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Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

bin
Aspiring Pro
Posts: 167
Thanks: 56
Registered: 05-12-2014

Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

Well, after 5 engineers and some magic beans ('cos no-one actually did anything) I've actually had nearly 3 weeks of good behaviour from our connection.

Actually, not quite as last week it started dropping and on reconnection the speeds and SNRM were going off beam.

Oddly it dropped and reconnected on a couple of days at almost exactly the same time each day.

For a whole week we had  

Speed
<Time>29-6-17 05:31:16</Time>
    <Downstream>6656</Downstream>
    <Upstream>1255</Upstream>

SNRM
<Time>29-6-17 05:31:16</Time>
    <Downstream>6.1</Downstream>
    <Upstream>6.9</Upstream>

Nice and steady - just as it should be.

Now we're back to good old wandering connections

Speed
<Time>11-7-17 12:52:07</Time>
    <Downstream>5571</Downstream>
    <Upstream>675</Upstream>

SNRM
<Time>11-7-17 12:52:07</Time>
    <Downstream>9.1</Downstream>
    <Upstream>6.1</Upstream>

It has wandered further off than that.

Anyhoo - I thought I'd get in early on this occasion so that when it gets worse we'll have this info to hand.

4 REPLIES
Plusnet Help Team
Plusnet Help Team
Posts: 4,152
Thanks: 861
Fixes: 212
Registered: 21-04-2017

Re: Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

Sorry to hear the disconnections have started again.

 

The timestamps don't correspond to the drops we're seeing...

 

My tests aren't identifying the cause of that, but your sync speed has dropped to 5.5mbps which is below your estimates so I'd probably recommend getting a fault reported to us again at http://faults.plus.net and we'll arrange another engineer visit.

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
hitchhiker43
Aspiring Pro
Posts: 167
Thanks: 20
Fixes: 4
Registered: 06-07-2016

Re: Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

Very interesting your downstream snrm was increased by 3dB (from 6 to 9) that's a classic DLM intervention!

I would keep a careful eye on your errored seconds count as a high one is what makes the DLM intervene, if you are in a rural location like me and suffer REIN the DLM just makes the whole link unstable and if you ask Pnet nicely they might be persuaded to disable it, at least long enough to see if that improves the situation.

I can't see the Pnet reply as I write this but they don't seem to be seeing the same disconnections as you and that's really weird, maybe your modem clock is wrong ?

Tp-link W8960n on longgggggggg line!
bin
Aspiring Pro
Posts: 167
Thanks: 56
Registered: 05-12-2014

Re: Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

Thanks to both for the feedback.

Sorry, the timing of the dslstats extract was not related to the actual drops as they always seem to happen when I'm not looking or not logging! The figures were just to illustrate variations.

I am still convinced that all this is down to the constant background noise on the line. Line/voice engineers say there's nothing there when they test it, and yet it is there. The huge drop in speed over the short distance to the cab testifies that something is wrong but hey, what do I know.....

Anyway - yesterday pm while I was going through the fault logging wizard we had a short power blip - happened several times over the last couple of months - nearly missed the Grand Prix at Baku last time! So, when the power came back up I waited for modem to power up and speeds / SNRM back to normal.

I'll keep an eye on things and see if it starts to wander again in a week or two. I agree it does seem like DLM is behind all this, but whether anything can be done we'll have to wait and see.

Superuser
Superuser
Posts: 10,014
Thanks: 1,545
Fixes: 19
Registered: 22-08-2007

Re: Here we go again - speeds dropping - SNRM erratic - getting worse after each DSL drop

Let's be clear here, the DLM is not "behind this" it is simply responding to try to maintain connection stability.

If you think that there is line noise, that will be best illustrated by runnng constant monitoring and posting SNRM and synch speed plots here.  Point reports in isolation from the rest of the router stats tells us nothing.  Close after a resynch the SNRM is invariably going to be close to the Target SNRM of 6dB ... the only issue being that the synch speed might be variable, which is where plotting helps.