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At least one disconnection per day.

beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

At least one disconnection per day.

Hi,
I'm getting at least one disconnection per day. It seems as if interleaving is on and I'm getting a hell of a lot of errors.
Here are the stats from the modem:
(correct stats added to second post)
Any help/pointers would be greatly appreciated.
9 REPLIES
Community Veteran
Posts: 1,412
Thanks: 4
Registered: 29-01-2009

Re: At least one disconnection per day.

From those stats, we can see that DLM has intervened with the standard first choice: INP=3 and delay=8.
As a result, the modems have turned on interleaving (D>1) and FEC, where the overhead is (R=12, N=64) 12 bytes out of every 64, or just under 20% of the total bandwidth.
However, you've missed out most of the error statistics (use the "--stats" option instead of the "--show"); that limits what I can tell.
First is that your system has been available for 70 days (AS=6081961), but has only been unavailable for 21s (UAS=21); that is only long enough for a single synchronisation. Are you sure your disconnections are being caused by your modem?
Second, the error counters have accumulated 2741 ES's in that time, or 70 per day - which is pretty low. That ought to be low enough to allow DLM to reduce intervention. Conversely, the number of FECs that have accumulated is pretty high - comparing RScorr vs RSuncorr shows around 16% of all RS blocks need correction, which seems fairly high.
DLM normally monitors the ES rate when choosing to intervene or de-intervene, and yours doesn't seem high enough to warrant DLM's continued intervention. The FEC rate suggests that something is happening on the line (but is successfully handled by the FEC process), and it could well be that this really needs DLM intervention to be kept in place. It could well be that sometime (more than 70 days ago), DLM de-intervened but realised it was required again almost immediately.
Otherwise, there is nothing obvious to explain daily disconnections, or even to suggest that they exist.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

Re: At least one disconnection per day.

Here is the result of xdslcmd info --stats:
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 17093 Kbps, Downstream rate = 82696 Kbps
Path: 0, Upstream rate = 16064 Kbps, Downstream rate = 64291 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 8.4 6.5
Attn(dB): 0.0 0.0
Pwr(dBm): 13.5 7.5
VDSL2 framing
Path 0
B: 51 237
M: 1 1
T: 64 64
R: 12 16
S: 0.0257 0.4714
L: 19895 4311
D: 1259 1
I: 64 127
N: 64 254
Counters
Path 0
OHF: 3700541964 2225070
OHFErr: 22719 9960
RS: 2445784202 4275695
RSCorr: 162431550 442615
RSUnCorr: 1567877 0
Path 0
HEC: 377859 0
OCD: 7794 0
LCD: 7794 0
Total Cells: 492403456 0
Data Cells: 235825133 0
Drop Cells: 0
Bit Errors: 0 0
ES: 2755 9195
SES: 11 58
UAS: 21 21
AS: 6118838
Path 0
INP: 3.00 0.00
PER: 1.64 7.54
delay: 8.00 0.00
OR: 116.57 30.76
Bitswap: 1517356 230796
Total time = 1 days 19 hours 41 min 2 sec
FEC: 162431550 442615
CRC: 22719 9960
ES: 2755 9195
SES: 11 58
UAS: 21 21
LOS: 0 0
LOF: 0 0
Latest 15 minutes time = 11 min 2 sec
FEC: 1140 1
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 13887 21
CRC: 5 0
ES: 1 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Latest 1 day time = 19 hours 41 min 2 sec
FEC: 555001 669
CRC: 100 73
ES: 24 72
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 1803870 842
CRC: 502 135
ES: 64 121
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Since Link time = 49 days 17 hours 2 min 45 sec
FEC: 162431550 442615
CRC: 22719 9960
ES: 2755 9195
SES: 11 58
UAS: 0 0
LOS: 0 0
LOF: 0 0

I have been running DSLstats overnight and there seem to be lots errors but I don't know how to interpret the results. The disconnections occur at my router and may be the result of running dd-wrt on it, I will look into using an alternative.
beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

Re: At least one disconnection per day.

Here are some graphs from a screengrab from dslstats:
(as album)
Plusnet Help Team
Plusnet Help Team
Posts: 5,614
Thanks: 530
Fixes: 203
Registered: 01-01-2012

Re: At least one disconnection per day.

Hi there.
It looks like your line is dropping PPP rather then sync. Here's what we see below

It may be worth trying another router if you have one kicking around anywhere.
If this post resolved your issue please click the 'This fixed my problem' button
 Matthew Wheeler
 Plusnet Help Team
beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

Re: At least one disconnection per day.

Quote from: Matthew
Hi there.
It looks like your line is dropping PPP rather then sync. Here's what we see below
It may be worth trying another router if you have one kicking around anywhere.

What might explain the high number of errors?
Plusnet Help Team
Plusnet Help Team
Posts: 5,614
Thanks: 530
Fixes: 203
Registered: 01-01-2012

Re: At least one disconnection per day.

Good question.
There could be various things that could be causing the errors on the line ranging from interference to a actual fault on the line.
At the moment your line has interleaving applied on a low level so the errors are being corrected.
Aside from the drop-outs are the errors causing any issues?
If this post resolved your issue please click the 'This fixed my problem' button
 Matthew Wheeler
 Plusnet Help Team
beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

Re: At least one disconnection per day.

It seems to affect the speed of my connection and certainly affects the latency. I have rebooted the modem and am still experiencing high FEC rates, minimum of 1000/min and up to 20,000.
Community Veteran
Posts: 1,412
Thanks: 4
Registered: 29-01-2009

Re: At least one disconnection per day.

The increased stats confirm what I thought before: That
- The link seems to have stayed up all that time; 70 days by the AS counter, even though the last group of stats shows 49 days. The HG612 seems to stay stuck at the 49 day figure, even if uptime keeps going longer
- A very low downstream ES rate - 40 per day; this would normally be enough to get DLM to remove (or reduce) intervention
- A very high downstream FEC rate. Perhaps this is stopping DLM from de-intervening.
The thing to remember about the FEC count is that these are bit errors that have occurred during transmission down the copper line, but have been successfully corrected by the FEC protection. The RSuncorr counter, and indirectly the CRC counter, give an indication of how many times the FEC protection has failed. These counts are very low compared to the FEC error rate.
On the whole, this implies that the line encounters a *lot* of errors, but that the settings for FEC are enough to fix the vast majority. The latter means that DLM's choice of settings have tuned the fix, which in turn would imply the cause is REIN; very repetitive noise, not high impulse, and likely to be induced by electricity. Does your phone line runs close to some power lines, or in parallel with them? The obvious thing to do is to try turning things off, until the FEC counter stops moving so fast.
Also noticeable is that the upstream is encountering more noise then downstream. I'm not sure, but I think that might mean the noise source is more likely to be at your end of the line.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
beardedwonder
Dabbler
Posts: 17
Registered: 17-01-2015

Re: At least one disconnection per day.

There are no power lines near the phone line as far as I can tell. I will see if I can find a portable radio to locate any interference. Here are the stats since I rebooted the modem:
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 16701 Kbps, Downstream rate = 81612 Kbps
Path: 0, Upstream rate = 16713 Kbps, Downstream rate = 70612 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.0 6.0
Attn(dB): 0.0 0.0
Pwr(dBm): 13.5 7.4
VDSL2 framing
Path 0
B: 51 237
M: 1 1
T: 64 64
R: 12 16
S: 0.0234 0.4531
L: 21851 4485
D: 1381 1
I: 64 127
N: 64 254
Counters
Path 0
OHF: 57130369 292993
OHFErr: 227 150
RS: 1740304018 3374399
RSCorr: 5233123 919
RSUnCorr: 16599 0
Path 0
HEC: 3946 0
OCD: 101 0
LCD: 101 0
Total Cells: 3087992316 0
Data Cells: 805363486 0
Drop Cells: 0
Bit Errors: 0 0
ES: 45 143
SES: 0 0
UAS: 20 20
AS: 86010
Path 0
INP: 3.00 0.00
PER: 1.49 7.24
delay: 8.00 0.00
OR: 128.03 32.00
Bitswap: 29875 3206
Total time = 23 hours 53 min 52 sec
FEC: 5233123 919
CRC: 227 150
ES: 45 143
SES: 0 0
UAS: 20 20
LOS: 0 0
LOF: 0 0
Latest 15 minutes time = 8 min 52 sec
FEC: 172543 8
CRC: 0 5
ES: 0 5
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 256220 16
CRC: 8 6
ES: 2 6
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Latest 1 day time = 23 hours 53 min 52 sec
FEC: 5233123 919
CRC: 227 150
ES: 45 143
SES: 0 0
UAS: 20 20
LOS: 0 0
LOF: 0 0
Previous 1 day time = 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Since Link time = 23 hours 53 min 29 sec
FEC: 5233123 919
CRC: 227 150
ES: 45 143
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0