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Aspiring Contributor
Message 1 of 43

Constant disconnection, triggered by uploads

We've been having constant issues since joining back with BT around a year ago. The download speed is actually pretty fast when connected, but the problem is that it's constantly coming to a hault on all devices multiple times a day and has become unusable in the last few months. We've tried everything, including switching to a new router that can handle more devices, but we still have issues. I've noticed that it seems to be linked to uploading, not even particularly large files, but it causes the whole internet to dropout, showing limited internet on our devices, but still appearing as connected on the router.

As I'm a web developer it's making it impossible to work, I've had to use mobile data for testing web sites and apps and they're not even very intensive sites. I can consistently bring the internet down for everyone, just by trying to access an app and it's because it requires sending data over the internet, i.e uploading. I don't expect the upload speed to be super fast here, but I don't expect it to bring down the whole connection.

We've just today had an engineer around who tweaked our download SNR as the line was too fast but it's not resolved the issue. I was able to show him how it just haults when I try to access my web application (just a simple Shopify admin app). I tried turning on QoS on the TP Link router we had, it made it slightly more stable if I limited uploads to stupidly low (200Kbps) but didn't fix it completely. It does this on both a wired and wireless connection. 

Doing a speed test shows that our upload bufferbloat is huge (over 3 seconds) and marked as a fail, but our download is pretty stable:

We've switched back to the BT Smart Hub just so that testing can be done on your end. Here are the current stats:

Firmware version:v0.09.06.05093-BT
Firmware updated:unknown
Board version:01
DSL uptime:0 days,01 Hours08 Mins52 Secs
Data rate:1.013 Mbps / 17.266 Mbps
Maximum data rate:1.010 Mbps / 17.260 Mbps
Noise margin:6.6 / 6.1
Line attenuation:11.0 / 23.1
Signal attenuation:10.6 / 21.3
Latency type:Interleaved
Data sent / received:43.3 MB / 153.9 MB
BT Wi-fi:Activated
2.4 GHz wireless network name:BTHub6-N6TR
2.4 GHz wireless channel:Automatic (Smart Wireless)
5 GHz wireless network name:BTHub6-N6TR
5 GHz wireless channel:Automatic (Smart Wireless)
Wireless security:WPA2
Wireless mode:Mode 1
MAC address:BC:30Smiley Very Happy9:0E:B5:BA
Software variant:-
Boot loader:0.1.6-BT (Fri Sep 9 10:05:09 2016)
Please help. Do you know what would cause this issue? I am lost as to what to try next. It's interesting too that the issues seemed to start as they were connecting fibre into the village beside us which uses the same exchange. They're currently fitting fibre into our village but we have no idea when this will be available to us.
Distinguished Sage
Distinguished Sage
Message 2 of 43

Re: Constant disconnection, triggered by uploads

This is just a customer to customer forum.

One thing that may cause this, would be a faulty or misconfigured port on the exchange MSAN which is not communicating properly with the 21cn core network.

You should not actually get a disconnect if the flow control is working properly. Three seconds buffering is excessive, which would seem to me to be an internal connectivity issue within the 21cn equipment

The only way to prove this would be a lift and shift to a different port in the exchange.

I have asked a moderator to provide assistance, they will post an invite on this thread.
They are the only BT employees on this forum, and are based in the UK.

Aspiring Contributor
Message 3 of 43

Re: Constant disconnection, triggered by uploads

Thank you so much for such a quick response! We've been going around in circles on the phone. I'll wait for the response from the moderator.

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Message 4 of 43

Re: Constant disconnection, triggered by uploads

Hi @clbone welcome to the forum and sorry to hear that you are getting disconnected when uploading files.

I've sent you a Private message explaining how you can contact the forum moderation team. check here


Community ModeratorJohnC
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Aspiring Contributor
Message 5 of 43

Re: Constant disconnection, triggered by uploads

Thank you, I've just sent a PM Smiley Happy
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Distinguished Sage
Distinguished Sage
Message 6 of 43

Re: Constant disconnection, triggered by uploads

I would be interested to hear the outcome of this. I also thought you may still be connected to the old exchange DSLAMs, although many of those were being ofloaded when I retired nine years ago. I do remember similar issues with those.

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Aspiring Contributor
Message 7 of 43

Re: Constant disconnection, triggered by uploads

Thank you, I'll keep you updated. We are in a very rural area so I'd not be surprised if we had old equipment! although it didn't used to cause issues.

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Distinguished Sage
Distinguished Sage
Message 8 of 43

Re: Constant disconnection, triggered by uploads

@clbone wrote:

Thank you, I'll keep you updated. We are in a very rural area so I'd not be surprised if we had old equipment! although it didn't used to cause issues.

Then you could well be on a DSLAM. The MSANs are only fitted where the new 21cn equipment has been installed. There used to be plenty of DSLAMS, and they did get faulty ports on a card.

It caused too much disruption to change a card (lots of users), so it was a case of moving a circuit to a different port.



Aspiring Contributor
Message 9 of 43

Re: Constant disconnection, triggered by uploads

So we just had an engineer over. He did lots of tests and after speaking on the phone to a colleague they agreed that a lift and shift was the next course of action, as the uploads were stalling and the ping was rediculously high. Bad news is that this lift and shift has not solved the issue and he's said that it'll be something that BT are doing their end.

We've ruled everything else out, nothing is wrong with the hardware so something is causing our ping to be huge and making our internet pretty much unusable.



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Distinguished Sage
Distinguished Sage
Message 10 of 43

Re: Constant disconnection, triggered by uploads

Thanks for updating the thread. I cannot suggest anything else. Its going to need to be escalated by the moderator, perhaps BT Wholesale can look at the network path, I am not sure who deals with this sort of problem any more.

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