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Unstable Connection

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Unstable Connection

Can someone look at my line as it has become unstable with frequent disconnections since yesterdays heavy showers.

I got in touch with Plusnet customer services but they were unwilling to intervene as no faults were showing, he did confirm that there were 7 disconnections that afternoon.

I explained there was some cracking on the line during the heavy showers when I received an incoming call. When I try the quiet line test it is ok now.

Today the connection dropped with an incoming phone call so I think there is some fault. That makes 3 disconnections today.

The router is connected directly to the master socket by a short cable with no extended wiring.

 

44 REPLIES
Plusnet Help Team
Plusnet Help Team
Posts: 12,776
Thanks: 108
Fixes: 32
Registered: 27-04-2007

Re: Unstable Connection

Hi there,

 

Both broadband diagnostics and checks on the line aren't finding any obvious issues still.

 

I'd advise making sure you've followed the steps shown on our online troubleshooter: http://faults.plus.net/

 

Once you have that will allow you to report the issue with us, I suspect in the long run an engineer will need to resolve this one for us.

If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

Thanks for the response Adam.

I will use the faults trouble shooter the next time I get the obvious disconnection problems as all is stable at the moment.

Over the weekend I used 2 other routers, different filters, and noticed the upload snr was around 4db for some time, lower than in the past.. Then I had another re-sync and the upload connection rate was just 88 so it appears to be affecting the upload frequency area. Then I noticed the margin increased from 4db to 9db so I thought the line had settled down but had a phone call on Sunday evening which caused the connection to drop again.

 

The recent drops have had the affect of the DLM increasing the tsnr to 9db. I will see how this weeks weather affects the line and do the faults if I can at the same time.

ADSL line status

Connection information

Line state Connected
Connection time 0 days, 15:59:39
Downstream 3,331 Kbps
Upstream 440 Kbps

 

ADSL settings

VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 9.4 dB / 6.2 dB
Line attenuation (Down/Up) 54.5 dB / 26.5 dB
Output power (Down/Up) 18.4 dBm / 12.4 dBm
Loss of Framing (Local) 11
Loss of Signal (Local) 1
Loss of Power (Local) 0
FEC Errors (Down/Up) 193355 / 0
CRC Errors (Down/Up) 1205 / N/A
HEC Errors (Down/Up) N/A / 154000
Error Seconds (Local) 755

 

 

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

I have now reported a fault as there were more disconnections yesterday when the phone rang.

While I wait for the fault findings I have been monitoring the line this morning using "dslstats" with the Plusnet router. All was stable until I used the phone and the upstream  snm dropped from 6db to nearly 0db. I used the quiet line test and noticed some noise at the beginning which stopped after a few seconds. The connection hasn't dropped yet but the last re-sync halved the upstream speed to 442kbps so probably able to hold on to the lower sync speed.

The graph below shows the dips in the snm when the phone was used and I did unplug the digital phone and used a corded phone but it made no difference. The error corrections have also massively increased since I used the phone.

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

The connection has continued to loose sync during heavy showers and some phone calls. Most likely to drop when the upstream connects at a higher sync rate. Anything above 800kbps results in an upstream margin around 4db which is not enough to maintain a connection during a phone call.

Latest stats here.

 

 

 

Superuser
Superuser
Posts: 10,324
Thanks: 1,847
Fixes: 19
Registered: 22-08-2007

Re: Unstable Connection

Hi Mikeh,

A warm welcome to the forums.  The problem you describe - loss of synch when the phone is used - is often caused by a faulty filter.  I recently had a friend change filters 3 times until we eliminated the issue.  Sometimes, it can also be the line splitter in the exchange.

What kind of filter are you using?

Do those dips in the SNRM plots coincide with making phone calls?  The sharp decay of SNRM and slower recovery seem  little odd to me.  There is some possibility of other in-house issues at play here.  Is your phone a DECT system?  How old is it?

What do you hear if you do a quite line test - dial 17070 option 2?

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

Hi townman

I have tried a few filters, 3 BT tail filters and one MK1 faceplate, so I thought I'd eliminated a filter problem. The dips in the in SNRM are phone calls incoming and outgoing, the last one is with a corded phone when I unplugged the dect phone . I have found sometimes there is a crackle at the start of a call which tends to go after a few seconds and the line becomes quiet. I have noticed the dip in SNRM just after the start of a call which recovers as the call continues. The quiet line test has had some noise very occasionally nothing definite.

The modem is connected to the master socket by a BT dsl cable and there are no other extensions.

 

 

Superuser
Superuser
Posts: 10,324
Thanks: 1,847
Fixes: 19
Registered: 22-08-2007

Re: Unstable Connection

Hi Mikeh,

Thank you for a comprehensive reply.  I would recommend raising an INTERMITTENT noisy line issue with your phone provider.  If the phone provider is not PlusNET, DO NOT mention the broadband issue, as the opine provider will try to duck taking ownership of the issue.

If it is PlusNET, use the link below.  Be sure to stress that the noise is intermittent and that it is present on a corded phone.

Note just to clarify, do you see the same SNRM spikes (shape and depth) when the DECT phone is disconnected and powered off?  (Power pack removed from the mains?)

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

Just had a call while I've been monitoring the line .This time the D/s margin has dropped at the beginning and at the end of the call. It recovers between the two actions. The U/s remains stable.

Superuser
Superuser
Posts: 10,324
Thanks: 1,847
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Registered: 22-08-2007

Re: Unstable Connection

There's quite a bit of jitter in that SNRM plot - is it the same during the day as well?  You might have a decaying switched mode power supply somewhere in the home causing the jitter.

The SNRM drop associated with the phone calls might be down to a faulty splitter card in the exchange - follow the phone line fault procedures.

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

This is a long line, 6kms from the exchange, so the line attn is very good for the length of line. It used to be only a 1mb and less connection until a BT engineer fixed a HR fault 5 years ago but there has always been a jittery SNM. I should say the line is rural and comes alone to our property for the last half mile and has to come over a rail crossing next to us.

I do have a fault reported last week and await their response.

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

I will do some better tests tomorrow with both phones to see any what differences show. Thanks for that

Superuser
Superuser
Posts: 10,324
Thanks: 1,847
Fixes: 19
Registered: 22-08-2007

Re: Unstable Connection

A rail crossing?  An electrified line?  WCML by chance?

mikeh
Rising Star
Posts: 50
Thanks: 6
Fixes: 1
Registered: 08-04-2016

Re: Unstable Connection

Not an electrified line, it has automatic barriers which may cause some interference? and some trains have a small effect on the error count but I have not found anything significant. The D/s SNRM tends to fall by 3db over the evening and  nightime,  so 9db should be a stable margin. Can the upstream margin be set a 9db instead of 6db?

I should also say that my line was upgraded to ASDL2+ in December from ASDL max. This is how my stats are at 10pm.

Stats recorded 17 Apr 2016 22:07:29

DSLAM/MSAN type: BDCM
Modem/router firmware: Not reported
DSL mode: G.992.5 Annex A
Status: Showtime
Uptime: 0 days, 14:55:35
Resyncs: 0 (since 17 Apr 2016 21:45:44)

Downstream Upstream
Line attenuation (dB): 55.5 26.5
Signal attenuation (dB): N/A N/A
Connection speed (kbps): 3840 643
SNR margin (dB): 6.4 6.1
Power (dBm): 19.2 12.4
Interleave depth: 32 0
INP: 1.22 2.61
G.INP: Not enabled

 

 

Community Veteran
Posts: 19,099
Thanks: 434
Fixes: 21
Registered: 31-08-2007

Re: Unstable Connection


mikeh wrote:
.........the connection dropped with an incoming phone call so I think there is some fault.

This and your other remarks about the weather and noise on the line, along with the SNRM graphs indicate a bad connection somewhere. It could be an intermittent High resistance joint or Intermittent Battery or Earth fault. It's unlikely to be an intermittent rectified loop unless you are finding incoming calls stop ringing but the caller is still on the line. You need to ensure this is handled as a phone fault by your line rental provider (Plusnet?) rather than a broadband fault. Really harp on about the intermittent noise on the line when using the phone. Make sure you make it quite clear that this started with the bad weather and all that detail is logged on the fault ticket, but particularly that it's intermittent noise.