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Please could someone help me interpret a Routerstat graph?

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Grafter
Posts: 30
Registered: ‎10-12-2007

Please could someone help me interpret a Routerstat graph?

Hi all,
I've been having an ongoing issue with connectivity and speed over the last year and have just started running Routerstat to help me track things. I've had the program running all today and it's been fairly static, a downstream sync speed of around 1500kbps and a noise margin of around 14.5db.
About an hour ago  I noticed the router light (netgear DGN2000 with latest firmware) had gone red, so I then checked the graphs.
The noise margin graph showed a slide down to 8db and then shortly after that a further fall to 1db before increasing slightly to about 3db. Please see attached jpg file. Sync remained solid at around 1500kbps.
With the margin so low I could not get any throughput at all on the connection, so was forced to reboot the router.
On the reboot the noise margin jumped back to 14.5db as you can see on the graph but the downstream sync speed is now only 600kpbs.
Nothing changed in the house during this time, so I'm baffled what could be causing this. Router is six months old and I'm using a brand new ADSLnation microfilter at the mastersocket, with no extensions present.
After the reboot I ran a BT speed test and got the following:
Download speedachieved during the test was - 537 Kbps
For your connection, the acceptable range of speeds is 400-2000 Kbps.
Additional Information:
Your DSL Connection Rate :656 Kbps(DOWN-STREAM), 692 Kbps(UP-STREAM)
IP Profile for your line is - 1250 Kbps
The router is showing the following now (noise margin is now nearly 5db higher than when I initially rebooted!):
     
      ADSL Link     Downstream     Upstream    
      Connection Speed       657 kbps       695 kbps  
      Line Attenuation       64.5 db       35.3 db  
      Noise Margin       19.8 db       6.9 db    
BT came out over a week ago and diagnosed an issue with some exchange hardware (which they then switched out) and advised me that nothing appeared to be wrong my end.
Does anyone have any ideas what could be causing the changes in noise margin the graph is showing? A noise margin swing of 20db within an hour can't be normal!
Thanks and best regardss
Simon
   
12 REPLIES 12
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Community Veteran
Posts: 38,460
Thanks: 1,033
Fixes: 62
Registered: ‎15-06-2007

Re: Please could someone help me interpret a Routerstat graph?

Simon,
can you plug the router into the test socket and report the stats with nothing else connected at all
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Grafter
Posts: 30
Registered: ‎10-12-2007

Re: Please could someone help me interpret a Routerstat graph?

Thanks for the response Jim,
I'll set this up when I get home later and will run Routerstat again overnight. I've run from the test socket in the past and never saw a change in the behavior of the line, although without some monitoring software I may have missed something.
When BT came last year they fitted a new front plate at the master socket, which I believe included a built in bellwire filter. There are no extensions in the house and I've currently got the Sky+HD box unplugged, so beyond a telephone there is nothing else connected. I purchased a new corded phone within the last month to see if my cordless DECT phones were causing interference and this made no difference either. (I'm still using the corded phone).
I'll post the results later from the test socket and without the phone plugged into the microfilter.
Thanks again for your advice and best regards
Simon
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Grafter
Posts: 21,036
Thanks: 2
Registered: ‎04-04-2007

Re:Please could someone help me interpret a Routerstat graph?

Hi Simon,
To be honest with you, I was expecting to see a banded profile causing the high noise margin, but there isn't one on your line currently.
However, it's possible that there was and it has now been removed.  I take it that the problems are ongoing?
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Grafter
Posts: 30
Registered: ‎10-12-2007

Re: Please could someone help me interpret a Routerstat graph?

Hi James,
Yes the problems are ongoing. After last night's blip I ran Routerstat through the night and it maintained a solid 600kbps connection at about 20db downstream noise margin. I rebooted the router at about 7.30am this morning and it synced at 1500kbps and a margin of 15db.
I popped home at lunch and the router was still connected at 1500kbps and 15db and was showing as having a solid connection for 7 hours, since the morning reboot. I won't keep my PC switched on when I'm not home so Routerstat hasn't been running through today.
I used to have a solid 2000kbps connection and I think the noise margin was much lower. After the exchange hardware was changed on the 23rd October I've had a lot more variability in the sync speed and noise margin. Straight after the switch out of the kit it was 2500kbps and 3db and has been moving around ever since. Profile was stuck on 250kbps for about 5 days but now appears to be 500kbps. It's a move in the right direction but still loads lower than I used to get.
I'll plug into the test socket tonight and will post the results later tonight.
Thanks again for your help.
Best regards
Simon
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Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re:Please could someone help me interpret a Routerstat graph?

Hi Simon,
I hope that does help things along, looks like the next stage of the fault is another appointment so we'll either have an improvement or some more information for the engineer to help his investigation.
My fingers are crossed for you.
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Grafter
Posts: 30
Registered: ‎10-12-2007

Re: Please could someone help me interpret a Routerstat graph?

Thanks for all your input. I'm now home and have plugged into the test socket and unplugged my phone; so my microfilter and router are now the only pieces of kit connected.
The results are:
ADSL Link Downstream Upstream
Connection Speed 1507 kbps 695 kbps
Line Attenuation 64.5 db 35.3 db
Noise Margin 15.3 db 6.3 db
This looks like there is no significant difference between being plugged into the test socket or master socket. I've got Routerstats running again as well, so will see if there are any odd results in terms of the noise margin or loss of connectivity tonight!
Thanks again for all your help.
Best regards
Simon
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Grafter
Posts: 30
Registered: ‎10-12-2007

Re: Please could someone help me interpret a Routerstat graph?

OK I'm loving this Routerstat tool! I've just run a couple of tests, attached are the results on the noise margin.
Over the last couple of months I noticed that whenever I received an incoming call on my home phone the ADSL connection was lost on the majority of occassions.
I've purchased about 6 microfilters in the last year to test whether my problems were down to dodgy filters. Last month I purchased a batch of three ADSLNation filters, so I'd have one spare to play with and then a brand new sealed one to use if the BT engineer ever told me it was a filter problem!
Tonight I've got the microfilter plugged directly into the test socket and then just the router. No phone or Sky+HD box. I left the connection running for one hour when I came in to see how stable it was, it held 1500kbps and a noise margin of 15db.
I then called the house from my mobile (with no phone plugged in) and left myself a message on BT 1571. About 20 seconds into the message the noise margin on Routerstat droped to zero and the router lost sync!
The connection came back again almost immediately and returned to 1500kbps and 15db. I left it half an hour to test the stability of the connection and then decided to switch the microfilter for one of the spares and repeat the test.
Exactly the same thing happens! Can BT not see this type of thing with their remote diagnostic tools? The BT engineer told me he suspected an HR fault and told me later he'd traced the fault back to faulty kit at the exchange. Does this suggest there is further faulty kit between the mastersocket and the exchange or could it still be something my end?
Appreciate all your advice.
Best regards
Simon
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Grafter
Posts: 21,036
Thanks: 2
Registered: ‎04-04-2007

Re: Please could someone help me interpret a Routerstat graph?

Simon,
Just a quick one - do you hear any noise on your voice line when picking up the telephone?
Or is there no obvious nose, but the ADSL just drops when you get an incoming call?
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Grafter
Posts: 30
Registered: ‎10-12-2007

Re: Please could someone help me interpret a Routerstat graph?

Hi James,
Thanks for the quick reply. There is no noticable noise on the voice line. When I was using the DECT cordless phones there did appear to be a bit of a hiss and echo but this has completely gone since I switched over to a corded phone again.
Best regards
Simon
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Grafter
Posts: 21,036
Thanks: 2
Registered: ‎04-04-2007

Re: Please could someone help me interpret a Routerstat graph?

Thanks Simon.
If you give me a shout tomorrow I'll check to see if BT are after appointment times.
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Community Veteran
Posts: 3,789
Thanks: 1
Registered: ‎08-06-2007

Re: Please could someone help me interpret a Routerstat graph?

Sounds like a classic BT fault to be honest.
Explain to the Engineer what happens, and demonstrate it if possible.
He'll generally make the excuse that he needs to go down the line/to the exchange at some point.  Ask him to return to retest after making any modifications, or at least call you so that you can retest for him.  I suspect he won't, but it's always worth a try !
B.
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Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Please could someone help me interpret a Routerstat graph?

Hi Simon,
BT are indeed after engineer times, if you can pop your available times on the ticket and drop me a PM I'll get that chased and booked for you.