Scaffolding and speed loss

Talktalk have just put me on LLU and the speed has been a bit erratic
but since yesterday the speed has dropped from 3 meg right down to
1.5. I don't know if this is down to them or the fact that my next
door neighbour had scaffolding erected yesterday for a roofing job and
my phone line runs against some of this. Is it possible the
scaffolding is acting as an aerial and sapping some of the signal. The
phone cable is the new multicore stuff fitted last year.
Trevor Smith

Trevor wrote:
> Talktalk have just put me on LLU and the speed has been a bit erratic
> but since yesterday the speed has dropped from 3 meg right down to
> 1.5. I don't know if this is down to them or the fact that my next
> door neighbour had scaffolding erected yesterday for a roofing job and
> my phone line runs against some of this. Is it possible the
> scaffolding is acting as an aerial and sapping some of the signal. The
> phone cable is the new multicore stuff fitted last year.
> Trevor Smith

It is certainly not impossible.

However you will probably be still 'learning' the line and erratic
connections at high speed dropping to more stable nes at lower speed are
part of the process.

On 24-Nov-2007, Trevor <(E-Mail Removed)> wrote:

> Is it possible the
> scaffolding is acting as an aerial and sapping some of the signal. The
> phone cable is the new multicore stuff fitted last year.

Unlikely, ADSL is a low frequency signal, the twisted pair attenuates
RF. Being twisted pair there should be little radiation of the signal to
leak away.
From other posts it appears that in some situations combinations
of attenuation and SNR can result in your profile being unstable.
If the error rate is below a threshold your rate is increased, a higher
error rate occurs and it's reduced, there is some hysteris built in
so it doesn't change every few minutes, and a sampling period
to eliminate short term anomalies.
A wireless link could be influenced by scaffolding.
If you were running at 3 meg then an old ADSL modem that
does't support ADSLmax and which forces the link to
run at the original ADSL standard might give a more stable
connection.
Also try chaining two cheapo T shaped Chinese filters.
First one into the BT faceplate, second one into it's
BT jack, phone into that, putting two filters in series with the
phone side. ADSL RJ11 MUST go into the one that is plugged
into the faceplate.
No change in phone quality or ringing, but it stabilised
my ADSL rate.
Sure it's not a TalkTalk problem, I'd go for a better ISP.

(E-Mail Removed) wrote:
> On 24-Nov-2007, Trevor <(E-Mail Removed)> wrote:
>
>> Is it possible the
>> scaffolding is acting as an aerial and sapping some of the signal. The
>> phone cable is the new multicore stuff fitted last year.
>
> Unlikely, ADSL is a low frequency signal,

I Mhz is not 'low frequency'. Its bang in the midle of the MW band..


> the twisted pair attenuates
> RF.

Yeah to some extent, but heck, you can run gigabit ethernet over twisted
pair, so its obviously *useless* at HF. ;-)


>Being twisted pair there should be little radiation of the signal to
> leak away.

Less, but not little.


> From other posts it appears that in some situations combinations
> of attenuation and SNR can result in your profile being unstable.
> If the error rate is below a threshold your rate is increased, a higher
> error rate occurs and it's reduced, there is some hysteris built in
> so it doesn't change every few minutes, and a sampling period
> to eliminate short term anomalies.

At least you got THAT bit right.

> A wireless link could be influenced by scaffolding.

ADSL IS wireless..just run down wires!! It runs - according to my router
which generates some pretty graphs - over a variety of frequencies
between 150kHz and 1.1MHz Thast te dowload spectrum
That's the upper part of the LW radio band and the lower half of the MW
band.

The upload runs between 25kHz and 125kHz

I guess that's why they call it 'broadband' haha.

It DOES pick up radio signals,especially at night or when the
ionospehere is right (cold dry air?) and you DO see that as a worsening
SNR and yes, bits of metal nearby will certainly AFFECT that, but by how
MUcH is very arguable.

On 24 Nov, 16:03, ato_...@hotmail.com wrote:
> On 24-Nov-2007, Trevor <tr...@hotmail.com> wrote:
>
> > Is it possible the
> > scaffolding is acting as an aerial and sapping some of the signal. The
> > phone cable is the new multicore stuff fitted last year.
>
> Unlikely, ADSL is a low frequency signal, the twisted pair attenuates
> RF. Being twisted pair there should be little radiation of the signal to
> leak away.
> From other posts it appears that in some situations combinations
> of attenuation and SNR can result in your profile being unstable.
> If the error rate is below a threshold your rate is increased, a higher
> error rate occurs and it's reduced, there is some hysteris built in
> so it doesn't change every few minutes, and a sampling period
> to eliminate short term anomalies.
> A wireless link could be influenced by scaffolding.
> If you were running at 3 meg then an old ADSL modem that
> does't support ADSLmax and which forces the link to
> run at the original ADSL standard might give a more stable
> connection.
> Also try chaining two cheapo T shaped Chinese filters.
> First one into the BT faceplate, second one into it's
> BT jack, phone into that, putting two filters in series with the
> phone side. ADSL RJ11 MUST go into the one that is plugged
> into the faceplate.
> No change in phone quality or ringing, but it stabilised
> my ADSL rate.
> Sure it's not a TalkTalk problem, I'd go for a better ISP.

Thanks for the suggestions. I have just checked the router stats and
DSLzone speed test and the results are
SNR Down=15 Up=16
Line Attenuation Down=41 Up=24
Data Rate Down=3923 Up= 390
On D-link DSL 320T
Speedtest result 1180kbps
So if it's doubtful it's the scaffolding the it looks like a call to
talktalk.
Trevor Smith

Trevor wrote:
> On 24 Nov, 16:03, ato_...@hotmail.com wrote:
>> On 24-Nov-2007, Trevor <tr...@hotmail.com> wrote:
>>
>>> Is it possible the
>>> scaffolding is acting as an aerial and sapping some of the signal. The
>>> phone cable is the new multicore stuff fitted last year.
>> Unlikely, ADSL is a low frequency signal, the twisted pair attenuates
>> RF. Being twisted pair there should be little radiation of the signal to
>> leak away.
>> From other posts it appears that in some situations combinations
>> of attenuation and SNR can result in your profile being unstable.
>> If the error rate is below a threshold your rate is increased, a higher
>> error rate occurs and it's reduced, there is some hysteris built in
>> so it doesn't change every few minutes, and a sampling period
>> to eliminate short term anomalies.
>> A wireless link could be influenced by scaffolding.
>> If you were running at 3 meg then an old ADSL modem that
>> does't support ADSLmax and which forces the link to
>> run at the original ADSL standard might give a more stable
>> connection.
>> Also try chaining two cheapo T shaped Chinese filters.
>> First one into the BT faceplate, second one into it's
>> BT jack, phone into that, putting two filters in series with the
>> phone side. ADSL RJ11 MUST go into the one that is plugged
>> into the faceplate.
>> No change in phone quality or ringing, but it stabilised
>> my ADSL rate.
>> Sure it's not a TalkTalk problem, I'd go for a better ISP.
>
> Thanks for the suggestions. I have just checked the router stats and
> DSLzone speed test and the results are
> SNR Down=15 Up=16

Very good.

> Line Attenuation Down=41 Up=24

Very good.

> Data Rate Down=3923 Up= 390

Not bad. Surprised its that low up..should be 448 dead.

Should be able to sync at 5-6M with that SNR..


> On D-link DSL 320T
> Speedtest result 1180kbps

So is all down to backhaul and ISP stuff. Cheap service? ;-)

> So if it's doubtful it's the scaffolding the it looks like a call to
> talktalk.

Doubt that will help. Either your BRAS is stuffed, or talktalk are
simply cheapskating bandwidth.

> Trevor Smith