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Author Topic: Very erratic ADSL connection  (Read 2492 times)

mje_uk

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Very erratic ADSL connection
« on: August 08, 2011, 06:01:39 PM »

My ADSL connection has become very erratic over the past couple of months (I have stored Routerstats output for the last month or so.)
I live some distance from the exchange with an LLU connection and a DG834PN router, showing : Attn Down/Up = 51/27 dB.
The line appears to resynch every hour or two (when I lose connection which is annoying for ADSL radio listening) for much of the time, but occasionally the performance is excellent. For example a week ago it ran all day at 4200/830kb not dropping to about 3000/64kb until the evening.
Currently (an averagely bad day) it is running and resynching every hour or two at around about :
Connect Rate 3424/96kb
Noise margin  8.5/8.0dB
HEC  639/5
ES  25426/0
Severe ES 372/0  ..... measured over WAN uptime (from SF counts) of 27 minutes
Interleave depth is 1/1 but I note that upstream interleaving sometimes switches on briefly when it tries to resynch. Hence I assume that my ISP (T-T) has set interleave to "auto".
When things are bad I notice that picking up the phone (either for outgoing or incoming call) the SNR margin downstream can improve from around 9 to 12dB. But the filter is good (ADSL Nation) and have tried many others.
If I reboot the router, then resynching keeps taking place usually until the upstream rate has sunk to about 96Kb. This happens with relatively little lowering of the downstream rate, and little change to any noise margins. Things stabilise often at around 96Kb upstream.
I have tried all the usual thing such as disconnecting all internal wiring etc etc, and can detect no correlation to any other electrical activity in house or time of day (except things are usually better at w/e).  I have an i-Plate on the master socket. Complaining to my ISP has resulted in the line being "reconfigured" but with little noticable improvement.

Does anyone please have any advice about what I should I do ??? I would probably get more helpful response from another ISP, but that is another matter.

Thanks very much

mje_uk
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jeffbb

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Re: Very erratic ADSL connection
« Reply #1 on: August 08, 2011, 06:18:02 PM »

Hi and welcome
quote :When things are bad I notice that picking up the phone (either for outgoing or incoming call) the SNR margin downstream can improve from around 9 to 12dB
This could be an indication of a bad joint  the higher current may be making a better connection * so your ADSL  gains SNR,
with your attenuation at the nominal 6db SNR margin you could expect to synch at about 4736Kbps.

Have you tried connecting directly to the test socket ?

Regards Jeff
* Perhaps  Razpag can comment  :)
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razpag

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Re: Very erratic ADSL connection
« Reply #2 on: August 08, 2011, 06:38:19 PM »

Nothing to comment on Jeff. You've basically summed it up mate.

Just to add something to the thread, I would do as Jeff asks, re testing at the Master, then ring your SP and get an engineer to visit. Please, please, please, ask the SP's front desk advisor to input notes stipulating 'Connection improves when phone receiver is lifted', or words to that effect. It means a lot to us guys. :)
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mje_uk

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Re: Very erratic ADSL connection
« Reply #3 on: August 08, 2011, 06:57:53 PM »

Thanks for those comments :

1) No, I have not tried connecting directly to the test socket. Maybe I'm being dim but, as I find no effect when I remove all internal wiring (which is all plugged into the master socket, i.e. I have no hardwired internal wiring), then I don't see how connecting to the test socket does anything (except bypass the iPlate). Obviously I'm missing something.
2) When lifting the phone, and things are bad, the SNR margin jumps by about 3dB on the downstream, but is unchanged on the upstream. I forgot to say that it takes about 10/15 mins after replacing the receiver for the noise margin to fall back to what it was before the call.
3) Do my error rates look unusually high ... I have no idea ?

Thanks again

mje_uk
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jeffbb

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Re: Very erratic ADSL connection
« Reply #4 on: August 08, 2011, 07:21:47 PM »

Hi
quote : Maybe I'm being dim but, as I find no effect when I remove all internal wiring (which is all plugged into the master socket, i.e. I have no hardwired internal wiring)

and you may be right BUT

The first thing Most ISP help lines will insist on is checking your connection at the master socket before they will commit any further checks .

 
The ES errors are High .Could be another indicator

The point is that you have a  pointer to some problem on your line as per your post

quote When things are bad I notice that picking up the phone (either for outgoing or incoming call) the SNR margin downstream can improve from around 9 to 12dB

When that is sorted then if your stats are still not right then it will be something else to ponder .
Regards Jeff
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mje_uk

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Re: Very erratic ADSL connection
« Reply #5 on: August 08, 2011, 07:26:13 PM »

Thanks for that Jeff

Regards

Mike
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waltergmw

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Re: Very erratic ADSL connection
« Reply #6 on: August 08, 2011, 07:32:07 PM »

Hi MJE,

It's worth noting that components can fail at any time so by using the test socket and hopefully a different filter you are changing all the active components as well as isolating everything else.

Some people just have to live with sporadic high errors. The picture below is one of the horror stories of about 7 km which I monitor regularly and you'll see the modem has fits of rage occasionally but it's a miracle the poor end users get anything at that distance.

Kind regards,
Walter

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mje_uk

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Re: Very erratic ADSL connection
« Reply #7 on: August 08, 2011, 08:20:26 PM »

Thanks Walter,

I'm interested to know how you know what "mode" you are set to ... or is that an ADSLmax parameter rather than ADSL2+ (which I believe is what I am on) ?
I'm also interested in knowing how you generate such a performance table .... looks as if you use something other than Routerstats, or have generated your own code.

Regards

Mike
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waltergmw

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Re: Very erratic ADSL connection
« Reply #8 on: August 08, 2011, 10:56:42 PM »

Hi Mike,

The picture is from a 2Wire 2700HGV AKA BT Business hub, but bought from Amazon or E-bay, which I prefer to install as I can monitor it easily from anywhere using LogMeIn on a lap top I leave on site so it doesn't disturb the user very much. If necessary I can do a soft remote re-boot - but only with the end user's permission and knowing the modem's password.

G.DMT is the now older ADSL 1 rate adaptive service mainly because there would be no benefit whatever with ADSL 2 on such a long line. This page will tell you of all the modulation types near the bottom.

Kind regards,
Walter

EDIT Thanks BK, Here's the ref

http://www.kitz.co.uk/adsl/linestats_explanation.htm
« Last Edit: August 09, 2011, 07:21:17 AM by waltergmw »
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burakkucat

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Re: Very erratic ADSL connection
« Reply #9 on: August 08, 2011, 11:42:05 PM »

Quote
This page will tell you of all the modulation types near the bottom.

Cough, ahem, Walter -- I think the reference you intended to supply has gone awol. :doh:
« Last Edit: August 08, 2011, 11:46:13 PM by burakkucat »
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