Continuous Resets of SmartHub2: Copper Broadband

[FrustratedCustomer68]

Beginning yesterday morning I experienced a recurrence of an occasional problem with my copper broadband, which is that the hub repeatedly resets. If I am lucky it eventually stabilises with an acceptable downstream speed just a little below what I typically get, but with an absurdly low upstream speed, usually of  64 kbit/s.

I am virtually certain that the cause is a noisy line, and indeed some noise is audible on the PSTN phone. Unfortunately however the problem is intermittent, albeit ongoing typically for several hours at a time, and bitter experience has proven that BT cannot cope with intermittent faults. I phoned the fault in yesterday and was offered an engineer visit, but I fear that the fault would not oblige by manifesting itself during an engineer visit, and therefore decided instead that fault should simply to be logged pending another call. And yesterday evening I managed to get a stable hub with an upstream speed of about 256 kbit/s, so the severity of whatever fault is causing the problem had presumably reduced. Sadly however the reduction was temporary and the problem returned sometime this morning.

Although the problem has occurred before it has not done so for many months, if not a year or more, and I suspect that something unusual is happening. I'm therefore posting to see if anyone can shed any light on what might be going on. In particular does a noisy line always indicate a problem with the line itself, or might electrical interference from someone using electrical equipment be responsible? Put another way, is this problem necessarily with BT's network?

Also, can cold weather, and possibly damp cause problems such as this? I've always considered that copper broadband is more likely to fail in hot weather because of any dry joints expanding, and even if it continues working its performance might be worse than usual because of increased electrical resistance. Perhaps this is too simplistic a view however.

I'm also puzzled as to why a problematic level of noise should affect the upstream speed more seriously than the downstream speed.

I'm happy to try and post hub stats if this might help, though I don't know whether I can access them when the problem is at its worse.

[imjolly]

have you tried using the test socket with a corded phone and checking for noise   dial 17070 option 2  should be silent.  any noise will affect your broadband so you need to report a noisy line and get engineer visit

[FrustratedCustomer68]

I haven't yet tried with the test socket, but I can do so, though I'd have to borrow a corded phone.

There is however audible noise on the line when using a cordless phone connected to the normal telephone socket and I find it hard to believe that it wouldn't be there on the test socket too.

Incidentally might it be worth trying a separate filter in the test socket? Although I think it an unlikely I suppose NTE5s can fail, though I suspect not intermittently.

[Keith_Beddoe]

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@FrustratedCustomer68 wrote:

Incidentally might it be worth trying a separate filter in the test socket? Although I think it an unlikely I suppose NTE5s can fail, though I suspect not intermittently.

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They do suffer from intermittent contact between the front and back sections, due to poor tension on the side clips.

With ADSL, there are a number of connections and relays in the broadband path, which can sometimes cause high resistance connections.

If you ring your phone line from a mobile, and leave it ringing for about 20 seconds before yo pickup the phone, that can help to clear any high resistance connections.

The other option is to dial 17070 and select option 1. Then replace the phone and let it ring for a while, before answering it.

[FrustratedCustomer68]

Thanks for the replies.

The situation improved markedly over the weekend. By midday on Saturday the problem had apparently resolved, though by this time I was connected to the NTE5 test socket using a filter.

I reassembled the NTE5 without incident, and all was well until Sunday evening when towards the end of a long PSTN phone call I heard crackling and saw that the hub had reset. After the phone call had ended I tried a simple power cycle but this didn't help, so then, as Keith suggested, I tried ringing the phone line from my mobile. This prompted another hub reset, but this time it came back with acceptable line speeds, though less than what I'd been getting for much of the day.

I therefore wonder if what Keith suggested is correct, and I suspect that his solution does in fact work. For the moment anyway I'm not going to ask for an engineer visit because plainly the fault is intermittent, and I think it's best that for now I keep everything under review. (I don't now if it's relevant now, but over a very long period, at various times, and when all seems to be well, using the PSTN has  apparently caused the hub to reset, and then it often comes back with a low upstream speed. This is usually solved by a power cycle, but it is annoying).

Ostensibly a noisy line is causing the current problem, as illustrated by these example stats, but I do wonder whether the cause of the noise is sticking relays introducing high resistance as Keith outlined.

Fri 08/01/21 2035

Data rate 64.0 Kbps / 4.2 Mbps (unacceptable u/s)
Maximum Data rate 184.0 Kbps / 4.3 Mbps
Noise margin 7.0/2.8
Line attenuation 31.5/53.5

Sat 09/01/21 1442

Data rate 448.0 Kbps / 4.6 Mbps (as good as it gets)
Maximum Data rate 1.1 Mbps / 4.8 Mbps
Noise margin 22.0/3.4
Line attenuation 31.5/53.5

Sun 10/01/21 1808

Data rate 448.0 Kbps / 4.6 Mbps (as good as it gets)
Maximum Data rate 1.2 Mbps / 4.7 Mbps
Noise margin 23.0/2.4
Line attenuation 31.5/53.5

Mon 11/01/21 1019

Data rate 448.0 Kbps / 4.2 Mbps (acceptable, but not the best d/s)
Maximum Data rate 1.2 Mbps / 4.4 Mbps
Noise margin 23.0/6.1
Line attenuation 31.5/53.0

Anyway, I'll post back when I've observed what happens for a while.

Again many thanks.

[FrustratedCustomer68]

Some recurrences of the problem, sadly, and I'm pretty sure always during, or shortly after, a phone call.

@Keith_Beddoe: you kindly suggested that "with ADSL, there are a number of connections and relays in the broadband path, which can sometimes cause high resistance connections", and I was wondering whether you could be more specific so that I could ask BT to check or replace relevant items of equipment. Hopefully this could be done without a home visit by an engineer.

Also, assuming that a high resistance contact is indeed the cause of the problems I'm having with my current ADSL service, would I be right in thinking that upgrading to fibre to the cabinet (VDSL) would probably fix them? I realise of course that it's impossible to be certain about this.

Thanks in anticipation.

[imjolly]

can you enter your phone number and post results remember to delete number   see what is available to you

https://www.broadbandchecker.btwholesale.com/#/ADSL

moving to vdsl will cut out your copper line from exchange to cab so will help reduce line problems

[Keith_Beddoe]

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@FrustratedCustomer68 wrote:

Some recurrences of the problem, sadly, and I'm pretty sure always during, or shortly after, a phone call.

@Keith_Beddoe: you kindly suggested that "with ADSL, there are a number of connections and relays in the broadband path, which can sometimes cause high resistance connections", and I was wondering whether you could be more specific so that I could ask BT to check or replace relevant items of equipment. Hopefully this could be done without a home visit by an engineer.

Also, assuming that a high resistance contact is indeed the cause of the problems I'm having with my current ADSL service, would I be right in thinking that upgrading to fibre to the cabinet (VDSL) would probably fix them? I realise of course that it's impossible to be certain about this.

Thanks in anticipation.

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There are relays in the ADSL equipment to bypass the PSTN filters during a line test, and  in the TAMS (Test and Monitoring System), plus a large number of interconnections on the exchange frame which can cause high resistance connections. Unsoldered or poorly soldered joints are another cause.

BT would not replace any equipment unless it was causing a complete disconnection. In some exchanges with older equipment, ADSL is being phased out, and customers are being offered a free "upgrade" to VDSL.

You can also get high resistance connections on the external network which would still be there on a VDSL connection. But they would only be in the cabinet and other distribution points.

An incoming phone call can temporarily clear most of these faults, so its not easy to locate the actual cause, even after a visual inspection.

Whether a VDSL connection would be any better, is difficult to tell, but you would have to be certain you would actually get a faster connection on VDSL, as that depends on the distance to the VDSL enabled cabinet.

On an ADSL connection, the Home hub 4 is more suitable, not the Smart Hub 2.

I noticed you mentioned about upstream being more affected than downstream. That is because the much lower frequency allocation for the upstream path, makes is more susceptible to noise, and you can normally hear that on the phone.

[FrustratedCustomer68]

Thanks @imjolly . I've attached a screenshot of the BT Wholesale Broadband Checker output for my number, having scrolled to avoid displaying the number itself. I'm afraid that there doesn't appear to be a means of exporting the data to a .csv file or spreadsheet. It does appear that VDSL is available.

[Keith_Beddoe]

VDSL would be a worthwhile upgrade in your case. Also Openreach would be re-making all the cabinet connections to include the fibre cabinet, and that would eliminate any issue there.