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Sudden speed drop - QLN

Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Sudden speed drop - QLN

Hello guys,

 

I have experienced a sudden drop of about 6 mbs and I cannot explain how this has happen.

1st event has pushed a resync event and the speed down to 74000 from 79999 for couple of hours but the max speed bumped back to 84000 after couple of hours and I was able to get 79400 after a resync

2nd episode now the 74000 speed is permanent while the max speed is around 75000

 

QLN shows a gap missing between tone 1964 and 2791 which should be the normal upstream all set to -160dbm

HLOG shows normal.

I can upload some other stats if required. I know that I am lucky to get even 74000 after years of being banded down to 60 but I fear it might go that low again.

 

Otherwise my connections stats are:

xdslctl info --stats
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 15086 Kbps, Downstream rate = 74810 Kbps
Bearer: 0, Upstream rate = 15101 Kbps, Downstream rate = 74190 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): 3.1 5.9
Attn(dB): 19.5 0.0
Pwr(dBm): 12.6 7.4

VDSL2 framing
Bearer 0
MSGc: -6 25
B: 243 237
M: 1 1
T: 0 64
R: 10 16
S: 0.0000 0.5014
L: 19403 4053
😧 8 1
I: 254 127
N: 254 254
Q: 8 0
V: 0 0
RxQueue: 84 0
TxQueue: 21 0
G.INP Framing: 18 0
G.INP lookback: 21 0
RRC bits: 0 24
Bearer 1
MSGc: 154 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 6.4000 0.0000
L: 40 0
😧 3 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 84039
OHFErr: 1 58
RS: 3854352824 1014784
RSCorr: 13341966 350
RSUnCorr: 0 0
Bearer 1
OHF: 6307112 0
OHFErr: 0 0
RS: 63070506 0
RSCorr: 136 0
RSUnCorr: 0 0

Retransmit Counters
rtx_tx: 2899830986 0
rtx_c: 1895304 0
rtx_uc: 4 0

G.INP Counters
LEFTRS: 6 0
minEFTR: 74172 0
errFreeBits: 114185053 0

Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 1512150461 0
Data Cells: 294452908 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: 1 57
SES: 0 0
UAS: 29 29
AS: 101339

Bearer 0
INP: 51.00 0.00
INPRein: 1.00 0.00
delay: 0 0
PER: 0.00 8.05
OR: 0.01 30.79
AgR: 74266.30 15131.66

Bearer 1
INP: 4.50 0.00
INPRein: 4.50 0.00
delay: 3 0
PER: 16.06 0.01
OR: 79.68 0.01
AgR: 79.68 0.01

Bitswap: 28305/28305 646/646

Total time = 1 days 4 hours 9 min 28 sec
FEC: 13341966 350
CRC: 1 58
ES: 1 57
SES: 0 0
UAS: 29 29
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 9 min 28 sec
FEC: 11386 5
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 17870 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 4 hours 9 min 28 sec
FEC: 279583 53
CRC: 0 3
ES: 0 3
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 13062383 297
CRC: 1 55
ES: 1 54
SES: 0 0
UAS: 29 29
LOS: 0 0
LOF: 0 0
LOM: 0 0
Since Link time = 1 days 4 hours 8 min 57 sec
FEC: 13341966 350
CRC: 1 58
ES: 1 57
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
>

13 REPLIES 13
JOLO
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 1,149
Fixes: 77
Registered: ‎06-08-2018

Re: Sudden speed drop - QLN

@Justinian,

 

I've run a few tests on the connection and can't see any reason for the dips that have occurred, but I wonder if your throughput is being affected comparative to the sync speeds you've posted. I only ask because sync on your GEA tests shows 70.4 down, 15.1 up, with an exchange line rate of 66883.

Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Hi Joe,

 

Indeed the throughput is around 60mbit/s but that has always been the case on this line.

The sync on this line has been aroung 79mbs with max sync rate around 83-84 from the last intervention on the line. This drop has happened at the same time with the bout of warm weather we had during and before the easter weekend.

What about the tones missing in the QLN graph ?

 

python speedtest.py 

Retrieving speedtest.net configuration...

Testing from Plusnet (redacted)...

Retrieving speedtest.net server list...

Selecting best server based on ping...

Hosted by GTT.net (Slough) [27.96 km]: 24.281 ms

Testing download speed................................................................................

Download: 59.53 Mbit/s

Testing upload speed................................................................................................

Upload: 13.59 Mbit/s

LaurenB
Plusnet Help Team
Plusnet Help Team
Posts: 2,577
Thanks: 508
Fixes: 131
Registered: ‎07-12-2017

Re: Sudden speed drop - QLN

Hi @Justinian, with regards to the QLN graph it's hard to say what's caused this as there is no time stamp and we aren't seeing any drops in circuit (other than a drop on Thursday around 2pm).

 

Can you run a speed test using speedtest.btwholesale.com and send us a screenshot of the results.

 

I'd also advise connecting your router to the test socket for the time being if not already.

If this post resolved your issue please click the 'This fixed my problem' button
 Lauren Barry
 Plusnet Help Team
Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Hello Lauren,

 

My current IP profile is set to 64.94 Mbit/s

 

Just uploaded the screenshot but keep in mind at this time of the day the throughput is known to be lower.

TheMightyAJ
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 2,511
Fixes: 126
Registered: ‎26-03-2018

Re: Sudden speed drop - QLN

Hi @Justinian,

Thanks for providing this info. Upon retesting the line and reading through the thread, though the sync speed has dropped, this doesn't appear to be a fault with service as it's still performing within the estimated speed range for your line.

As this is the case, it's hard to say what caused the speed to start performing at a lower rate than it had being do so up until this point and unfortunately there's nothing we can really do to boost the speed again from our end of things. If you're currently plugged into the test socket then I'd recommend leaving the router plugged into this setup if that's something you're happy to do. I'd also recommend connecting through Ethernet cable where possible, as this will always provide a more stable and speedy connection than Wi-Fi can offer.

As a side note, the results included in the speedtest run through BT Wholesale looked a little low and I believe this may be down to the BT Wholesale speedtest itself, as it's known to not always accurately reflect the speed you're receiving from time to time. It may be worth rerunning this test using an alternative site, such as speedtest.net.

If there's any further discrepancies or if you experience any further issues then please don't hesitate to get back in touch with us and we'll be happy to assist further.

If this post resolved your issue please click the 'This fixed my problem' button
 Alex H
 Plusnet Help Team
Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Hey all thanks for you replies.

 

There has been a change in the missing gap in the QLN graph, now the gap is starting at tone number 2272 and it finishes with tone 2791. Even so, there has been no change in the DS/US speeds. I am still wondering what is causing this gap with all the tones been impacted and showing a -160db. Thinking about just some noise or some weird radios or harmonics in that range.

TheMightyAJ
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 2,511
Fixes: 126
Registered: ‎26-03-2018

Re: Sudden speed drop - QLN

Hi @Justinian,

It's hard to say for sure what the cause of the issue is. Coincidentally, I re-ran testing on your line this morning to see if we could detect any further issues and the initial test result suggested a potential phone fault. However, upon further testing to determine if this was external or internal the same result was not returned. As this is the case, I'd like to ask if you have a phone handset plugged in and if you have noticed any issues specifically with the landline services?

If you haven't then it's nothing to worry about, we can still offer further suggestions and support to help improve your services. To that end, are you able to confirm if you've set your router up within the test socket as of yet? If it is set up within the test socket, is it the only thing plugged in?

If this post resolved your issue please click the 'This fixed my problem' button
 Alex H
 Plusnet Help Team
Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Thanks,

 

I can confirm the modem is plugged in straight into the test socket. Nothing else has been plugged in. No micro-filter. Unfortunately I do not own a landline handset anymore but I'll try to get a lineman butt tester of amazon as most of the landline phones are wireless these days and the wireless bit is also pushing a hiss in the headset making it almost impossible to listen to the line.

TheMightyAJ
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 2,511
Fixes: 126
Registered: ‎26-03-2018

Re: Sudden speed drop - QLN

Hi @Justinian,

Thanks for confirming this. Just to clarify, when we refer to the test socket in the property, we mean that there should be a phone socket beneath the faceplate of the master phone socket, which is there for testing purposes. Due to the nature of the test socket, it would require that the router be plugged into it via a mirco-filter and so it may be worth seeing if you are able to access this specific component of the socket. For reference, we have a handy guide on how to locate and access the test socket, which can be found here.

If this post resolved your issue please click the 'This fixed my problem' button
 Alex H
 Plusnet Help Team
Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Hi,

 

Yes I've removed the faceplate and plugged the cable straight in. Had made no difference so far, are you finding anything related to the faceplate filter ?

TheMightyAJ
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 2,511
Fixes: 126
Registered: ‎26-03-2018

Re: Sudden speed drop - QLN

Hi @Justinian,

I've retested your line this afternoon and I'm no longer detecting the aforementioned potential phone fault. If the router has only recently been plugged directly into the test socket then this may indicate an issue with the master socket faceplate, though before we reach that conclusion I would advise that it may be worth leaving the router in its current setup for the next few days and monitoring how things go.

If this post resolved your issue please click the 'This fixed my problem' button
 Alex H
 Plusnet Help Team
Mustrum
Community Veteran
Posts: 3,563
Thanks: 1,059
Fixes: 77
Registered: ‎13-08-2015

Re: Sudden speed drop - QLN

@Justinian  How are you able to plug the router into the test socket without a micro filter? The connectors are different.

Justinian
Rising Star
Posts: 70
Thanks: 12
Fixes: 1
Registered: ‎02-07-2013

Re: Sudden speed drop - QLN

Think I have an older faceplate. The same cable which fits in the faceplate fits in the backend as well. And I have a cable which has the BT plug on one end and the normal RJ11 on the other.