Help sought in identifying loss-of-sync problem

Hello

Please could someone take a look at these fault-finding steps I've taken, so
I can get a second opinion on where the fault lies? I am sure it is either
the BT line having degraded or something inside my house which I am trying
to identify via the following discourse:

1) My ADSL and telephone setup has remained unchanged and working fine for
many months - until yesterday when my router (3Com) sync light extinguished.
Rebooting the router didn't help - I would see the sync light come on and go
off a few times as the router tried to negotiate setting with the DSLAM, but
ultimately it gives up and I am left with an unsync'd router.

2) If I plug the router directly into the master socket (MS) with nothing
else connected, I get sync and it all works fine. (HTTP/POP3/SMTP/NNTP - all
working).

3) If I plug into the MS via an ADSL microfilter, I get sync and it all
works fine.

4) If I plug a metre of BT telephone cable into the "phone" port of the
microfilter and leave the router connected still via the microfilter
straight into the MS , I lose sync.

5) If I then terminate that 1m flying lead with a phone, I lose sync.

6) If I change the microfilter I get the same responses as 3-5 above

7) If I change the BT flying lead to a different one , I still lose sync.

8) The phone works fine when connected via the microfilter or direct to the
MS, irrespective of whether the router is connected or not.


Observations:
A) I only have a master socket which is maybe 2m from the BT riser into the
house. My phone and router then plugged into it, via a microfilter, and all
was well. There are no extension sockets.


My conclusion:
the microfilters are both OK as is the cabling inside the house, as is the
router. However, the external line to the property has become
damaged/waterlogged, such that the REN support capability of the line has
degraded. Loading the line with more than just the router causes the SNR on
the line to drop such that the router cannot negotiate its noise
environment.

What do I do next?
1) Try a different phone - mine is a DECT phone which although it has a REN
of 1, may have developed a fault such that its REN equivalence has
increased.
2) Get BT to test the line - the fault has been reported via my ISP
3)? Any suggestions anyone please?

My router is reporting the following operating conditions when it is synced
(clearly I can't get it to report when it is not synced - the router
diagnostics page just says "disconnected" and no specs are given for SNR
etc.):

Operation Data Upstream Downstream
Noise Margin 30 dB 9.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 38 dB

Cheers for any pointers

RMC, England

> My router is reporting the following operating conditions when it is
> synced (clearly I can't get it to report when it is not synced - the
> router diagnostics page just says "disconnected" and no specs are given
> for SNR etc.):
>
> Operation Data Upstream Downstream
> Noise Margin 30 dB 9.5 dB
> Output Power 10.5 dBm 20 dBm
> Attenuation 20.5 dB 38 dB

I note that if I interrogate the router immediately after conecting a
phonelead or phonelead with telephone, I get the following figures in the
20-30s it takes before I lose connectivity:

Operation Data Upstream Downstream
Noise Margin 30 dB 5.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 38 dB

and then

Operation Data Upstream Downstream
Noise Margin 29 dB -7.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 37 dB

The downstream margin drops from 9.5 to 5.5 to -7.5 dB! Clearly some form of
line loading is in force - either due to my phone having developed a fault
or the line impedance altering due to the environment. looks like I need to
find another landline phone to test against.

Cheers

RMC, England

>> My router is reporting the following operating conditions when it is
>> synced (clearly I can't get it to report when it is not synced - the
>> router diagnostics page just says "disconnected" and no specs are given
>> for SNR etc.):

If you have a 3COM modem get hold of a different power supply and try
it. I've been through five 3COM power supplies in the last 6 months.
They generally fail completely but I did have one that was creating a
lot of electrical noise giving all sorts of connection problems.

Good luck!

Regards
Barry

"Barry" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>>> My router is reporting the following operating conditions when it
>>> is synced (clearly I can't get it to report when it is not
>>> synced - the router diagnostics page just says "disconnected" and
>>> no specs are given for SNR etc.):
>
> If you have a 3COM modem get hold of a different power supply and
> try it. I've been through five 3COM power supplies in the last 6
> months. They generally fail completely but I did have one that was
> creating a lot of electrical noise giving all sorts of connection
> problems.
>
> Good luck!
>
Don't buy Belkin they can be even worse.

Get a small AM radio & tune it to around 612Khz & see if there is any
difference in signals heard with the power supply on & then off. You
may get a nasty surprise.

Only last week I found a Freeview set top box at one house & a plug
wart power supply for a USB hub in another, busy pushing out signals &
causing problems with the end users ADSL service.

"RMC" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hello
>
> Please could someone take a look at these fault-finding steps I've taken,
> so I can get a second opinion on where the fault lies? I am sure it is
> either the BT line having degraded or something inside my house which I am
> trying to identify via the following discourse:
>
> 1) My ADSL and telephone setup has remained unchanged and working fine for
> many months - until yesterday when my router (3Com) sync light
> extinguished.

Did you hang up your Christmas decorations yesterday ?

There are known problems with some tree lights causing loss of synch...

HTH, Ali

Barry, kráftéé and Zomaar

> Please could someone take a look at these fault-finding steps ?

Thanks for your replies and encouragement. I will look into PSU issues in
case the original supply has started radiating noise - if I can find a
linear one that'll do as a proof-of-concept check. I'll get onto that. The
suggestion re: extraneous equipment being a source of interference is also a
good one - we don't have any Xmas lights up yet and our neighbours are
similarly miserable so far!

One thing I have since observed is that, even when I do get sync and a
working connection, the speed is down to something like 180kbps instead of
1800 kbps - I'm on a 2Mbps fixed rate DSL line (should be, anyway!)

Cheers

RMC, England

RMC wrote:
> Barry, kráftéé and Zomaar
>
>> Please could someone take a look at these fault-finding steps ?
>
> Thanks for your replies and encouragement. I will look into PSU
> issues in case the original supply has started radiating noise - if
> I
> can find a linear one that'll do as a proof-of-concept check. I'll
> get onto that. The suggestion re: extraneous equipment being a
> source
> of interference is also a good one - we don't have any Xmas lights
> up yet and our neighbours are similarly miserable so far!
>
> One thing I have since observed is that, even when I do get sync and
> a
> working connection, the speed is down to something like 180kbps
> instead of 1800 kbps - I'm on a 2Mbps fixed rate DSL line (should
> be,
> anyway!)
> Cheers
>
> RMC, England

Can you check for errors?

>> Barry, kráftéé and Zomaar
>>> Please could someone take a look at these fault-finding steps ?

> Can you check for errors?

That's a good point - I didn't think of that. The error page says the
following (which I don't understand):

Indicator Name Near End Indicator
Far End Indicator
Fast Path FEC Correction 0
1
Interleaved Path FEC Correction 0
0
Fast Path CRC Error 14852
0
Interleaved Path CRC Error 0
0
Loss of Signal
---
Loss of Frame
---
Loss of Power
---
Fast Path HEC Error 1618
1618
Interleaved Path HEC Error 0
1



I don't know if that's good or bad. Can you comment on them for me please?

What I do know is that it is becoming increasingly difficult for me to gain
sync when the router is connected (nothig else connected) which suggests a
deteriorating line condition. My download rates are less than a tenth of
expected still and they may be slowing yet further (not enough test data to
mean anything yet).

Cheers

RMC, England

"RMC" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>
>>> Barry, kráftéé and Zomaar
>>>> Please could someone take a look at these fault-finding steps ?
>
>> Can you check for errors?
>
> That's a good point - I didn't think of that. The error page says
> the following (which I don't understand):
>
> Indicator Name Near End Indicator Far
> End Indicator
> Fast Path FEC Correction 0 1
> Interleaved Path FEC Correction 0 0
> Fast Path CRC Error 14852 0
> Interleaved Path CRC Error 0 0
> Loss of Signal ---
> Loss of Frame ---
> Loss of Power ---
> Fast Path HEC Error 1618 1618
> Interleaved Path HEC Error 0 1
>
>
>
> I don't know if that's good or bad. Can you comment on them for me
> please?
>
> What I do know is that it is becoming increasingly difficult for me
> to gain sync when the router is connected (nothig else connected)
> which suggests a deteriorating line condition. My download rates
> are less than a tenth of expected still and they may be slowing yet
> further (not enough test data to mean anything yet).
>
> Cheers
>

Time period????

>>> Can you check for errors?

>> That's a good point:

>> Fast Path CRC Error 14852 0
>> Fast Path HEC Error 1618 1618
>> Interleaved Path HEC Error 0 1

> Time period????

These results were obtained once sync had occurred and the router had
negotiated a successful connection - something like 2 - 3 minutes I would
guess. The errors mounted up when I did a few refreshes over the next few
minutes, but then the sync failed again and this is the first time I've been
back online since my earlier post.

RMC, England