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Frequent Disconnects and Speed Drop

sweeep1963
Grafter
Posts: 63
Thanks: 2
Registered: ‎25-08-2019

Re: Frequent Disconnects and Speed Drop

Going through my old posts I can see that back in 2019 when we were getting speeds above 50, the SNR was down at 3dB, compared to 6.3 now. Any way to get this down again?

jab1
Legend
Posts: 18,961
Thanks: 6,216
Fixes: 286
Registered: ‎24-02-2012

Re: Frequent Disconnects and Speed Drop

The SNR is usually controlled by the DLM equipment in the cab, and will be higher due to whatever is causing your connection speed to be so low. You could ask PN to reset it, but if the cause is still there, DLM will raise it.

John
sweeep1963
Grafter
Posts: 63
Thanks: 2
Registered: ‎25-08-2019

Re: Frequent Disconnects and Speed Drop

I've now used telnet to check the stats and it shows 555 CRC errors, as well as some error seconds in the last 1 day

jab1
Legend
Posts: 18,961
Thanks: 6,216
Fixes: 286
Registered: ‎24-02-2012

Re: Frequent Disconnects and Speed Drop

I'm now getting out of my comfort zone - not a networking expert, and never had any call to start worrying about error counts, so not done much research.

Maybe @MisterW  or @Dan_the_Van may like to take over?

Out of curiosity, are you actually reading and understanding my replies?Huh

John
MisterW
Superuser
Superuser
Posts: 16,154
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Registered: ‎30-07-2007

Re: Frequent Disconnects and Speed Drop

Going through my old posts I can see that back in 2019 when we were getting speeds above 50, the SNR was down at 3dB, compared to 6.3 now. Any way to get this down again?

Normally the DLM will have a target noise margin of 6db, if the error count is low then the DLm will reduce the target to 3db thus allowing a faster synch speed. Sounds like, in the past your line was performing well and the target was reduced. Your line has been reset recently and the target is back to 6db. Your line has likely deteriorated in the mean time, thus giving more errors and so the DLM will not reduce the target.

've now used telnet to check the stats and it shows 555 CRC errors, as well as some error seconds in the last 1 day

That's not a stupidly high error count, but is going to be sufficient for the DLM not to reduce the target SNR

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

greygit
Rising Star
Posts: 196
Thanks: 20
Fixes: 1
Registered: ‎13-11-2021

Re: Frequent Disconnects and Speed Drop

Pre-amble.

The hub2 doesn't report error counts. My old modem did.

 

Error counts.

I'd ask over what period of time have those errors occured (and is there the ability to reset the error counters without rebooting the modem, because rebooting the modem entails other potential downsides). Past experience of my old modem says to me that those error counts are not that excessive (for a consumer line). I've seen worse. I've seen better (on a commercial fibre link) where that level of detected errors was causing a problem.

 

I could go on with an hypothesis, but I'd get told off.

Gandalf
Community Gaffer
Community Gaffer
Posts: 26,634
Thanks: 10,212
Fixes: 1,606
Registered: ‎21-04-2017

Re: Frequent Disconnects and Speed Drop

@sweep1963, how are things after the engineer visit last Friday? 

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
sweeep1963
Grafter
Posts: 63
Thanks: 2
Registered: ‎25-08-2019

Re: Frequent Disconnects and Speed Drop

The engineer couldn't find anything wrong so requested a new router to be sent out. I'm not sure if that was passed on as I haven't received any confirmation? Otherwise since then the modem has resynced several times and sync speed has climbed up each time and is now at 48. However we did experience a disconnect yesterday requiring a restart, so hoping to try out that router when it arrives to see if it makes any difference!