ratio 10 log(ratio) and the like.

Phil