Can anyone please explain to me....

[Zirynx]

... why this happens!



This is my mum's IDnet 'Max' connection and every now and again (I'd say sometimes it can be once every two or three weeks, other times it can be two or three times a week!) this is what happens. The line suffers fairly sudden, intense packet loss, and the router (a Netgear DG834G) starts reporting zero (or near zero) SNR (so it's amazing it hangs onto any connection at all, and frequently it doesn't) and this is the ping result.

My sister and myself each have different (non IDnet) 'Max' connections and also use the same model of router at the same firmware revision (as the family tech, it makes my life easier!) but neither of us experience this kind of packet loss. Indeed our routers typically run for thousands of hours without dropped or re-initiated connections.

In the above example, I remotely logged in to my mum's router this morning and did a soft reboot (can be seen clearly), and immediately upon restart, it registered a SNR of 15dB and no packet loss. This is very frustrating as it suggests there is nothing physically wrong, but that something 'soft' is going belly up.

In the past, I've even swapped all our routers (filters, PSUs, cables etc...) around and the 'problem' remains with my mum's connection, and not the router. Some time ago, I spoke to IDnet at length about this, but there has never been a conclusion, and we ended up going around in circles so I've just let it go for a while, and rebooted as necessary; but it's all now rather tiresome and, it seems to me, unnecessary.

BT have visited the house (at IDnet's request, which was all very expedient and well handled) but they found nothing wrong. Regardless, they kindly replaced the master socket with a new-fangled NTE5, FOC. This made no difference.

Ironically, the intention was that after my mum was settled into IDnet (her previous ISP was not available at the exchange when she moved house), my sister and I would follow (again, simply to keep us all in line from a tech support perspective), but that has never happened simply because her IDnet connection is not as reliable as either of ours, and we are talking about often maligned providers here!

Is anyone able to shed any light on this, or justify why it should be the 'norm'?

Thanks.

[Rik]

The 15db noise margin suggests that her line is regularly unstable and that the BT DLM software has, in response, pushed up her target noise margin in an attempt to stabilise. At the same time, interleaving will have been turned on, so ping times will have increased.

This is invariably caused by noise or a line fault and, given that BT have been out and not raised a charge, it suggests that the problem is external to your mother's property. Beyond disconnecting the ringwire at all sockets if there are hard-wired extensions, it seems unlikely that you can do more. It would, however, be worth letting IDNet know the problem is ongoing, they may be able to persuade BT to try something else.

[Zirynx]

Thanks Rik.

IIRC, IDnet have, in the past initiated an increase in the target SNR; I think they requested it, in an effort to achieve greater stability which, in my mum's case is far more important that out and out speed. On a 'non fault' day, the ping time is usually up in the 60 to 70 ms range (I get about 20-25 ms with my ISP and my sister gets about 10-15 with hers!!!!) but it's the packet loss, and ultimately, the effective complete loss of connection that is the main problem.

I suppose I should speak to IDnet support again but I'm really not sure where we can go that we haven't been before! Posting here was a 'call for help' and an indication of my frustration with it all, especially as I'm remote from the actual problem.

I will call support.

[Rik]

I know what must be happening, but no-one here can do anything to fix the problem. IDNet can try to get BT to fix it, but ultimately BT can simply condemn the line as being unsuitable for ADSL.

A different router might help, what's the downstream attenuation and sync speed?

[Zirynx]

This screenshot taken a few moments ago, after a soft reboot a few hours ago.



I can't claim to be an expert on these stats but, when it's 'good' it doesn't look too bad to me. It's really the sudden change (evident in the graph in the original post) and subsequent ongoing packet loss that is the main problem.

[Rik]

For a 43db attenuation, I'd expect a much higher sync, but you are losing 1500-2100k because of the increased target margin. The fact that the noise is still enough to cause losses of sync suggests it's pretty hefty, does the phone line route near an industrial estate or railway line, for example?

Using a 2700 router might help, it stabilised an 11db 'swing' in my NM to just 2db, but there's no guarantee.

If the cable route is not suspicious, ie near potential sources of noise, then you could try reporting intermittent crosstalk, being able to hear other people's conversations, as a voice fault. Normally, BT will then swap the pair, which would eliminate the cable - but if the issue is external noise it won't help much.

Have you tried running Routerstats to graph the Rx NM?

[Steve]

Sorry for being thick but what does the graph show,is it ping times?

[Zirynx]

It shows ping 'result' which includes time.

In very broad terms...

Yellow means successful ping, good time.
Green means successful ping, poor time.
Blue means successful ping, downright awful time!
Red means unsuccessful ping, ie: full packet loss!!

Ping time is on the vertical axis, whilst TOD is on the horizontal axis.

You can see that 'normal' ping at this location is around 60ms.

[Steve]

Thanks.

[Zirynx]

For a 43db attenuation, I'd expect a much higher sync, but you are losing 1500-2100k because of the increased target margin.

Agreed. I was informed previously by IDNet that raising the target SNR would have this result, but I indicated that this was an acceptable compromise, in the interest of stability.

The fact that the noise is still enough to cause losses of sync suggests it's pretty hefty, does the phone line route near an industrial estate or railway line, for example?

I'm not aware of any such obvious locations on the likely cable route.

Using a 2700 router might help, it stabilised an 11db 'swing' in my NM to just 2db, but there's no guarantee.

If the cable route is not suspicious, ie near potential sources of noise, then you could try reporting intermittent crosstalk, being able to hear other people's conversations, as a voice fault. Normally, BT will then swap the pair, which would eliminate the cable - but if the issue is external noise it won't help much.

There is nothing to indicate that there is a 'voice' noise problem.

Have you tried running Routerstats to graph the Rx NM?

No, but that's because it's only available for Windows, and we're a 'Mac' family

I have emailed support with a link to this topic. Hopefully they will pick it up, on or off board.

[Rik]

There is nothing to indicate that there is a 'voice' noise problem.

No, but if the cable is the issue it's a good way of getting it changed quickly.

No, but that's because it's only available for Windows, and we're a 'Mac' family

Ah!

I have emailed support with a link to this topic. Hopefully they will pick it up, on or off board.

Simon and Andrew have both been reading this thread. Unfortunately, they won't be able to identify you from it as you're not on an IDNet IP address.

[Zirynx]

Simon and Andrew have both been reading this thread. Unfortunately, they won't be able to identify you from it as you're not on an IDNet IP address.

Customer details already supplied to IDNet in the support email, although I forgot to paste the link to this topic

Since then, I have been contacted by (and responded to) Simon, directly.

[Rik]

He must have recognised you some other way - it is a very personal service with IDNet. 

[Zirynx]

He must have recognised you some other way - it is a very personal service with IDNet. 

He did say that he recalled out previous conversations (and that was quite a while ago!!) but also, there aren't too many 'connection issues' threads today... thankfully for IDNet

I've said it plenty before when I've posted here, that IDNet's support really is prompt, polite and attentive; it's just that (and I mean this in the nicest possible way) I'd rather not speak to them at all

[Rik]

Most of us never need to.

[Inactive]

Never had cause to speak with IDNet in almost 2 years.. 

[Zirynx]

A question for you Rik...

Do you know whether Routerstats records the actual SNR of the line, or the SNR value as interpreted and currently displayed by the router?

Thanks.

[Sebby]

It's the SNRM as reported by the router, so it could be inaccurate, but I'd say it's probably right.

[Zirynx]

Thanks.

I was curious because a short while ago I logged into the router to find it was indicating a SNR of 0dB yet again, and I just wondered whether the router might be displaying an inaccurate value, and therefore Routerstats wouldn't achieve very much if it was simply graphing reported inaccurate data.

However, I just noticed that the connection has now dropped completely (and hasn't restarted, and probably won't for ages ) so, with hindsight, I guess the router was actually 'correct' and the connection was about to go belly up at any moment, which it now has. 

[Sebby]

[Dopamine]

Thanks.


However, I just noticed that the connection has now dropped completely (and hasn't restarted, and probably won't for ages ) so, with hindsight, I guess the router was actually 'correct' and the connection was about to go belly up at any moment, which it now has. 

I've been trying for the last year to help a friend with similar problems. Monitoring her line remotely using Routerstats, her Netgear DG834PN Router will show a stable SNR value of 15db for several days, then suddenly there are huge hits of noise, and like you, the connection drops and will often not reconnect again, sometimes for hours. Other times the sync, normally around 2400, will drop to 160.

BT have been out numerous times, fiddled about, lifted and shifted, but still the same problem. It's now at the point that pestering BT any further risks having the line deemed unsuitable for ADSL, so we're having to accept it as it is, which, frankly, is terrible service from BT.

I wasn't present when the last engineer visited, but he apparently mentioned that BT have a small number of expert "noise" investigators (have read something similar on Kitz's forum) and that if you push really hard, and are lucky, you may get one to visit. By all accounts it's not unknown for a faulty Sky box or other electrical appliance somewhere in a neighbourhood to knock out, or make very unstable, a whole street's worth of ADSL connections.

I don't know any more specifics about these noise engineers, but it may be an avenue worth investigating before BT give up on your line and you risk losing ADSL completely.

[Lance]

I think the team is the sfi, special fault investigation, team. I might just be making that up though!

[Simon]

When are BT going to acknowledge that ADSL is part of the service they provide, not just a favour to customers lucky enough to be on a decent line?  Surely, by now, they should be providing adequate support for broadband connections?

[Lance]

Probably when ofcom relax the USOs BT are bound to...

[Sebby]

When are BT going to acknowledge that ADSL is part of the service they provide, not just a favour to customers lucky enough to be on a decent line?  Surely, by now, they should be providing adequate support for broadband connections?

I surprised they even admit that voice is something they have to offer tbh, Simon. Their infrastructure is just so old and needs a complete overhaul for things to change.