Help me diagnose my VDSL issue
Discussion
Hi all 
Long post sorry, trying to be thorough!
My VDSL, which was stable for a couple of years has started playing up since early December. Going down at least once every couple of days, sometimes 2 to 3 times. It generally resyncs a couple of minutes later. DLM has been going mad, changing interleaving level, g-inp and resulting connection speeds all over the place.
I use a small ISP (who are very helpful) but ultimately I'm at the mercy of BT. I had an engineer out a couple of weeks ago and they did a line test (all 'ok', which was expected as most of the time it is) however they changed the master socket (and faceplate) to the latest. I already had a decent faceplate so didn't expect any improvement, and didn't get one.
I've tried:
I'm told my "error" is not bad enough to warrant a callout without charge. I would like an engineer to check both the pole outside and the cabinet for any issues - perhaps corrosion or some such. Surely this is an acceptable request?
Here are some stats, from DSLstats, which I have monitoring the line 24/7. I just had another internet drop while composing this!
If you got this far, the only indication of the latest drop is FEC errors going insane and G.INP plotting it.
ES stays low.
SNRM stays level.
A long time ago I had an issue (on ADSL) caused by a faulty PSU in some LED lights. This was clearly visible in the SNRM decreasing over a 30 minute period as the PSU got hot. I don't see anything like this here.
I'm convinced it must be a line issue, but do you agree? How do I persuade my ISP/BT to check further without charging me!
If you got this far, please please any suggestions on how to get this sorted!
Long post sorry, trying to be thorough!
My VDSL, which was stable for a couple of years has started playing up since early December. Going down at least once every couple of days, sometimes 2 to 3 times. It generally resyncs a couple of minutes later. DLM has been going mad, changing interleaving level, g-inp and resulting connection speeds all over the place.
I use a small ISP (who are very helpful) but ultimately I'm at the mercy of BT. I had an engineer out a couple of weeks ago and they did a line test (all 'ok', which was expected as most of the time it is) however they changed the master socket (and faceplate) to the latest. I already had a decent faceplate so didn't expect any improvement, and didn't get one.
I've tried:
- test socket (there are no extensions anyway)
- changing all cables, both modem and ethernet
- trying a different modem (Draytek Vigor 130)
- different filters
- ferrite core on all power cables
- moving DECT phone to different room. Trying a spare DECT phone base.
- unplugged Powerline I was using to extend WiFi
- swapped switch
- Different configuration of modem (from bridged mode with UniFI USG to Router/Modem with double-NAT to help isolate issue)
- quiet line test - checks out ok.
I'm told my "error" is not bad enough to warrant a callout without charge. I would like an engineer to check both the pole outside and the cabinet for any issues - perhaps corrosion or some such. Surely this is an acceptable request?
Here are some stats, from DSLstats, which I have monitoring the line 24/7. I just had another internet drop while composing this!
Stats summary
Stats recorded 18 Jan 2020 11:33:05
DSLAM type / SW version: BDCM:0xc01c (192.28) / v0xc01c
Modem/router firmware: AnnexA version - A2pv6F039g1.d24m
DSL mode: VDSL2 Profile 17a
Status: Showtime
Uptime: 0 hour 8 min 47 sec
Resyncs: 1 (since 18 Jan 2020 09:22:31)
Downstream Upstream
Line attenuation (dB): 27.3 0.0
Signal attenuation (dB): Not monitored
Connection speed (kbps): 28834 2859
SNR margin (dB): 6.6 6.3
Power (dBm): 10.8 5.9
Interleave depth: 8 1
INP: 43.00 0
G.INP: Enabled Not enabled
Vectoring status: 1 (VECT_FULL)
RSCorr/RS (%): 0.0025 0.0000
RSUnCorr/RS (%): 0.0000 0.0000
ES/hour: 15.6 1.89
Connection stats
adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 1
Last initialization procedure status: 0
Max: Upstream rate = 2859 Kbps, Downstream rate = 29534 Kbps
Bearer: 0, Upstream rate = 2859 Kbps, Downstream rate = 28834 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.6 6.3
Attn(dB): 27.3 0.0
Pwr(dBm): 10.8 5.9
VDSL2 framing
Bearer 0
MSGc: -6 26
B: 243 79
M: 1 1
T: 0 41
R: 10 6
S: 0.2695 0.8832
L: 7541 779
D: 8 1
I: 254 86
N: 254 86
Q: 8 0
V: 0 0
RxQueue: 21 0
TxQueue: 7 0
G.INP Framing: 18 0
G.INP lookback: 7 0
RRC bits: 0 24
Bearer 1
MSGc: 90 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 10.6667 0.0000
L: 24 0
D: 1 0
I: 32 0
N: 32 0
Q: 0 0
V: 0 0
RxQueue: 0 0
TxQueue: 0 0
G.INP Framing: 0 0
G.INP lookback: 0 0
RRC bits: 0 0
Counters
Bearer 0
OHF: 0 67965
OHFErr: 0 0
RS: 9093840 2785991
RSCorr: 206 0
RSUnCorr: 0 0
Bearer 1
OHF: 38350 0
OHFErr: 0 0
RS: 229728 0
RSCorr: 0 0
RSUnCorr: 0 0
Retransmit Counters
rtx_tx: 1204870 0
rtx_c: 585597 0
rtx_uc: 72019 0
G.INP Counters
LEFTRS: 2081 0
minEFTR: 28826 0
errFreeBits: 284375908 0
Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 34156107 0
Data Cells: 45225 0
Drop Cells: 0
Bit Errors: 0 0
Bearer 1
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 0 0
Data Cells: 0 0
Drop Cells: 0
Bit Errors: 0 0
ES: 405 201
SES: 183 0
UAS: 1226 1120
AS: 616
Bearer 0
INP: 43.00 0.00
INPRein: 0.00 0.00
delay: 0 0
PER: 0.00 9.08
OR: 0.01 28.16
AgR: 28863.69 2887.32
Bearer 1
INP: 2.50 0.00
INPRein: 2.50 0.00
delay: 0 0
PER: 16.06 0.01
OR: 47.81 0.01
AgR: 47.81 0.01
Bitswap: 17/21 1/1
Total time = 3 days 17 hours 48 min 36 sec
FEC: 2501862783 331
CRC: 9132 291
ES: 405 201
SES: 183 0
UAS: 1226 1120
LOS: 6 0
LOF: 9 0
LOM: 0 0
Latest 15 minutes time = 3 min 36 sec
FEC: 28 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 4287176 0
CRC: 786 0
ES: 29 0
SES: 15 0
UAS: 210 196
LOS: 1 0
LOF: 1 0
LOM: 0 0
Latest 1 day time = 17 hours 48 min 36 sec
FEC: 52303095 18
CRC: 2742 11
ES: 118 10
SES: 64 0
UAS: 389 361
LOS: 2 0
LOF: 3 0
LOM: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 24145976 111
CRC: 693 97
ES: 40 60
SES: 20 0
UAS: 184 170
LOS: 1 0
LOF: 2 0
LOM: 0 0
Since Link time = 10 min 15 sec
FEC: 206 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
If you got this far, the only indication of the latest drop is FEC errors going insane and G.INP plotting it.
ES stays low.
SNRM stays level.
A long time ago I had an issue (on ADSL) caused by a faulty PSU in some LED lights. This was clearly visible in the SNRM decreasing over a 30 minute period as the PSU got hot. I don't see anything like this here.
I'm convinced it must be a line issue, but do you agree? How do I persuade my ISP/BT to check further without charging me!
If you got this far, please please any suggestions on how to get this sorted!
@mrpointy broadband quality monitor created. Thanks for the suggestion. I’ve been using uptimerobot but it isn’t really telling me anything I don’t already know.
My ISP are a small U.K. based one who I rate highly so I’m a bit loathed to change. This is the first time I’ve had problems getting them to progress something, although I suppose I’ve not had to as things have been fine up to now. Basically they want it to get worse first, which may of course never happen.
@gromm I’m sure it’s something like this, but how do I get them to check further without their line tests giving an error?
I’ve also just bought a Zyxel VMG1312-B10A router to try in place of my current Billion 8800NL V1. Same Broadcom chipset, but may make a difference. I’ve already tried a Vigor 130 without success so not hopeful but for a tenna worth a shot.
My ISP are a small U.K. based one who I rate highly so I’m a bit loathed to change. This is the first time I’ve had problems getting them to progress something, although I suppose I’ve not had to as things have been fine up to now. Basically they want it to get worse first, which may of course never happen.
@gromm I’m sure it’s something like this, but how do I get them to check further without their line tests giving an error?
I’ve also just bought a Zyxel VMG1312-B10A router to try in place of my current Billion 8800NL V1. Same Broadcom chipset, but may make a difference. I’ve already tried a Vigor 130 without success so not hopeful but for a tenna worth a shot.
Edited by page3 on Saturday 18th January 13:36
Bikerjon said:
I assume your ISP are giving you the £130 callout threat if no fault found by openreach? You have already tried way more than most people would ever do to get openreach to investigate! The problem with being technical is sometimes it's tempting to over-analyse these problems when most people would simply go to the ISP and demand it is fixed!
The only thing I would say is make sure you use a BT approved modem. In my experience the most stable are the old white openreach boxes. Otherwise any recent Draytek with the BT approved firmware. VDSL does drop every so often, so it really depends how frequent the issue typically is.
Correct on the callout threat. Dropping 2-3 times a day, every day.The only thing I would say is make sure you use a BT approved modem. In my experience the most stable are the old white openreach boxes. Otherwise any recent Draytek with the BT approved firmware. VDSL does drop every so often, so it really depends how frequent the issue typically is.
They did send someone, replaced the (perfectly fine) master socket. Tried to charge me, but the ISP contested it.
I am using a Billion 8800NL, but have tried a Vigor 130. I've just got hold of the old BT white one, unlocked it to try.
An update though - internet went down five minutes ago, while I was in. I tried to do a quiet line test but couldn't even get a dialling tone. Nothing for 5 minutes until both the phone and internet came up. That's got to be a line issue!
Edited by page3 on Saturday 18th January 18:16
Harpoon said:
No dial tone? Report it as a PSTN fault as well.
Will do.I hadn't realised the phone line was going down too, as its intermittent enough that I'm usually out, plus each outage is only a few minutes, giving little time to rush to the phone to check. The wife now tells me the lack of dial-tone has been randomly going on for quite a while. She thought it was the phone, but we swapped that yesterday just to rule out interference from the old one.
It's gone down again tonight. That's four times today.
Speed is ok right now, but DLM will screw it up overnight, as per usual.
FECing ridiculous.
Edited by page3 on Saturday 18th January 23:01
Here is the latest graph
I swapped the Billion 8800NL to a spare Huawei HG612 which does seem to hang on to the connection a bit better (from the limited time its been up). Still seeing the same bursts of noise though.
During these periods of noise I cannot dial out with the land line. The dial tone never goes away and no connection can be made. I've tried three different phones (including a corded one) and via the master socket and test socket (via microfilter).
My ISP simply say the line test comes back OK. They will ask Openreach to send out an engineer on my request, but i'll be charged if no fault found. This is very likely as its so intermittent!! They also need me to be present, although I've asked them to check the exchange/cabinet first - no can do.
Any suggestions? I'm out of ideas!
I swapped the Billion 8800NL to a spare Huawei HG612 which does seem to hang on to the connection a bit better (from the limited time its been up). Still seeing the same bursts of noise though.
During these periods of noise I cannot dial out with the land line. The dial tone never goes away and no connection can be made. I've tried three different phones (including a corded one) and via the master socket and test socket (via microfilter).
My ISP simply say the line test comes back OK. They will ask Openreach to send out an engineer on my request, but i'll be charged if no fault found. This is very likely as its so intermittent!! They also need me to be present, although I've asked them to check the exchange/cabinet first - no can do.
Any suggestions? I'm out of ideas!
Harpoon said:
Are IDNet your PSTN provider? Either way, did you log a PSTN fault (ie not a broadband) faulty that you cannot make voice calls at times?
Yes and yes.They are offering to take a call from the engineer to help explain the issues, but are still saying the line comes back as 'ok' and so a charge may be made. I need to agree to this before they arrange a callout. It's another 1/2 day off work for me too.
Coin Slot. said:
Assume they've checked your termination at the green cabinet?
Unfortunately not!They've only checked the master socket (which I knew was fine), swapped it to new socket and faceplate (pinching my posh filtered faceplate). I'd already tried two faceplates and two filters.
They ran a 5 minutes test, which came back fine, as I knew it would - being an intermittent fault.
An engineer will have to wait until next week as too busy work-wise to take more time off.
I have swapped the Billion 8800NL (which has been working great for years) for an old HG612. This is the third modem I've tried (the other being a Draytek Vigor 130).
The HG612 appears to hold on to connection with a much lower noise margin. It also shows SNR margin fluctuations, where as the Billion was almost always level. Far less FEC error that the billion (although still lots of spikes).
I still don't think this is local interference, but a line problem which I'm seeing. I still cannot always get an outside line - dial tone never stops. Really intermittent though.
Last 24 hours. Line drop around 10pm and again around 2am (DLM). Still not managed more than 2 days without drop in the last 3 months.
Here's DSLStats SNRM last two days
Far lower margin, it was near 6db for ages before plummeting to just over 2.5 and only recovering to 3. You can also see the line drop at 10pm and the resync at 2am.
I have swapped the Billion 8800NL (which has been working great for years) for an old HG612. This is the third modem I've tried (the other being a Draytek Vigor 130).
The HG612 appears to hold on to connection with a much lower noise margin. It also shows SNR margin fluctuations, where as the Billion was almost always level. Far less FEC error that the billion (although still lots of spikes).
I still don't think this is local interference, but a line problem which I'm seeing. I still cannot always get an outside line - dial tone never stops. Really intermittent though.
Last 24 hours. Line drop around 10pm and again around 2am (DLM). Still not managed more than 2 days without drop in the last 3 months.
Here's DSLStats SNRM last two days
Far lower margin, it was near 6db for ages before plummeting to just over 2.5 and only recovering to 3. You can also see the line drop at 10pm and the resync at 2am.
jesusbuiltmycar said:
This... I have recently had issues with dropping connections after heavy rain/bad weather; having Nest security cameras means that I get a notification that a cmaer is offline as soon as the connection drops.
BT came out within 48 hours of me reporting issues (my BT contract guranteees minimum of 52Mb/s); they checked the wiring in the house (no issues) and then checked the connection back to the green box. The technician changed/replaced something in the green box and the internet has been fine since but he also diagnosed an issue between my house and the junction at the end of my drive and BT plan to replace the cable in the next few days.
Unfortunately the BT engineer I had simply checked the master socket (was fine) and replaced it anyway. They didn't check the cabinet, exchange or pole.BT came out within 48 hours of me reporting issues (my BT contract guranteees minimum of 52Mb/s); they checked the wiring in the house (no issues) and then checked the connection back to the green box. The technician changed/replaced something in the green box and the internet has been fine since but he also diagnosed an issue between my house and the junction at the end of my drive and BT plan to replace the cable in the next few days.
They now want to charge me if "no fault found" which is quite possible considering the intermittent nature of the fault. Has anyone been charged and contested it?
jesusbuiltmycar said:
If you dont want to risk having to pay (and I don't blame you for not trusting them to find the fault) it may be worth changing your ISP to BT and selecting one of theier packages that guarantees a level of service - you'll be amazed how quickly they wil sort it out.
I did think about this, but I could just be getting myself in to a whole lot more trouble!BT's website seems to suggest I can either get SUPERFAST FIBRE ESSENTIAL (16 - 26 Mb, guaranteed 12Mb) for a 24 month contract. No idea where the 16 Mb comes from as that's below their Range B impacted line estimate - and I get 28 mbps right now anyway. Also I'd love to get 16 Mb, I suppose they mean 16 mbps but that's not what it says! For a bit more I can get SUPERFAST FIBRE (Average speed 50Mb) which is ridiculous - I'll never get that.
With IDNet I get around 28/3 which is brilliant for the line length. Just wish it was stable like it had been for years before now.
jesusbuiltmycar said:
Does the Superfast Fibre include a guarantee? I only found out about the guarantee recently. I have a package which has been renamed to 'BT Halo' it offers a mesh network of wifi disks to cover the home and they guarantee 50Mbps downlink.
Don't know. BT tried to call me last night (I guess a sales call following on from looking on-line) but my line went down!Anyway, usual 2am resync (with no change to anything) and a drop at 8:40am today during which as usual I couldn't dial out as dial tone wouldn't break. ISP is still saying "no fault" and wants me to agree to pay if no fault found by engineer.
@gottans Don’t think so, but I’ll check tomorrow in daylight.
As I’ve hit an impasse with IDNet (who basically are saying live with it) I’m thinking of moving to Zen which is £16/month cheaper anyway! Does anyone know when you move provider is anything actually changed at the exchange or cabinet? Can I request it, or should I keep my current issues to myself? This might be be way to get a clearer line?
As I’ve hit an impasse with IDNet (who basically are saying live with it) I’m thinking of moving to Zen which is £16/month cheaper anyway! Does anyone know when you move provider is anything actually changed at the exchange or cabinet? Can I request it, or should I keep my current issues to myself? This might be be way to get a clearer line?
Digger said:
I’m with Zen & they are ok. I would personally approach your isp with your stats / logging evidence first.
You have told them the phone line loses its connection as well?
I’ve approached them time and time again. I’ve given detailed stats and graphs 24/7 for the last month, during which my connection maximum uptime has been 15 hours. I’ve done detailed internal diagnostics, master socket and filter has been replaced. I’ve swapped everything, several times - cables, micro filters, faceplates, routers, switches, modems, power supplies - for example I’ve tried four modems and three phones!You have told them the phone line loses its connection as well?
In their last email they simply state the line test comes back fine, the fault is too intermittent, they cannot do a longer term line test and an Openreach engineer will charge if they find no fault. The fact that I have 3 years previous with them during which the connection was stable is ignored.
I’d pay for an engineer to check the cabinet, pole and exchange and fix the issue but not for them to come to my home, plug in their tester, declare all is fine and sod off.
The isp is totally disinterested in offering any further assistance, unless the connection gets worse. Costs - £47/month for 26/3 and a phone I can sometimes dial out on.
Digger said:
Approach Ofcom?
Only option left I think.Apparently I can ask my ISP for a Deadlock Resolution letter, which I can take to the Ombudsman. Initially raised the issue 4th October 2019 and I've been running around ever since, having spent £100+ on parts to help them diagnose the issue. "live with it" isn't really a satisfactory resolution.
Another day, another three drops (without warning).
I've also re-wired everything (for the umpteenth time) adding a Tacima 6 Way Mains Conditioner and also my fourth modem (a Zyxel VMG1312-B10A).
As expected, no difference other than the Zyxel gets a slightly faster sync.
I'm going to migrate to Andrews & Arnold, who say they'll take on a line with a fault and sort it. If they can get someone out to the cabinet/pole/exchange I expect they'll find something corroded somewhere.
I've also re-wired everything (for the umpteenth time) adding a Tacima 6 Way Mains Conditioner and also my fourth modem (a Zyxel VMG1312-B10A).
As expected, no difference other than the Zyxel gets a slightly faster sync.
I'm going to migrate to Andrews & Arnold, who say they'll take on a line with a fault and sort it. If they can get someone out to the cabinet/pole/exchange I expect they'll find something corroded somewhere.
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