Fairly regular noise breaks ADSL

Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
distance from the exchange these are reasonable figures.

Every day, at a random time between 05:30 and 07:00 the line drops, and
immediately re-synchronises. Quite often this is at 30dB SNR margin and
about 1Mbits/sec. If the router is rebooted a few hours later the speed and
SNR margin are back to normal.

There are occasional line drops at other times, and failures between 20:00
and 23:00 do occur more than about once per week.

This would not be a problem but for the fact that the BRAS profile stays at
around 1Mbits/sec, because it never has the required continuous connection
for more than 72 hours.

How do we find out the cause of the line drop?

We've tried:

1) router only connected to master socket, no phones whatever;

2) all electrical devices in the house (including hot water and central
heating) switched off (except the router itself, obviously.

There is no noticeable noise on the voice line.

Ideas, please?

TIA

--
Graham J

"Graham J" <graham@invalid> wrote in message
news:4da8667e$0$2517$(E-Mail Removed)...
> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
> distance from the exchange these are reasonable figures.
>
> Every day, at a random time between 05:30 and 07:00 the line drops, and
> immediately re-synchronises. Quite often this is at 30dB SNR margin and
> about 1Mbits/sec. If the router is rebooted a few hours later the speed
> and SNR margin are back to normal.
>
> There are occasional line drops at other times, and failures between 20:00
> and 23:00 do occur more than about once per week.
>
> This would not be a problem but for the fact that the BRAS profile stays
> at around 1Mbits/sec, because it never has the required continuous
> connection for more than 72 hours.
>
> How do we find out the cause of the line drop?
>
> We've tried:
>
> 1) router only connected to master socket, no phones whatever;
>
> 2) all electrical devices in the house (including hot water and central
> heating) switched off (except the router itself, obviously.
>
> There is no noticeable noise on the voice line.
>
> Ideas, please?
>
> TIA
>
> --
> Graham J
>
>

Not easy, but "switched off" is not really satisfactory nowadays.
"Unplugged" is what you need if you really want to eliminate you own house's
contents. (Difficult with many central heating systems, I know)

What are the attenuation figures?

PA

Graham J wrote:
> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
> distance from the exchange these are reasonable figures.
>
> Every day, at a random time between 05:30 and 07:00 the line drops, and
> immediately re-synchronises. Quite often this is at 30dB SNR margin and
> about 1Mbits/sec. If the router is rebooted a few hours later the speed and
> SNR margin are back to normal.
>
> There are occasional line drops at other times, and failures between 20:00
> and 23:00 do occur more than about once per week.
>
> This would not be a problem but for the fact that the BRAS profile stays at
> around 1Mbits/sec, because it never has the required continuous connection
> for more than 72 hours.
>
> How do we find out the cause of the line drop?
>
> We've tried:
>
> 1) router only connected to master socket, no phones whatever;
>
> 2) all electrical devices in the house (including hot water and central
> heating) switched off (except the router itself, obviously.

I tried also

reporting a line fault. Got another db more signals and a bit less hiss
after a half day rerouting my customers side lines

- reporting a broadband fault, got 5dB more signal after another half
day rerouting the E side.

- hunting all over my house wih an AM radio to find an source that
coincided with the noise bursts.



None of the above resulted ion any solution.

The problem mysteriously went away about 4 days after the last BT man
had finished giving me the shiniest line possible

I suspect, there was an exchange fault,, and someone swapped a card out.

Neither my ISP nor BT has ever reported back to me as to what might have
been done, or what the problem was.


>
> There is no noticeable noise on the voice line.
>
> Ideas, please?
>

My gut feeling is you should report a broadband fault to your ISP. If
your ISP is reluctant to take this up without you underwriting a
potential cost if it turns out that rats have eaten your microfilter,
then underwrite that cost.

Your line stats will reveal there IS a problem.

If they fail to find anything on the line, which is almost down to the
whim of the BT engineer who calls - so tea and biscuits are mandatory to
get him on your side, yelling and screaming at him are NOT - at least
they know there is an issue, and may monitor the exchange side for
issues that the line men can't see.



> TIA
>

Peter Able wrote:
> "Graham J" <graham@invalid> wrote in message
> news:4da8667e$0$2517$(E-Mail Removed)...
>> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
>> distance from the exchange these are reasonable figures.
>>
>> Every day, at a random time between 05:30 and 07:00 the line drops, and
>> immediately re-synchronises. Quite often this is at 30dB SNR margin and
>> about 1Mbits/sec. If the router is rebooted a few hours later the speed
>> and SNR margin are back to normal.
>>
>> There are occasional line drops at other times, and failures between 20:00
>> and 23:00 do occur more than about once per week.
>>
>> This would not be a problem but for the fact that the BRAS profile stays
>> at around 1Mbits/sec, because it never has the required continuous
>> connection for more than 72 hours.
>>
>> How do we find out the cause of the line drop?
>>
>> We've tried:
>>
>> 1) router only connected to master socket, no phones whatever;
>>
>> 2) all electrical devices in the house (including hot water and central
>> heating) switched off (except the router itself, obviously.
>>
>> There is no noticeable noise on the voice line.
>>
>> Ideas, please?
>>
>> TIA
>>
>> --
>> Graham J
>>
>>
>
> Not easy, but "switched off" is not really satisfactory nowadays.
> "Unplugged" is what you need if you really want to eliminate you own house's
> contents. (Difficult with many central heating systems, I know)
>
> What are the attenuation figures?
>

At 5.5Mbps you know they are around 43dB

The real issue is that this sort of crap is almost impossible to
trace..normally one can say that its most likely to be at the consumer
end, as that's where the received signals are lowest, BUT it can be
elsewhere.

> PA
>
>

In message <4da8667e$0$2517$(E-Mail Removed)>, Graham J
<graham@invalid.?.invalid> writes
>Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
>distance from the exchange these are reasonable figures.
>
>Every day, at a random time between 05:30 and 07:00 the line drops, and
>immediately re-synchronises. Quite often this is at 30dB SNR margin and
>about 1Mbits/sec. If the router is rebooted a few hours later the speed and
>SNR margin are back to normal.
>
>There are occasional line drops at other times, and failures between 20:00
>and 23:00 do occur more than about once per week.
>
>This would not be a problem but for the fact that the BRAS profile stays at
>around 1Mbits/sec, because it never has the required continuous connection
>for more than 72 hours.
>
>How do we find out the cause of the line drop?
>
>We've tried:
>
>1) router only connected to master socket, no phones whatever;
>
>2) all electrical devices in the house (including hot water and central
>heating) switched off (except the router itself, obviously.
>
>There is no noticeable noise on the voice line.
>
>Ideas, please?
>
>TIA
>
Can you run routerstats on your particular router.

It might give you a clue as to the shape of the noise profile.

It sounds as if it is a burst of noise, long enough to allow the router
to resynch while it is occurring. The shape of the noise risetime (if
its very quick then something is switching on, if its slower????). The
length of time it is present and the shape of its disappearance (again v
quick = switched off again, slow decay ??)


--
Invalid

"Peter Able" <stuck@home> wrote in message
news:(E-Mail Removed) o.uk...
>
> "Graham J" <graham@invalid> wrote in message
> news:4da8667e$0$2517$(E-Mail Removed)...
>> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
>> distance from the exchange these are reasonable figures.
>>
>> Every day, at a random time between 05:30 and 07:00 the line drops, and
>> immediately re-synchronises. Quite often this is at 30dB SNR margin and
>> about 1Mbits/sec. If the router is rebooted a few hours later the speed
>> and SNR margin are back to normal.
>>
>> There are occasional line drops at other times, and failures between
>> 20:00 and 23:00 do occur more than about once per week.
>>
>> This would not be a problem but for the fact that the BRAS profile stays
>> at around 1Mbits/sec, because it never has the required continuous
>> connection for more than 72 hours.
>>
>> How do we find out the cause of the line drop?
>>
>> We've tried:
>>
>> 1) router only connected to master socket, no phones whatever;
>>
>> 2) all electrical devices in the house (including hot water and central
>> heating) switched off (except the router itself, obviously.
>>
>> There is no noticeable noise on the voice line.
>>
>> Ideas, please?
>>
>> TIA
>>
>> --
>> Graham J
>>
>>
>
> Not easy, but "switched off" is not really satisfactory nowadays.
> "Unplugged" is what you need if you really want to eliminate you own
> house's contents. (Difficult with many central heating systems, I know)
>
> What are the attenuation figures?

Between 48dB and 50dB

"Graham J" <graham@invalid> wrote in message
news:4da8b3f5$0$2509$(E-Mail Removed)...
>
> "Peter Able" <stuck@home> wrote in message
> news:(E-Mail Removed) o.uk...
>>
>> "Graham J" <graham@invalid> wrote in message
>> news:4da8667e$0$2517$(E-Mail Removed)...
>>> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
>>> distance from the exchange these are reasonable figures.
>>>
>>> Every day, at a random time between 05:30 and 07:00 the line drops, and
>>> immediately re-synchronises. Quite often this is at 30dB SNR margin and
>>> about 1Mbits/sec. If the router is rebooted a few hours later the speed
>>> and SNR margin are back to normal.
>>>
>>> There are occasional line drops at other times, and failures between
>>> 20:00 and 23:00 do occur more than about once per week.
>>>
>>> This would not be a problem but for the fact that the BRAS profile stays
>>> at around 1Mbits/sec, because it never has the required continuous
>>> connection for more than 72 hours.
>>>
>>> How do we find out the cause of the line drop?
>>>
>>> We've tried:
>>>
>>> 1) router only connected to master socket, no phones whatever;
>>>
>>> 2) all electrical devices in the house (including hot water and central
>>> heating) switched off (except the router itself, obviously.
>>>
>>> There is no noticeable noise on the voice line.
>>>
>>> Ideas, please?
>>>
>>> TIA
>>>
>>> --
>>> Graham J
>>>
>>>
>>
>> Not easy, but "switched off" is not really satisfactory nowadays.
>> "Unplugged" is what you need if you really want to eliminate you own
>> house's contents. (Difficult with many central heating systems, I know)
>>
>> What are the attenuation figures?
>
> Between 48dB and 50dB
>

Hmmm. That is quite a high Attenuation Figure for 5.5Mbps - or at least to
sustain 5.5Mbps 24 hours a day.

If you've performed tests with everything else in the house UNPLUGGED, as
suggested in the previous email, then you either need to find the external
noise source and negotiate with its owner, or - much easier - to try to
mitigate its effect upon your broadband service. One way to do the latter is
as follows:

The sustainable bit rate is a function of the router own noise algorithms
and of the connection speed it is trying to hold. Routers have different
ways of assessing signal-above-noise figures and so some are more likely to
give up the connection than others. The signal-above-noise figures vary
through each 24 hour (diurnal) cycle and the trick is to get the router to
connect at a speed that will mean it is best able to hold the connection 24
hours a day. My experience is that the biggest variable for lines that are
near to -50dB (my own is -52dB) in the diurnal cycle is the pick-up of
broadcast radio signals - which is worse from dusk to dawn. If I power down
the router at 2200 hours it reconnects at about 3000kbps/+6dB - but it is
then stable for ever. If I do the same thing at 0900 hours I connect at
close to 5000kbps/+6dB and later that evening it all crashes. The trick is
to find the hour at which a power-down, pause, power-up of the modem gives
you the optimum balance of speed and stability. In deciding this, by the
way, the breakpoints between different IP profiles should be taken into
account. For example, if your system can just about sustain 4500kbps 24
hours a day, you might as well shift it to 4100kbps by changing the
reconnect time - they both give exactly the same IP profile and 4100 will be
more stable than 4500. The IP profile breakpoints to beat around the rates
we are discussing are 4000bps, 4544kbps and 5120kbps,

As I've said, this is mitigation of the issue caused by the early-morning
problem you have, but mitigation is better tham frustration.

"Peter Able" <stuck@home> wrote in message
news:s-(E-Mail Removed)...
>
> "Graham J" <graham@invalid> wrote in message
> news:4da8b3f5$0$2509$(E-Mail Removed)...
>>
>> "Peter Able" <stuck@home> wrote in message
>> news:(E-Mail Removed) o.uk...
>>>
>>> "Graham J" <graham@invalid> wrote in message
>>> news:4da8667e$0$2517$(E-Mail Removed)...
>>>> Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given
>>>> the distance from the exchange these are reasonable figures.
>>>>
>>>> Every day, at a random time between 05:30 and 07:00 the line drops, and
>>>> immediately re-synchronises. Quite often this is at 30dB SNR margin
>>>> and about 1Mbits/sec. If the router is rebooted a few hours later the
>>>> speed and SNR margin are back to normal.
>>>>
>>>> There are occasional line drops at other times, and failures between
>>>> 20:00 and 23:00 do occur more than about once per week.
>>>>
>>>> This would not be a problem but for the fact that the BRAS profile
>>>> stays at around 1Mbits/sec, because it never has the required
>>>> continuous connection for more than 72 hours.
>>>>
>>>> How do we find out the cause of the line drop?
>>>>
>>>> We've tried:
>>>>
>>>> 1) router only connected to master socket, no phones whatever;
>>>>
>>>> 2) all electrical devices in the house (including hot water and central
>>>> heating) switched off (except the router itself, obviously.
>>>>
>>>> There is no noticeable noise on the voice line.
>>>>
>>>> Ideas, please?
>>>>
>>>> TIA
>>>>
>>>> --
>>>> Graham J
>>>>
>>>>
>>>
>>> Not easy, but "switched off" is not really satisfactory nowadays.
>>> "Unplugged" is what you need if you really want to eliminate you own
>>> house's contents. (Difficult with many central heating systems, I know)
>>>
>>> What are the attenuation figures?
>>
>> Between 48dB and 50dB
>>
>
> Hmmm. That is quite a high Attenuation Figure for 5.5Mbps - or at least to
> sustain 5.5Mbps 24 hours a day.
>
> If you've performed tests with everything else in the house UNPLUGGED, as
> suggested in the previous email, then you either need to find the external
> noise source and negotiate with its owner, or - much easier - to try to
> mitigate its effect upon your broadband service. One way to do the latter
> is as follows:
>
> The sustainable bit rate is a function of the router own noise algorithms
> and of the connection speed it is trying to hold. Routers have different
> ways of assessing signal-above-noise figures and so some are more likely
> to give up the connection than others. The signal-above-noise figures
> vary through each 24 hour (diurnal) cycle and the trick is to get the
> router to connect at a speed that will mean it is best able to hold the
> connection 24 hours a day. My experience is that the biggest variable for
> lines that are near to -50dB (my own is -52dB) in the diurnal cycle is the
> pick-up of broadcast radio signals - which is worse from dusk to dawn. If
> I power down the router at 2200 hours it reconnects at about
> 3000kbps/+6dB - but it is then stable for ever. If I do the same thing at
> 0900 hours I connect at close to 5000kbps/+6dB and later that evening it
> all crashes. The trick is to find the hour at which a power-down, pause,
> power-up of the modem gives you the optimum balance of speed and
> stability. In deciding this, by the way, the breakpoints between
> different IP profiles should be taken into account. For example, if your
> system can just about sustain 4500kbps 24 hours a day, you might as well
> shift it to 4100kbps by changing the reconnect time - they both give
> exactly the same IP profile and 4100 will be more stable than 4500. The
> IP profile breakpoints to beat around the rates we are discussing are
> 4000bps, 4544kbps and 5120kbps,
>
> As I've said, this is mitigation of the issue caused by the early-morning
> problem you have, but mitigation is better tham frustration.

I take your point. The router in normal use is an Edimax AR-7064g+A which
is noted for getting a high sync rate in the face of poor attenuation.

I have now installed an old Vigor 2600. This reports around 3488kbits/sec,
14 db SNR margin, and 46dB attenuation. The Vigor is noted for reducing
speed and raising SNR margin in order to retain a reliable connection.

The Vigor still suffers from the 05:30 to 07:00 noise problem, and drops to
1344 kbits/sec, 16dB SNR margin and 45.5 dB attenuation. It follows that
this leads to a BRAS profile about adsl1000. So to retain a reasonable BRAS
profile it's better to use the Edimax router because is usually syncs at
around 2000kbits/sec in the face of the noise burst.

Whatever the noise is, I've not found a router that will survive it. The
Vigor is there to allow syslog to capture the parameters.

--
Graham J

Graham J wrote:

> Whatever the noise is, I've not found a router that will survive it. The
> Vigor is there to allow syslog to capture the parameters.
>

well its fairly clear you are getting noise bursts.

These could be in your house, in an adjacent cable, in your cable, or in
the exchange.

So lets examine the possibilities.

In your house
=============
I suspect the use of two routers, using the faceplate, killing all other
apparatus etc. have ruled this out, but an AM radio on LW tuned between
stations is a good way to probe if you are around when the interference
is happening. If its by the actual phone wires, you will probably here
any crap, that's cable induced as well, alng with the broadband mush.


In the local loop
=================

The regular nature of the interference suggest to me its not a bad
joint, and if the lines is not exceptionally hissy as well, that tends
to rule that out.

If you report a broadband fault to the ISP and are firm about it then
tell the Openreach engineer the whole story, point out that you have
tried all that you have tried, and with luck, and tea and GOOD biscuits,
he will re-route you onto a different pair pretty much all the way back
to the exchange. If it is the local loop that should fix it.


In the exchange
===============

If that fails to solve it, the implication is its a faulty card or joint
in the exchange. All you can do here is, post the engineer visit, flag
with the ISP that the matter is not put to bed, and all they can do is
flag that with Openreach via BT wholesale. With luck they will monitor
your line, see that all the line and premises work has been done, and
replace a DSLAM card or remake the exchange joints. On two occasions I
have had crap speeds that 'magically' fixed themselves after being
reported, with no actual feedback from anyone, or even acknowledgement
that a problem existed.

My *guess* is that BT openreach know when they have backhaul
issues/DSLAM faults, but unless its total failure they don't reveal the
fact, for fear of having t pay compensation, but they do in time fix and
upgrade.

Likewise if the ISP is skimping on backhaul they won't tell you
either..but that won't show up as poor synch speeds.

Anyway, the pragmatic approach is absolutely to log everything, and give
your ISP a polite hard time.Insist that you have a real problem, and
show that you have done everything reasonable to ensure its not a
premises fault, and you want them to report it as a broadband fault to
BT wholesale/open reach. If they fuck you around, get a MAC code and a
new ISP, and explain to THEM why you are moving and what you want THEM
to do.

Finally, above all, realise that the people you deal with often do not
have the power to fix this for you: they are minions, and getting them
on your side so they can present your problems to their line management,
is more important than shouting at them, and bad mouthing the company
that employs them.

On Fri, 15 Apr 2011 19:34:27 +0100, Invalid
<(E-Mail Removed)> wrote:

>In message <4da8667e$0$2517$(E-Mail Removed)>, Graham J
><graham@invalid.?.invalid> writes
>>Router normally reports 6dbSNR margin and about 5.5Mbits/sec. Given the
>>distance from the exchange these are reasonable figures.
>>
>>Every day, at a random time between 05:30 and 07:00 the line drops, and
>>immediately re-synchronises. Quite often this is at 30dB SNR margin and
>>about 1Mbits/sec. If the router is rebooted a few hours later the speed and
>>SNR margin are back to normal.
>>
>>There are occasional line drops at other times, and failures between 20:00
>>and 23:00 do occur more than about once per week.
>>
>>This would not be a problem but for the fact that the BRAS profile stays at
>>around 1Mbits/sec, because it never has the required continuous connection
>>for more than 72 hours.
>>
>>How do we find out the cause of the line drop?
>>
>>We've tried:
>>
>>1) router only connected to master socket, no phones whatever;
>>
>>2) all electrical devices in the house (including hot water and central
>>heating) switched off (except the router itself, obviously.
>>
>>There is no noticeable noise on the voice line.
>>
>>Ideas, please?
>>
>>TIA
>>
>Can you run routerstats on your particular router.
>
>It might give you a clue as to the shape of the noise profile.
>
>It sounds as if it is a burst of noise, long enough to allow the router
>to resynch while it is occurring.

That would be my guess too.

>The shape of the noise risetime (if
>its very quick then something is switching on, if its slower????). The
>length of time it is present and the shape of its disappearance (again v
>quick = switched off again, slow decay ??)

I doubt anything switching on or off would create interference that
would still be strong when the router tries to resync.

Report the fault to your ISP. Do all the tests they tell you to do
(if you haven't already done them) and be persistent.
--
(\__/) M.
(='.'=) Due to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking some articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.