cancel
Showing results for 
Search instead for 
Did you mean: 

Line help needed

rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Line help needed

Hi Guys,
Having a problem with my line.
Up until Saturday I was synced at 8128 but when my line went mental the attenuation jumped from 14 to 44 and the noise margin dropped to -1.8 then router rebooted. When it restarted it had a problem holding a sync I managed to hold a sync after a short time and now I am synced again at 8128, attenuation at 14 and noise at 4.8 and its holding, Since Saturday my throughput is only 2Mb how long do I have to wait for the profile to match the sync or can you do put my line back in training and reset the profile?
Also I just had a new line installed today (Well second activated as already installed) and well I am shocked at the difference between then BT line and PN line, Both lines goes directly to the same exchange (no cabinets as small village exchange), yet the BT synced at 8128 with a noise margin of 10.2 but my PN line only syncs at 7.6 with a noise margin of 6 with an intermittent noise drop to 4.5 or lower on an almost daily basis. This interference is not wiring in the house and I have done an intensive testing around my house switching everything off except the router and laptop when it drops and its still there, so the interference is outside somewhere between me and the exchange. Any way we can get the interference on my PN line investigated.
I was going to open a ticket but PN seems to have stopped me doing that.
Regards
22 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 17,641
Thanks: 535
Fixes: 159
Registered: 05-04-2007

Re: Line help needed

Hi there,
Quote
Up until Saturday I was synced at 8128 but when my line went mental the attenuation jumped from 14 to 44 and the noise margin dropped to -1.8 then router rebooted.

Do you know what caused this?
Quote
now I am synced again at 8128, attenuation at 14 and noise at 4.8 and its holding,
&
Quote
my PN line only syncs at 7.6 with a noise margin of 6

Are both of these statements about the Plusnet line?
I'll go run a line test and see what's going on.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
Plusnet Staff
Plusnet Staff
Posts: 17,641
Thanks: 535
Fixes: 159
Registered: 05-04-2007

Re: Line help needed

The line isn't looking hugely stable at the moment, have you noticed these disconnections?

Your line is synced at 8128 now, which means the profile should increase to 7150, however as the increase is only around 9% (from 6500 to 7150) the profile change can take 96 hours on 20CN lines.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

Right sorry forgot to mention.. To get the 8128 line, I tweaked the the 7680 line with the router to increase speed(SNR mod). It worked fine for a ages until saturday. I have no idea why the sudden increase in line attenuation or drop in SNR but the wife was on a call and it was cut off at the same time. I did asked the BT guy who was out today for the new line and he did say if someone was at the exchange they could have been replacing equipment at that time.
Quote
Your line is synced at 8128 now, which means the profile should increase to 7150, however as the increase is only around 9% (from 6500 to 7150) the profile change can take 96 hours on 20CN lines.

As for the line now, my throughput is only 1.8Mb so this means the profile is 2000. That is what the PN current line speed says I am.
Plusnet Staff
Plusnet Staff
Posts: 17,641
Thanks: 535
Fixes: 159
Registered: 05-04-2007

Re: Line help needed

Sorry, complete schoolboy error on my part. Give me 2 minutes and I'll go change that now, the profile on BT's side is showing as 6500 from the test I performed.
You might need to log in to your router and disconnect/reconnect before you see an increase in speed.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

Cool, will try a disconnect shortly
Any ideas about the noise on the line or how to clear the line to improve quality a bit.
Plusnet Staff
Plusnet Staff
Posts: 17,641
Thanks: 535
Fixes: 159
Registered: 05-04-2007

Re: Line help needed

Is there any audible noise on the line at all? I'm going to assume not as you've been pretty thorough in your posts.
I've just performed a line test on the phone line itself which isn't showing any issues either.
With the attenuation of 14, I'd expect your line to be syncing at the full 8128 even at a 6db target.
Could you try a resync, during daylight hours after you've removed the tweaks and see what the line connects at then?
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

I have done a quiet line test and it is quiet
Quote
With the attenuation of 14, I'd expect your line to be syncing at the full 8128 even at a 6db target.

This is what I would expect. The new line is doing this.  Shocked
I will remove the tweak and re sync tomorrow and post the results.
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

Removed SNR tweak and re synced at 7712 with snr at 6.1
Stats:
Quote
Max:    Upstream rate = 1064 Kbps, Downstream rate = 8340 Kbps
Channel:        FAST, Upstream rate = 448 Kbps, Downstream rate = 7712 Kbps
Link Power State:      L0
Mode:                  G.DMT
TPS-TC:                ATM Mode
Trellis:                ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        6.1            23.0
Attn(dB):        14.0            7.0

I uploaded what I monitored last night. Forget the first big drop, that was me but the one near the end. Last night was a small drop and did not last long but it happens at different times and can last hours. I also checked the other line at the same time as this drop and the other line was not affected.
Superuser
Superuser
Posts: 11,066
Thanks: 2,422
Fixes: 21
Registered: 22-08-2007

Re: Line help needed

Quote from: rackstraw2006
Quote
Max:    Upstream rate = 1064 Kbps, Downstream rate = 8340 Kbps


Is this a 20CN or 21CN line?  See here - http://www.kitz.co.uk/adsl/adslchecker.php - for what is available.
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

20cn.. No ADSL2+ or FTTC/FTTP here. Not until 2017 anyways
Quote
Distance:
Direct: 602 metres (appx)
By Road: 0.8 km
Status
ADSL enabled: April 6, 2005
DSL Max enabled: March 31, 2006
21CN WBC (Broadband) Not available
21CN due : (PSTN) info N/A
FTTC Not available
SDSL enabled : Not Enabled
Fixed ADSL: 2048 kbps (2 Mb)
DSL Max:  8000 kbps (8 Mb)
21CN WBC : Not Available
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

Just an update on the SNR drop..  Sad
Superuser
Superuser
Posts: 11,066
Thanks: 2,422
Fixes: 21
Registered: 22-08-2007

Re: Line help needed

That looks like a clear case of something being switched on at a 14:50 and off at 17:30.
What is the sample interval?  Every 10 seconds would be useful.
The "dark hours" SNRM transition looks absent, which is good news.
rackstraw2006
Grafter
Posts: 63
Registered: 01-07-2013

Re: Line help needed

I am running the line monitor for the next 24 hours at a 30 second interval.
I have been at this for months now and had everything unplugged and its still there. Now I can eliminate some things close to me. My phone line goes out my back garden across the next door garden to the poll in the field behind my house. This is the same route my other line takes. As the other line is not affected then the problem I would think would be further away and as its not close, I have no way of tracing it as I am not sure the route the line takes after the next poll as it goes underground.
Since I got my other line I have a question I was wondering about. Is it possible to get BT to climb the poll out my back and disconnect it from the dodgy line and move it to another one.
Superuser
Superuser
Posts: 11,066
Thanks: 2,422
Fixes: 21
Registered: 22-08-2007

Re: Line help needed

Have you got ADSL broadband on both lines?
I guess it out to be possible to get BTOR to swap the d&e-side pairs between the two lines... but how is a different matter!