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Why is a "degraded" line not a faulty line?

hadden
Grafter
Posts: 486
Thanks: 2
Registered: 27-07-2007

Why is a "degraded" line not a faulty line?

Until about 18 months ago my connection had a consistent 4mbps profile. Then it started to degrade over a few months until I had about a 3mbps profile.
I twice tried to get some assistance from Plusnet since the deterioration started, but that was not productive so I didn't dropped it both times, and got on with life. However, I have been trying again since 7/09/12 and my current profile for the past few weeks has been a steady 2.2mbps.
I won't bore you with the many various responses... but the latest words of wisdom are -
[quote= Plusnet person]I have tested the connection and the line is behaving as expected. Lines can degrade over time and this can effect lines.
The SNR margin will move and the target will change in line with the indicated line quality value.
Please monitor the connection and update us should any further issues occur.
So, as I understand it, Plusnet agree that my line speed has "degraded", and so I would expect that someone would would investigate this reduction in quality, determine the root cause and fix the problem.
Instead it seems that my problem can be made to go away simply by re-defining "degraded" to mean the same as OK.
Well, I have not given up, so my latest response on the ticket is:
[quote=me]
I agree with you - my line has badly degraded!
However, I am not expecting Plusnet to look at the fault and agree with me.
I am expecting Plusnet to correct the degradation.
Of course I will now be waiting the standard 48 hours until someone bothers to look at my ticket...
Thanks for listening.
142 REPLIES
CuBz
Grafter
Posts: 83
Registered: 12-11-2010

Re: Why is a "degraded" line not a faulty line?

I completely agree. I love Plusnet but one bad thing I can say about them is they don't try hard enough at times. When there is a problem with the line they just say it looks ok from their end and expect us to leave it at that.
Community Veteran
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Registered: 14-07-2009

Re: Why is a "degraded" line not a faulty line?

When your line underwent it's initial training period then a parameter called the "Maximum Stable Rate" was established, which is actually the lowest sync rate your line achieved (for any length of time) during that 10 days.  The Fault Threshold Rate (FTR) is then set at 70% of the Maximum Stable Rate.  If your sync rate is greater than the Fault Threshold Rate then Plusnet will have a very hard  time persuading BT Openreach to do investigate.  So the literal answer to your question is that a "degraded" line is not a faulty line if it still syncs above its Fault Threshold Rate. Plusnet can tell you what your FTR is.
hadden
Grafter
Posts: 486
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Registered: 27-07-2007

Re: Why is a "degraded" line not a faulty line?

Thanks, but I have tried the "Fault Threshold Rate" approach  Sad
Last year when I complained about my profile dropping to 3000 kbps, my sync speed was about 3400kbps (from memory) and my FTR was about 3300 kbps. So, I was told that there was "no fault". At the time I reckoned that the FTR was unrealistically low, but I had to accept the "rule".

This time, on 10/09/12 I was told that my MSR 6816 and FTR was 5452 kbps. That was a pleasant surprise as it was even higher than before the deterioration started.
However by 28/09/12 I was told this:
[quote=Plusnet person]Upstream DSL Link Information Downstream DSL Link Information
Loop Loss: 29.0 49.5
SNR Margin: 6 12
Errored Seconds: 0 6
HEC Errors: 0
Cell Count: 2718317 72571893
Speed: 859 2674

Maximum Stable Rate (KBPS): 6816 Fault Threshold Rate (KBPS): 5452
Mean Time Between Retrains (Seconds): 86400 Mean Time Between Errors Upstream (Seconds): 86400
Indicative Line Quality: A Mean Time Between Errors Downstream (Seconds): 133

Tags: 2.5Mbps; typically the line speed would range between 1Mbps and 4Mbps.
Summary: Radius shows a stable connection with minimal drops. Sync rate is below FTR making this LTB however based on the loop loss the FTR is totally incorrect.
So, as the FTR no longer had credibility, I wasn't allowed to refer to it.
By 17/10/12, and only because I requested it, the MSR was recalculated as 2272 and the related FTR was stated as 1817 kbps.
Assuming that the MSR is accurate this time, this is part of basis for saying that the capability of my line is now degraded far below what it was actually operating at 18 months ago.
Community Veteran
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Registered: 10-04-2007

Re: Why is a "degraded" line not a faulty line?

Pity we can't degrade our payments to Plusnet in proportion to the degradation of the line!
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 4,833
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Registered: 14-07-2009

Re: Why is a "degraded" line not a faulty line?

If the line was retrained the FTR will have been reset.  But if that has not happened maybe there is some old fault ticket where the old (true?) FTR of about 3300kbps is documented?
Community Veteran
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Re: Why is a "degraded" line not a faulty line?

http://www.kitz.co.uk/adsl/max_speed_calc.php says your line is performing way below where it should be.
What does http://www.dslchecker.bt.com/adsl/adslchecker.welcome say for your line?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
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Registered: 31-08-2007

Re: Why is a "degraded" line not a faulty line?

According to the kitz calculator a bog standard (ie not especially good) line should achieve 5568 sync speed. most good lines will achieve at least 1Mbps higher, so an MSR of 6816 is perfectly feasible and reasonable, especially if all neighbouring lines are balanced and have no faults, the interference will be minimal.
Who the hell is this agent that is starting to invent his own rules, it's bad enough having to put up with BTw's carp that you can drive a bus through! I really think this is totally unacceptable. Even if you took the typical expected value the FTR would be around 3900, which your sync speed is below
JohnJ you should never have asked for a line reset with that sync speed, you will have to have virtually complete failure of your line to get a fault raised with that current FTR. It will also be interesting to see what the linechecker that jelv has linked gives for your line, because I'd like to know where this lot came from -
"Tags: 2.5Mbps; typically the line speed would range between 1Mbps and 4Mbps".
Put a reply on your ticket asking to see the full Openreach Data for your line, it will include things like -
Circuit line length estimate:
Circuit line length calculated:
DP Line length estimate:
Celerity line loss:
LLC Line loss:
Can you post your current modem/router stats John? I presume you've tried a filter swap, have you checked performance with another modem/router?
hadden
Grafter
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Registered: 27-07-2007

Re: Why is a "degraded" line not a faulty line?

Quote from: ReedRichards
If the line was retrained the FTR will have been reset.  But if that has not happened maybe there is some old fault ticket where the old (true?) FTR of about 3300kbps is documented?

Do you mean like this one from 05/09/11. This was during my first attempt at getting the problem fixed.
(sorry I mis-remembered the FTR as 3400 when it was actually 3635.)
[quote=ticket#45367149]    Upstream DSL Link Information Downstream DSL Link Information
Loop Loss: 29 47.5
SNR Margin: 23.5 10
Errored Seconds: 1 0
HEC Errors: 0 0
Cell Count: 11459099 189980478
Speed: 448 3488

Maximum Stable Rate (KBPS): 4544 Fault Threshold Rate (KBPS): 3635
Mean Time Between Retrains (Seconds): 86380 Mean Time Between Errors Upstream (Seconds): 3599
Indicative Line Quality: R Mean Time Between Errors Downstream (Seconds): 15
hadden
Grafter
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Registered: 27-07-2007

Re: Why is a "degraded" line not a faulty line?

@ jelv
Kitz estimate based upon attenuation... yup, but I had been at the speed estimated there 18 months ago. I have years of routerstats data and copies of BT SpeedTester results.
adslchecker currently says:
[quote=BT]Our test also indicates that your line currently supports an estimated ADSL Max broadband line speed of 2Mbps; typically the line speed would range between 1Mbps and 3.5Mbps.
Our test also indicates that your line should be able to have an ADSL2+ broadband service that provides a fixed line speed up to 2Mbps.
Our test also indicates that your line currently supports an estimated ADSL2+ broadband line speed of 2.5Mbps; typically the line speed would range between 1Mbps and 4Mbps.
18 months ago I was on ADSL1 (at my request) on a 21CN exchange. Then, in August this year,  I was switched over to ADSL2 and a few weeks ago I requested to be moved back to ADSL1 again, but was put on the pseudo ADSL option. Therefore I am not sure if the ADSLMax estimate above is supposed to be more applicable.
The adslchecker estimates used to be much higher, when my actual line speed was much higher, though never quite as high as my actual speed. My understanding is that BT crowd source the data from the recent history of my connection and perhaps a few others around it. That data is be averaged. So, if I had a reasonable connection speed and my few neighbours had dodgy connections, the "estimate" would always be below my actual.
hadden
Grafter
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Registered: 27-07-2007

Re: Why is a "degraded" line not a faulty line?

@ Anotherone
I have lots of data and will extract what you ask for.
I'm sorry I asked for the line reset, but as PN wouldn't accept the existing FTR as valid.

full Openreach Data - This data has been provided twice in my ticket, I only copied the part above to show the FTR.
Here is the extract from the two occasions:
[quote=17 Oct 2012]Upstream DSL Link Information Downstream DSL Link Information
Loop Loss: 28.8 49.0
SNR Margin: 6 4
Errored Seconds: 0 16
HEC Errors: 0
Cell Count: 9222 10759
Speed: 872 4307

Maximum Stable Rate (KBPS): 6816 Fault Threshold Rate (KBPS): 5452
DLM Data:WBC 160K - 24M Medium delay (INP 1) 6dB Downstream, UC Medium delay (INP 2) 6dB Upstream (ADSL2+) Interleaving:I ILQ: A
MTBE D/S 16 U/S 86400 MTBR 86400 UPTIME 50400
Ellacoya: Service_Offer_11
CLT: DT
Circuit line length estimate: 4001
Circuit line length calculated: 4280
DP Line length estimate: 3956
Celerity line loss: 53.9
LLC Line loss: 56.73
TAM: DNR
RADIUS: Generic Speed 3600 No Time Out

[quote=5 Nov 2012]
Upstream DSL Link Information Downstream DSL Link Information
Loop Loss: 26.7 48.0
SNR Margin: 10.5 13.0
Errored Seconds: 0 1
HEC Errors: 0
Cell Count: 583 583
Speed: 704 2816

Maximum Stable Rate (KBPS): 2272 Fault Threshold Rate (KBPS): 1817
DLM Data:BT WBC 8M/Uncapped/12dB/Interleaved (ADSL) Interleaving:I ILQ: A
MTBE D/S 32 U/S 23385 MTBR 23385 UPTIME 70156
PTTR: DATE: 30-10-2012 07:47:17 - OOD
Ellacoya: Service_Offer_11
CLT:
Celerity line loss: 53.6
LLC Line loss: 56.73
Circuit line length estimate: 4001
Circuit line length calculated: 4280
DP Line length estimate: 3956
TAGs:
Speed: 2500
Min: 1000
Max: 4000
RADIUS: Generic Speed 2200 No Time Out
I've attached the current ADSL Status page from my Billion 7800N.
I last tried filter swaps before the start of the current ticket in September.
I also tried a BT 2700HGV in September. That was the router I was using from a few months before the problem started 18 months ago until earlier this year.
I purchased the Billion 7800N earlier this year as I could at least tweak the target SNR to try and maintain some speed, which I couldn't do with the 2700HGV.
FYI I have several years of RouterStats data.
Community Veteran
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Re: Why is a "degraded" line not a faulty line?

Hi John,
to me, there are a number of indicators that show you have an extremely good quality line, although of course there is the possibility of some fault being present at the moment.
Looking at your Loop loss, the Celerity figure is better than the LLC figure (although I don't know when it was calculated) and your actual loop loss, both from Plusnet line tests and your modem/router stats is somewhat better than those and the typical predicted values. The agent that said "Summary: Radius shows a stable connection with minimal drops. Sync rate is below FTR making this LTB however based on the loop loss the FTR is totally incorrect" clearly has no engineering background of any worth and seems to think all lines are the same.
The data also shows "Indicative Line Quality:   A   Mean Time Between Errors Downstream (Seconds):   133"  more clear evidence of some degradation, as at some previous point, Indicative Line Quality would have been G (green).
Although I note one report above - Indicative Line Quality R (red),  I assume that's recent.
That all said, whilst the platitude that you were given (quoted in your OP) is obviously truthful, what is not acceptable, is that Plusnet seem to have made no attempt to either find out why this degradation has occurred or assist you in doing so, nor push a LTB fault to BTw (the latter possibly a bit trickier now). What is good John is that you have a documented history of how well your line has performed previously (as have I for my line) and an extremely reasonable expectation that it should be sorted and that previous performance (or near) recovered.
So down to the nitty griitty. Whilst you have obviously mentioned the headline problem about the drop in speed, the cause of this is because your Target SNRM has risen (looks as though it could be 12dB) and comparing various previous figures it suggests a lot of noise/interference is present as well. The question we need to try and answer is why.
I'm not going to mention filters or modem/routers again as you've obviously got a couple of quality well respected boxes there giving comparable results, the only thing I would say is don't swap things around when doing certain checks because you don't want to compare chalk with cheese. Also, at the points where you want/need to swap things about or investigate wiring etc, I advise drop your PPP session, pause, then power it down and wait a minute before unplugging from the line (or what ever else) and take a least 10 minutes before connecting and powering up again so that DRM doesn't interpret your action as connection drops, also no more than 5 of these in an hour, then I'd be inclined to leave it alone for the rest of the day.
I expect you may have been through some of this yourself (or possibly with advise from Plusnet - or not), but as it hasn't yet been mentioned I need to ask.
Down to basics - do you have/or had any crackling or other audible noise on your line when using the phone, or any other problems with incoming or outgoing calls? Who do you pay line rental to?
I assume all your Microfilters that look like this and you have an NTE5a Master Socket as on the LHS of the picture. Do you have any hard-wired extension sockets, how many, how old, what type of wiring is it, how new/old, is the bell wire connected ?
Have you checked your ADSL stats from the test socket?
I think that's enough to be going on with, sorry if it's boring stuff you've been through before.
hadden
Grafter
Posts: 486
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Registered: 27-07-2007

Re: Why is a "degraded" line not a faulty line?

Hi
Thanks for your time on this.
I don't want to give the impression that nothing has happened at all, since 7 September. But, apart from one CS person initially, the rest has been based upon maintaining the current poor quality and not trying to restore the previous quality. I would post the details of the responses, but it may take a while to censor out the identifications. Would you mind me sending a PM with the ticket content?
To answer your questions:
1. No crackling on line, no other problems. I've just carried out another quiet line test again, to check.
2. Line rental = Plusnet
3. All microfilters are sockets on a flying lead. Current one is a BT 03478 (NA30513)
4. Master socket is NTE5 with a BT logo.
5. I have no hard wired extensions. I had one until earlier this year because my router had to be located at a different room from my master socket (it was near to the ceiling at the front door). However, I then ran power to beside the master socket, relocated my router there and removed the hard wired extension wiring from the master socket, as per picture below. The former extension wiring now plugs into the phone socket on the ADSL filter. I had disconnected the bell wire several years ago.
6. I have been connected to the test socket since 07/09/12, so all stats since then have been on that basis.
Quote from: Anotherone
...sorry if it's boring stuff you've been through before.

Unfortunately I have a lot of patience and an open engineering mind, so I appreciate that repeating actions is sometimes necessary. Smiley
Rich
Grafter
Posts: 184
Registered: 30-07-2007

Re: Why is a "degraded" line not a faulty line?

I notice that the router is very close to its PSU.  These can sometimes cause a lot of interference, so it might be worth moving the router as far away as possible.
Richard.
RichardB
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Re: Why is a "degraded" line not a faulty line?


And also very close to a home plug.
Could be worth checking the ADSL performance with the Home plug turned off.