cancel
Showing results for 
Search instead for 
Did you mean: 

I think we've got a fault!

wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

I think we've got a fault!

Hi there,
I've noticed that there seems to be a serious fault with our line. At around 6PM every day, the SNRM will drop from 6dB to about 2dB. This is not the drop associated with it getting dark. In 10 seconds, the SNRM drops from 6 to 2dB.
This causes the speed to drop from about 6Mb to 1 or less (or the connection stops completely). To get the connection to be remotely useable, I then have to restart the router and that causes the sync speed to drop from an average of about 8000Kbps to about 6000Kbps.
I thought this may have been a problem with our internal wiring, so I connected the router to the test socket, but it hasn't made any difference.
I have attached some graphs to show the problem.
97 REPLIES
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

I had to restart the router because the internet just stopped working.
We've now gone from a sync of 8.2Mb to a sync of 7Mb. This is utterly ridiculous!
Community Veteran
Posts: 5,172
Thanks: 480
Fixes: 20
Registered: 10-06-2010

Re: I think we've got a fault!

What gets switched on at 6pm? If it's not something in your house, it could be in a neighbouring house. Possibly a REIN fault: http://www.kitz.co.uk/adsl/rein.htm
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Nothing gets switched on at 6 that would do this. It's often at this sort of time (probably between 5-Cool but sometimes it happens in the afternoon.
REIN does seem likely, but there is nothing here that would be causing that (I have made sure of this many times before).
I think what we need is a REIN engineer and/or the whole line to be changed as I suspect there is a split somewhere, allowing more interference than normal.
Superuser
Superuser
Posts: 12,600
Thanks: 3,874
Fixes: 25
Registered: 22-08-2007

Re: I think we've got a fault!

Susie/Alec,
This step change is so marked that it is highly likely that it s being caused by a piece of faulty equipment somewhere nearby.  It would be helpful if you could leave the router alone for one night when this happens to monitor the return to normal of the SNRM.  Bouncing your router when this happens will only serve to cloud the issue and thus fault resolution.  The DLM will see an unstable line, raise your target SNRM and slow your synch speed.
Router stats can be configured to capture graphs continually so you can set it up and look back at the results later.
I have seen similar marked steps caused by street lighting, poor internal phone wiring, failing power supply units on CCTV systems and passing electric trains.  This all took 6 months of detailed careful monitoring, elimination of all possible sources of REIN along with PN battering BTOR until after 18 visits, the best pairs (which showed least suspectibility to the passing trains) were identified and allocated to my circuit.  First fully follow the slow connection guidance (see here: http://community.plus.net/forum/index.php/topic,96155.0.html).
How have you made fully sure that there is no REIN.  Do you have access to REIN detection equipment?
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Hi there,
In my own home, I have used a radio, tuned to the Kitz recommended frequencies and I have walked around and turned everything off that was flagged up on the radio. It didn't make any difference.
I have even turned off everything except the router and a PC (with the monitors turned off) and turning things on didn't cause the SNRM to drop. I thought the PC may have been the problem, but I monitored the SNRM from another PC and that made no difference either.
To me, this points to interference outside my home.
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Quote from: townman
This step change is so marked that it is highly likely that it s being caused by a piece of faulty equipment somewhere nearby.  It would be helpful if you could leave the router alone for one night when this happens to monitor the return to normal of the SNRM.  Bouncing your router when this happens will only serve to cloud the issue and thus fault resolution.  The DLM will see an unstable line, raise your target SNRM and slow your synch speed.

I understand and I would have done that, but the internet becomes so unusable that nobody can use it for anything (even browsing). I will try and leave it on tonight.
The DLM isn't really a problem as my target SNRM is permanently fixed to 6dB, but I understand your point nonetheless.
Thanks for your help so far.
Edit: After restarting the router last night (sorry!) the SNRM returned to 6dB, but obviously at a much lower sync speed of 7001Kbps. From here, the SNRM dropped again, all the way down to 3dB (but more gradually, although still quite quickly - like in the space of an hour or so - it's worth mentioning that it was already dark at this point, so I don't think it was that). This caused a ridiculous amount of errors to be created:
Quote
Uptime: 0 days, 12:26:36
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 888 / 7,001
Data Transferred (Sent/Received) [MB/GB]: 164.74 / 3.61
Output Power (Up/Down) [dBm]: 12.8 / 0.0
Line Attenuation (Up/Down) [dB]: 21.7 / 43.5
SN Margin (Up/Down) [dB]: 11.7 / 7.3
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): -
Error Seconds (Local/Remote): 8,020 / 0
FEC Errors (Up/Down): 41 / 38,633,460
CRC Errors (Up/Down): 0 / 457,844
HEC Errors (Up/Down): 0 / 246,939

If we're getting this many errors at this sync speed, there is never any way we're going to be able to get the 8+ Mb we were getting before; the errors will just be too much for the connection to take.
I think the best solution in the end will be to do a line change (probably a D-Side change) keeping in mind townman's advice, but who knows if BTO will go for this.
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Right, the PC with RouterStats is being left on all day and night. I have set the graph so it shows 25 hours of plots, so we can see a full day of SNRM history.
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Should I restart the router again so it connects near to 8.5 (as the SNRM is back to normal - for now) or should I leave it at 7?
Superuser
Superuser
Posts: 9,773
Thanks: 1,151
Fixes: 63
Registered: 06-04-2007

Re: I think we've got a fault!

I'd be inclined to leave the sync at the current lower value - the SNRM variations should still show and hopefully the connection will remain usable through the worst period..
David
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Quote from: spraxyt
I'd be inclined to leave the sync at the current lower value...

I have done so. Any comment, Plusnet?
Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: 13-07-2012

Re: I think we've got a fault!

I'd certainly leave it stable to establish the exact pattern, it would be worth running through our faults wizard - http://faults.plus.net so our faults team can help investigate.
wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

wykehamhouse
Grafter
Posts: 260
Registered: 01-02-2013

Re: I think we've got a fault!

Fault raised. Can we try and get this solved as quickly as possible!
Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: 13-07-2012

Re: I think we've got a fault!

We always try, our fault team will need to test your line first.