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Samorai
Beginner
3,993 Views
Message 1 of 9

Homehub 2 keeps resetting broadband and phone line

I'm hoping someone here might be able to help with this problem that started just before Christmas and keeps coming back intermittently.

 

At certain points, the broadband light will go off, shortly followed by the phone line which both then reset themselves but usually repeat the process in a few seconds (sometimes in stays connected for an hour before resetting again). I phoned BT's technical assistance line and didn't have much luck explaining that it didn't appear to be a 'replicable' error when using the PC but the advisor did tell me about changing the wireless encryption from WEP to WPA which did seem to solve the problem for a day or so.

 

I've read the forums and tried the following solutions:

 

1) New ADSL filter (I didn't replace the cable)

2) The router isn't near any power sockets and is at least 3 feet away from the TV/Xbox and their power supplies.

3) The only device connected wirelessly (via Channel 11) is the laptop

4) I've done the Quiet Line test from the wireless handset attached to the hub and there is a very faint hissing.

 

 

I've had the Homehub since I re-joined BT about 3 years ago. Below is the ADSL report from the Homehub's settings:

 

Line stateConnected
Connection time0 days, 0:16:58
Downstream23,669 Kbps
Upstream1,171 Kbps

 

ADSL settings
VPI/VCI0/38
TypePPPoA
ModulationITU-T G.992.5
Latency typeInterleaved
Noise margin (Down/Up)4.1 dB / 6.4 dB
Line attenuation (Down/Up)17.5 dB / 8.7 dB
Output power (Down/Up)0.0 dBm / 11.4 dBm
Loss of Framing (Local)13
Loss of Signal (Local)1
Loss of Power (Local)0
FEC Errors (Down/Up)0 / 4294967264
CRC Errors (Down/Up)49 / N/A
HEC Errors (Down/Up)N/A / 0
Error Seconds (Local)884

 

I'd appreciate any advice as I seem to be not having much luck.

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8 REPLIES 8
NilSatisOptimum
Recognised Expert
3,979 Views
Message 2 of 9

Re: Homehub 2 keeps resetting broadband and phone line

Hi,

 

Are you able to connect to your test socket and monitor-

 

mastersocket2.jpg

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Distinguished Sage
Distinguished Sage
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Message 3 of 9

Re: Homehub 2 keeps resetting broadband and phone line

Does this happen when its gets dark outside? What time did you measure those ASDL statistics?

 

Its quite possible that its due to the fact that BT have been lowering the minimum downstream noise margin, and increasing the depth of interleaving, to try to improve connection speeds.

 

As your downstream margin is 4.1db, when that measurement was taken, that is probably very close to the limit that your line will support, without re-syncing, as you have a very good connection speed.

 

As it gets dark, this margin is likely to reduce, and your line will become unstable. This is doe to a general increase in radio interference when it gets dark. This is usually worse on lines that run overhead, on part of their route.

 

When this starts to happen, I would suggest that you unplug the ADSL input to the hub, about five times, leaving the plug out for about 10 seconds each time, then plugging it back in, and waiting until the broadband light comes back on, before repeating the process. You can disconnect it at the microfilter if its easier.

Do not restart the hub, as this does not do the same thing, and may make matters worse.

 

This will manually force a re-sync and should persuade the exchange and the hub, to use a better selection of tones, and/or,

decrease the connection speed slightly.

This should result in a slightly larger downstream noise margin, but a much more stable line.

 

Eventually the DLM will decide on an optimum connection speed, which is stable, and has a good S/N safety margin.

 

Samorai
Beginner
3,955 Views
Message 4 of 9

Re: Homehub 2 keeps resetting broadband and phone line

NilSatisOptimum: The primary phone socket in the flat appears to be one of the old style, square ones - I removed the cover (very gingerly, it turns out whoever fitted it was a bit stingy with wire and it didnt open very far) and there doesn't appear to be anything like the connector you pictured.

 

Keith: I copied those results about half an hour before I posted the initial message, so around 11pm last night. The problem does seem to happen around 4-5pm or later, as you say, when it's dark outside - I don't know if it happens during the day as that's when I'm at work but I have had two instances where it started around lunchtime on the weekends.

 

As for the lines overhead bit, I can't comment on that, I live in the centre of Bath where there aren't any overhead lines (all underground to preserve the Georgian architecture) but according to locals, the lines can be notoriously tempremental if somebody knocks a contact in the underground lines, I don't know if that counts.

 

I'll wait until it happens again and follow your 5 x plug/unplug guide and see what hppens. I'm assuming I just do this every time it happens - do you have a rough idea how many times this'll take before it holds, just so I've got a rough idea when I can report back?

 

It's a shame this has started happening, since I moved from the outskirts, the speed tripled, BT reduced my bill by £10 a month - oh well!

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Distinguished Sage
Distinguished Sage
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Message 5 of 9

Re: Homehub 2 keeps resetting broadband and phone line

Re-syncing a couple of times in a short period, should result in a slightly higher noise margin, provided there are enough available "good" tones to use. Otherwise the speed might have reduce slightly to achieve the same effect.

 

If you like, you can check the S/N margin after each re-sync, and if you find that its around 6db in the evening, that should give you a bit more leeway, and you can leave it like that.

 

It will probably creep up to 8db or so during the day, when interference levels are lower.

 

You have to understand that ADSL uses radio frequencies from 30khz to 2.2mhz (ADSL2+), so the potential for interference is great.

In the evening, medium wave broadcast stations get stronger, and other sources of interference like TVs, light dimmers, thermostats etc, all degrade the ADSL signal.

 

Any slight line inbalance on your telephone line can also make the problem worse.

 

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Samorai
Beginner
3,870 Views
Message 6 of 9

Re: Homehub 2 keeps resetting broadband and phone line

You're solution seemed to sort things out for a week or so, Keith, alas it seems to have started it doing it again. I might be missing something - is the 5x unplugging something you have to do once a week continuosly or should it eventually fix things for good? I've just taken the stats again: Line state Connected Connection time 0 days, 0:03:51 Downstream 22,933 Kbps Upstream 1,159 Kbps ADSL settings VPI/VCI 0/38 Type PPPoA Modulation ITU-T G.992.5 Latency type Interleaved Noise margin (Down/Up) 4.0 dB / 6.7 dB Line attenuation (Down/Up) 17.5 dB / 8.7 dB Output power (Down/Up) 0.0 dBm / 11.5 dBm Loss of Framing (Local) 0 Loss of Signal (Local) 0 Loss of Power (Local) 0 FEC Errors (Down/Up) 0 / 4294967264 CRC Errors (Down/Up) 553 / N/A HEC Errors (Down/Up) N/A / 0 Error Seconds (Local) 1 Is there anything else I can or would it best to get use the 'report a line fault' on the BT website? Any help would be greatly appreciated!
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Distinguished Sage
Distinguished Sage
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Message 7 of 9

Re: Homehub 2 keeps resetting broadband and phone line


@Samorai wrote:
You're solution seemed to sort things out for a week or so, Keith, alas it seems to have started it doing it again.
Reformatted to make it readable
Line state Connected
Connection time 0 days, 0:03:51
Downstream 22,933 Kbps Upstream 1,159 Kbps
ADSL settings VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 4.0 dB / 6.7 dB
Line attenuation (Down/Up) 17.5 dB / 8.7 dB
Output power (Down/Up) 0.0 dBm / 11.5 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local)0
FEC Errors (Down/Up) 0 / 4294967264
CRC Errors (Down/Up) 553 / N/A
HEC Errors (Down/Up) N/A / 0

There is something odd going on. Your latency is set to interleaved, but there are no downstream FEC errors showing, which seems wrong to me, especially as there have been 533 CRC errors in 3 minutes.

 

Your downstream noise margin is 4.0 db which is about right.

 

There must be a certain amount of noise causing the CRC errors, but if Forward Error Correction (FEC) was working properly, these errors should have been corrected.

 

You could try disconnecting the line again as I suggested last time, but I would suspect that the exchange DLM would eventually revert to the same profile.

 

Reporting it to the BT help line is probably going to be a waste of time.

 

You really need someone who can read what has been written here, and follow the fault to conclusion.

 

The default noise margin needs to be raised so that it never drops below 6db. Also the reason why error correction is not happening needs to be looked at.

 

Your best option would be to ask one of the BT Care Forum Moderators to investigate on your behalf.

They have the tools to monitor broadband performance, and have contacts within BT Wholesale.

 

You will need to refer them to this thread.

 

The contact form is here http://bt.custhelp.com/app/contact_email/c/4951

 

They may take a couple of days to reply, depending on how busy they are, but they have a very good reputation for getting things fixed.

They should also be able to understand my comments about the DLM profile.

 

I am sorry that I cannot suggest anything else at the moment, as it needs BT intervention.

 

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Samorai
Beginner
3,848 Views
Message 8 of 9

Re: Homehub 2 keeps resetting broadband and phone line

Whoops, sorry about that! Thanks for reformatting that. I've done as you suggest and submitted the thread to one of the moderators. Thanks again for your help!
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Distinguished Sage
3,847 Views
Message 9 of 9

Re: Homehub 2 keeps resetting broadband and phone line

I agree with Keith's comments get the mods involved
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