SNR levels?

I wonder if someone knowledgeable in ADSL technology could give me
some advice please?

I have been experiencing loss of sync on my ADSL (512/256) for some
time. The period between dropouts would vary between a few minutes
to 4 hours or more.
I raised the problem with my ISP who in turn escalated it to BT who
said there was a fault on my line. A BT engineer called to say the
fault had been corrected a short time ago, and I am monitoring the
situation (OK so far!).

My question regarding SNR levels is that, when I was having
dropouts, the Downstream levels varied hugely from as poor as 8 to
as good as 32dB. Normally it is around 15dB. Attenuation varied
less widely, at around 45 to 55dB. Now that the fault is
(supposedly) fixed, the SNR levels are still showing quite large
variations from minute-to-minute (as reported by my modem/router).
The Upstream levels remain constant.

Is this continual variation of Downstream SNR levels 'normal' for
ADSL or should it be fairly constant? What affects SNR levels?

Many thanks,

Al

NTL Binary wrote:
> I wonder if someone knowledgeable in ADSL technology could give me
> some advice please?
>
> I have been experiencing loss of sync on my ADSL (512/256) for some
> time. The period between dropouts would vary between a few minutes
> to 4 hours or more.
> I raised the problem with my ISP who in turn escalated it to BT who
> said there was a fault on my line. A BT engineer called to say the
> fault had been corrected a short time ago, and I am monitoring the
> situation (OK so far!).
>
> My question regarding SNR levels is that, when I was having
> dropouts, the Downstream levels varied hugely from as poor as 8 to
> as good as 32dB. Normally it is around 15dB. Attenuation varied
> less widely, at around 45 to 55dB. Now that the fault is
> (supposedly) fixed, the SNR levels are still showing quite large
> variations from minute-to-minute (as reported by my modem/router).
> The Upstream levels remain constant.
>
> Is this continual variation of Downstream SNR levels 'normal' for
> ADSL or should it be fairly constant? What affects SNR levels?
>
SNR values will/can/normally fluctuate during the day but only slowly,
normally getting worse as the evening draws in, but in some cases it can get
better. The way you describe it it is as if it going up & down like a yoyo
which isn't normal.....

Having said that if you are not losing connection I wouldn't worry to much.

A quick 'dirty' check would be for you to disconnect the bell wire (pin 3)
on all your sockets & see if that makes any difference as that can act as an
aerial & pick up all sorts of strange & wonderful things with detriment to
your ADSL.

I said normally as for some reason mine doesn't but I've only had the
oppotunity to play/abuse this DSL service for a short time so I may notice
some changes as time goes on...

"Kráftéé" <(E-Mail Removed)> wrote in message
news:4139fd99$0$47326$(E-Mail Removed)...
> SNR values will/can/normally fluctuate during the day but only slowly,
> normally getting worse as the evening draws in, but in some cases it can
> get better. The way you describe it it is as if it going up & down like a
> yoyo which isn't normal.....
>
> Having said that if you are not losing connection I wouldn't worry to
> much.
>
> A quick 'dirty' check would be for you to disconnect the bell wire (pin 3)
> on all your sockets & see if that makes any difference as that can act as
> an aerial & pick up all sorts of strange & wonderful things with detriment
> to your ADSL.
>
> I said normally as for some reason mine doesn't but I've only had the
> oppotunity to play/abuse this DSL service for a short time so I may notice
> some changes as time goes on...
Thanks for your reply - you are correct in saying the SNR is going up and
down constantly (like a yoyo ;-) ) jumping from, say, 9.8 to 15.4 to 27.3
and varying between those limits all the time.

The problem is that I *do* lose the connection (sync) - it is
re-established, usually, very quickly but if I am d/l anything on p2p etc.
it is long enough to stop all transfers which is extremely frustrating.
These disconnects can be as frequent as every few minutes, or as long as 4
hours, averaging out at about 1.5 hours. My ISP has been as helpful as it
can, and BT supposedly fixed a line fault today, but the problem of frequent
disconnections persists.

I am getting so frustrated that I'm ready to ditch ADSL (and BT) and stay
with NTL which, at least here, is rock solid, and has been for some years. I
have been testing ADSL with PlusNet for some months and would prefer to
change to ADSL as my permanent connection for a number of reasons, (no cap,
better upload bandwidth, excellent support, etc.) but the above problem
seems to make this less and less likely. ;-(

Al

"Al" <(E-Mail Removed)> wrote in message
news:413a09fe$0$95768$(E-Mail Removed)...
>
> "Kráftéé" <(E-Mail Removed)> wrote in message
> news:4139fd99$0$47326$(E-Mail Removed)...
>> SNR values will/can/normally fluctuate during the day but only slowly,
>> normally getting worse as the evening draws in, but in some cases it can
>> get better. The way you describe it it is as if it going up & down like
>> a yoyo which isn't normal.....
>>
>> Having said that if you are not losing connection I wouldn't worry to
>> much.
>>
>> A quick 'dirty' check would be for you to disconnect the bell wire (pin
>> 3) on all your sockets & see if that makes any difference as that can act
>> as an aerial & pick up all sorts of strange & wonderful things with
>> detriment to your ADSL.
>>
>> I said normally as for some reason mine doesn't but I've only had the
>> oppotunity to play/abuse this DSL service for a short time so I may
>> notice some changes as time goes on...
> Thanks for your reply - you are correct in saying the SNR is going up and
> down constantly (like a yoyo ;-) ) jumping from, say, 9.8 to 15.4 to 27.3
> and varying between those limits all the time.
>
> The problem is that I *do* lose the connection (sync) - it is
> re-established, usually, very quickly but if I am d/l anything on p2p etc.
> it is long enough to stop all transfers which is extremely frustrating.
> These disconnects can be as frequent as every few minutes, or as long as 4
> hours, averaging out at about 1.5 hours. My ISP has been as helpful as it
> can, and BT supposedly fixed a line fault today, but the problem of
> frequent disconnections persists.
>
> I am getting so frustrated that I'm ready to ditch ADSL (and BT) and stay
> with NTL which, at least here, is rock solid, and has been for some years.
> I have been testing ADSL with PlusNet for some months and would prefer to
> change to ADSL as my permanent connection for a number of reasons, (no
> cap, better upload bandwidth, excellent support, etc.) but the above
> problem seems to make this less and less likely. ;-(
>
> Al
Hi Al. I had a similar problem recently and after much messing about trying
to isolate which extension wire could be causing it, I fitted an NTE-2005
Master Face Plate that results in my ADSL connection only "seeing" the noise
on the incoming line and not the noise from the extension wiring. My SNR
varied between 10 and 21db and now it is a solid 32db. Still see a few CRC
errors though.

Rgds
Alec




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"Alec" <(E-Mail Removed)> wrote in message
news:413a10b6$0$20247$(E-Mail Removed)...
>
> "Al" <(E-Mail Removed)> wrote in message
> news:413a09fe$0$95768$(E-Mail Removed)...
> >
> > "Kráftéé" <(E-Mail Removed)> wrote in
message
> > news:4139fd99$0$47326$(E-Mail Removed)...
> >> SNR values will/can/normally fluctuate during the day but only
slowly,
> >> normally getting worse as the evening draws in, but in some
cases it can
> >> get better. The way you describe it it is as if it going up &
down like
> >> a yoyo which isn't normal.....
> >>
> >> Having said that if you are not losing connection I wouldn't
worry to
> >> much.
> >>
> >> A quick 'dirty' check would be for you to disconnect the bell
wire (pin
> >> 3) on all your sockets & see if that makes any difference as
that can act
> >> as an aerial & pick up all sorts of strange & wonderful things
with
> >> detriment to your ADSL.
> >>
> >> I said normally as for some reason mine doesn't but I've only
had the
> >> oppotunity to play/abuse this DSL service for a short time so
I may
> >> notice some changes as time goes on...
> > Thanks for your reply - you are correct in saying the SNR is
going up and
> > down constantly (like a yoyo ;-) ) jumping from, say, 9.8 to
15.4 to 27.3
> > and varying between those limits all the time.
> >
> > The problem is that I *do* lose the connection (sync) - it is
> > re-established, usually, very quickly but if I am d/l anything
on p2p etc.
> > it is long enough to stop all transfers which is extremely
frustrating.
> > These disconnects can be as frequent as every few minutes, or
as long as 4
> > hours, averaging out at about 1.5 hours. My ISP has been as
helpful as it
> > can, and BT supposedly fixed a line fault today, but the
problem of
> > frequent disconnections persists.
> >
> > I am getting so frustrated that I'm ready to ditch ADSL (and
BT) and stay
> > with NTL which, at least here, is rock solid, and has been for
some years.
> > I have been testing ADSL with PlusNet for some months and would
prefer to
> > change to ADSL as my permanent connection for a number of
reasons, (no
> > cap, better upload bandwidth, excellent support, etc.) but the
above
> > problem seems to make this less and less likely. ;-(
> >
> > Al
> Hi Al. I had a similar problem recently and after much messing
about trying
> to isolate which extension wire could be causing it, I fitted an
NTE-2005
> Master Face Plate that results in my ADSL connection only
"seeing" the noise
> on the incoming line and not the noise from the extension wiring.
My SNR
> varied between 10 and 21db and now it is a solid 32db. Still see
a few CRC
> errors though.
>
Hi Alec

Thanks for that - I will definitely try your suggestion. Are
NTE-2005s readily available?

To be honest, I have thought it *may* be an internal wiring
problem, and like you have done a bit of messing about, but not
solved anything. Does the NTE-2005 replace the standard BT
faceplate? Does any extension wiring after that not affect the SNR?
The master is in the hall and the 'computer room' is upstairs and
so requires a long-ish extension wire.

Regards,

Al

NTL Binary wrote:
> "Alec" <(E-Mail Removed)> wrote in message
> news:413a10b6$0$20247$(E-Mail Removed)...
>>
>> "Al" <(E-Mail Removed)> wrote in message
>> news:413a09fe$0$95768$(E-Mail Removed)...
>>>
>>> "Kráftéé" <(E-Mail Removed)> wrote in
>>> message
>>> news:4139fd99$0$47326$(E-Mail Removed)...
>>>> SNR values will/can/normally fluctuate during the day but only
>>>> slowly, normally getting worse as the evening draws in, but in
>>>> some cases it can get better. The way you describe it it is as
>>>> if it going up & down like a yoyo which isn't normal.....
>>>>
>>>> Having said that if you are not losing connection I wouldn't
>>>> worry to much.
>>>>
>>>> A quick 'dirty' check would be for you to disconnect the bell
>>>> wire (pin 3) on all your sockets & see if that makes any
>>>> difference as that can act as an aerial & pick up all sorts of
>>>> strange & wonderful things with detriment to your ADSL.
>>>>
>>>> I said normally as for some reason mine doesn't but I've only
>>>> had the oppotunity to play/abuse this DSL service for a short
>>>> time so I may notice some changes as time goes on...
>>> Thanks for your reply - you are correct in saying the SNR is
>>> going up and down constantly (like a yoyo ;-) ) jumping from,
>>> say, 9.8 to 15.4 to 27.3 and varying between those limits all the
>>> time.
>>>
>>> The problem is that I *do* lose the connection (sync) - it is
>>> re-established, usually, very quickly but if I am d/l anything on
>>> p2p etc. it is long enough to stop all transfers which is
>>> extremely frustrating. These disconnects can be as frequent as
>>> every few minutes, or as long as 4 hours, averaging out at about
>>> 1.5 hours. My ISP has been as helpful as it can, and BT
>>> supposedly fixed a line fault today, but the problem of frequent
>>> disconnections persists.
>>>
>>> I am getting so frustrated that I'm ready to ditch ADSL (and BT)
>>> and stay with NTL which, at least here, is rock solid, and has
>>> been for some years. I have been testing ADSL with PlusNet for
>>> some months and would prefer to change to ADSL as my permanent
>>> connection for a number of reasons, (no cap, better upload
>>> bandwidth, excellent support, etc.) but the above problem seems
>>> to make this less and less likely. ;-(
>>>
>>> Al
>> Hi Al. I had a similar problem recently and after much messing
>> about trying to isolate which extension wire could be causing it,
>> I fitted an NTE-2005 Master Face Plate that results in my ADSL
>> connection only "seeing" the noise on the incoming line and not
>> the noise from the extension wiring. My SNR varied between 10 and
>> 21db and now it is a solid 32db. Still see a few CRC errors though.
>>
> Hi Alec
>
> Thanks for that - I will definitely try your suggestion. Are
> NTE-2005s readily available?
>
> To be honest, I have thought it *may* be an internal wiring
> problem, and like you have done a bit of messing about, but not
> solved anything. Does the NTE-2005 replace the standard BT
> faceplate? Does any extension wiring after that not affect the SNR?
> The master is in the hall and the 'computer room' is upstairs and
> so requires a long-ish extension wire.
>
> Regards,
>
> Al

Which is why I suggested you disconnect the bell wire in the first place.
If it does make a difference (which it could/should/may as the bell wire
acts as an aeriel) then you have a choice to make but if you don't then you
are still in the dark.

By the way the phones should still ring if you have good filters fitted...

"Kráftéé" <(E-Mail Removed)> wrote in
message
news:413a24d4$0$73525$(E-Mail Removed)...
> NTL Binary wrote:
> > "Alec" <(E-Mail Removed)> wrote in message
> > news:413a10b6$0$20247$(E-Mail Removed)...
> >>
> >> "Al" <(E-Mail Removed)> wrote in message
> >> news:413a09fe$0$95768$(E-Mail Removed)...
> >>>
> >>> "Kráftéé" <(E-Mail Removed)> wrote
in
> >>> message
> >>>
news:4139fd99$0$47326$(E-Mail Removed)...
> >>>> SNR values will/can/normally fluctuate during the day but
only
> >>>> slowly, normally getting worse as the evening draws in,
but in
> >>>> some cases it can get better. The way you describe it it
is as
> >>>> if it going up & down like a yoyo which isn't normal.....
> >>>>
> >>>> Having said that if you are not losing connection I
wouldn't
> >>>> worry to much.
> >>>>
> >>>> A quick 'dirty' check would be for you to disconnect the
bell
> >>>> wire (pin 3) on all your sockets & see if that makes any
> >>>> difference as that can act as an aerial & pick up all
sorts of
> >>>> strange & wonderful things with detriment to your ADSL.
> >>>>
> >>>> I said normally as for some reason mine doesn't but I've
only
> >>>> had the oppotunity to play/abuse this DSL service for a
short
> >>>> time so I may notice some changes as time goes on...
> >>> Thanks for your reply - you are correct in saying the SNR
is
> >>> going up and down constantly (like a yoyo ;-) ) jumping
from,
> >>> say, 9.8 to 15.4 to 27.3 and varying between those limits
all the
> >>> time.
> >>>
> >>> The problem is that I *do* lose the connection (sync) - it
is
> >>> re-established, usually, very quickly but if I am d/l
anything on
> >>> p2p etc. it is long enough to stop all transfers which is
> >>> extremely frustrating. These disconnects can be as frequent
as
> >>> every few minutes, or as long as 4 hours, averaging out at
about
> >>> 1.5 hours. My ISP has been as helpful as it can, and BT
> >>> supposedly fixed a line fault today, but the problem of
frequent
> >>> disconnections persists.
> >>>
> >>> I am getting so frustrated that I'm ready to ditch ADSL
(and BT)
> >>> and stay with NTL which, at least here, is rock solid, and
has
> >>> been for some years. I have been testing ADSL with PlusNet
for
> >>> some months and would prefer to change to ADSL as my
permanent
> >>> connection for a number of reasons, (no cap, better upload
> >>> bandwidth, excellent support, etc.) but the above problem
seems
> >>> to make this less and less likely. ;-(
> >>>
> >>> Al
> >> Hi Al. I had a similar problem recently and after much
messing
> >> about trying to isolate which extension wire could be
causing it,
> >> I fitted an NTE-2005 Master Face Plate that results in my
ADSL
> >> connection only "seeing" the noise on the incoming line and
not
> >> the noise from the extension wiring. My SNR varied between
10 and
> >> 21db and now it is a solid 32db. Still see a few CRC errors
though.
> >>
> > Hi Alec
> >
> > Thanks for that - I will definitely try your suggestion. Are
> > NTE-2005s readily available?
> >
> > To be honest, I have thought it *may* be an internal wiring
> > problem, and like you have done a bit of messing about, but
not
> > solved anything. Does the NTE-2005 replace the standard BT
> > faceplate? Does any extension wiring after that not affect
the SNR?
> > The master is in the hall and the 'computer room' is upstairs
and
> > so requires a long-ish extension wire.
> >
> > Regards,
> >
> > Al
>
> Which is why I suggested you disconnect the bell wire in the
first place.
> If it does make a difference (which it could/should/may as the
bell wire
> acts as an aeriel) then you have a choice to make but if you
don't then you
> are still in the dark.
>
> By the way the phones should still ring if you have good
filters fitted...
>
>

Ah - I did check and there is no bell wire connected (only two
wires in the master socket). The connection is currently used for
ADSL only - no phones, extension sockets or other equipment
connected. Just have a micro-filter (good quality one - and I've
tried several) fitted to the BT master socket and an RJ11
extension cable up to the computer - nothing else!

Thanks for your suggestions.

Al

"NTL Binary" <(E-Mail Removed)> wrote in message
news:TSo_c.349$(E-Mail Removed)...
> "Alec" <(E-Mail Removed)> wrote in message
> news:413a10b6$0$20247$(E-Mail Removed)...
>>
>> "Al" <(E-Mail Removed)> wrote in message
>> news:413a09fe$0$95768$(E-Mail Removed)...
>> >
>> > "Kráftéé" <(E-Mail Removed)> wrote in
> message
>> > news:4139fd99$0$47326$(E-Mail Removed)...
>> >> SNR values will/can/normally fluctuate during the day but only
> slowly,
>> >> normally getting worse as the evening draws in, but in some
> cases it can
>> >> get better. The way you describe it it is as if it going up &
> down like
>> >> a yoyo which isn't normal.....
>> >>
>> >> Having said that if you are not losing connection I wouldn't
> worry to
>> >> much.
>> >>
>> >> A quick 'dirty' check would be for you to disconnect the bell
> wire (pin
>> >> 3) on all your sockets & see if that makes any difference as
> that can act
>> >> as an aerial & pick up all sorts of strange & wonderful things
> with
>> >> detriment to your ADSL.
>> >>
>> >> I said normally as for some reason mine doesn't but I've only
> had the
>> >> oppotunity to play/abuse this DSL service for a short time so
> I may
>> >> notice some changes as time goes on...
>> > Thanks for your reply - you are correct in saying the SNR is
> going up and
>> > down constantly (like a yoyo ;-) ) jumping from, say, 9.8 to
> 15.4 to 27.3
>> > and varying between those limits all the time.
>> >
>> > The problem is that I *do* lose the connection (sync) - it is
>> > re-established, usually, very quickly but if I am d/l anything
> on p2p etc.
>> > it is long enough to stop all transfers which is extremely
> frustrating.
>> > These disconnects can be as frequent as every few minutes, or
> as long as 4
>> > hours, averaging out at about 1.5 hours. My ISP has been as
> helpful as it
>> > can, and BT supposedly fixed a line fault today, but the
> problem of
>> > frequent disconnections persists.
>> >
>> > I am getting so frustrated that I'm ready to ditch ADSL (and
> BT) and stay
>> > with NTL which, at least here, is rock solid, and has been for
> some years.
>> > I have been testing ADSL with PlusNet for some months and would
> prefer to
>> > change to ADSL as my permanent connection for a number of
> reasons, (no
>> > cap, better upload bandwidth, excellent support, etc.) but the
> above
>> > problem seems to make this less and less likely. ;-(
>> >
>> > Al
>> Hi Al. I had a similar problem recently and after much messing
> about trying
>> to isolate which extension wire could be causing it, I fitted an
> NTE-2005
>> Master Face Plate that results in my ADSL connection only
> "seeing" the noise
>> on the incoming line and not the noise from the extension wiring.
> My SNR
>> varied between 10 and 21db and now it is a solid 32db. Still see
> a few CRC
>> errors though.
>>
> Hi Alec
>
> Thanks for that - I will definitely try your suggestion. Are
> NTE-2005s readily available?
>
> To be honest, I have thought it *may* be an internal wiring
> problem, and like you have done a bit of messing about, but not
> solved anything. Does the NTE-2005 replace the standard BT
> faceplate? Does any extension wiring after that not affect the SNR?
> The master is in the hall and the 'computer room' is upstairs and
> so requires a long-ish extension wire.
>
> Regards,
>
> Al
Find it here:
http://www.adslnation.com/phpapps/ca...products_id=90



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On Sat, 04 Sep 2004 21:14:24 GMT, "NTL Binary" <(E-Mail Removed)>
wrote:


>Ah - I did check and there is no bell wire connected (only two
>wires in the master socket). The connection is currently used for
>ADSL only - no phones, extension sockets or other equipment
>connected. Just have a micro-filter (good quality one - and I've
>tried several) fitted to the BT master socket and an RJ11
>extension cable up to the computer - nothing else!

Ummm why have you got a microfilter fitted if there's no POTS
equipment in use? If the connection is only for ADSL then you don't
need a microfilter - unplug it and see what happens.
--
John Naismith

"John Naismith" <john$(E-Mail Removed)> wrote in message
news:(E-Mail Removed)
> On Sat, 04 Sep 2004 21:14:24 GMT, "NTL Binary" <(E-Mail Removed)>
> wrote:
>
>
>> Ah - I did check and there is no bell wire connected (only two
>> wires in the master socket). The connection is currently used for
>> ADSL only - no phones, extension sockets or other equipment
>> connected. Just have a micro-filter (good quality one - and I've
>> tried several) fitted to the BT master socket and an RJ11
>> extension cable up to the computer - nothing else!
>
> Ummm why have you got a microfilter fitted if there's no POTS
> equipment in use? If the connection is only for ADSL then you don't
> need a microfilter - unplug it and see what happens.

But you will then need a modem cable to connect to the POTS socket.

--
Old Codger
e-mail use reply to field

What matters in politics is not what happens, but what you can make people
believe has happened. [Janet Daley 27/8/2003]