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[adslmax]

Hi everyones

Do you think there is possible chance of DLM has a problem with system stuck with a banding profile at openreach system. I do believed it does. Need to raise this with isp's to chase this up with Openreach because the downstream still banding at 74Meg capped wouldn't go back to 80Meg as the result of losing 6Meg off:

1st resync: 11th Nov 2017

Downstream   Upstream
Line attenuation (dB):     11.5      0.0
Signal attenuation (dB):   Not available on VDSL2      
Connection speed (kbps):   79999      20000
SNR margin (dB):           8.3      13.9
Power (dBm):               12.4      -0.6
Interleave depth:          8      8
INP:                       46.00      47.00
G.INP:                     Enabled      Enabled

2nd resync: 12th Nov 2017

Downstream   Upstream
Line attenuation (dB):     11.5      0.0
Signal attenuation (dB):   Not available on VDSL2      
Connection speed (kbps):   73998      20000
SNR margin (dB):           10.1      14.0
Power (dBm):               12.5      -0.6
Interleave depth:          8      4
INP:                       52.00      55.00
G.INP:                     Enabled      Enabled

3rd resync: 22nd Nov 2017

Downstream   Upstream
Line attenuation (dB):     11.5      0.0
Signal attenuation (dB):   Not available on VDSL2      
Connection speed (kbps):   74000      20000
SNR margin (dB):           10.0      14.4
Power (dBm):               12.4      -0.6
Interleave depth:          16      8
INP:                       49.00      47.00
G.INP:                     Enabled      Enabled

4th resync: 26th Nov 2017

Downstream   Upstream
Line attenuation (dB):     11.4      0.0
Signal attenuation (dB):   Not available on VDSL2      
Connection speed (kbps):   74000      19999
SNR margin (dB):           9.9      15.1
Power (dBm):               12.5      -0.9
Interleave depth:          16      1
INP:                       49.00      0
G.INP:                     Enabled      Not enabled

[kitz]

Max...  a few of us have been discussing this for years on here and how long it takes to get banding removed. 

But on the other hand... look at it this way.   
A couple of weeks ago the DLM monitored your line doing 80 resyncs in one day.    To DLM that is an extremely unstable line, so it did the right thing.
It's now going to need convincing that your line is stable before removing any banding.

We've told you on numerous occasions that it could take several weeks/months..  and that because your line still falls within acceptable levels then you won't qualify for a reset.

I meant to type this in your thread over on the PN forums but never got around to going over there...   but since I still had your GEA test results in notepad then I may as well post it here.

-------------------

Code: [Select]

Interference Pattern Regular Interference Observed Daily
Interference seen on 2-3 days out of the recent 7

Code: [Select]

Service Impact Retrains Observed
Self explanatory

Code: [Select]

Retrains 0.0 80.0 0.0
That is exceedingly high.  Usually it is only 1or2 unless the line is flapping around.
I think this is also over the past 7 day period, and if Im right then...
The min no of retrains in any one day over the past 7 days is 0
The max no of retrains in any one day over the past 7 days is 80
Not sure how the average is worked out.  If they are using median or mode average (as opposed to mean) then it would be 0



----
ETA - Just for the sake of clarification...  these results are based on a GEA test run on the 13/11/2017

[kitz]

Rather than GEA tests this is what I'd like to see

link

@Gandalf

Can you by any chance get the ILQ counter status?
That would be interesting to see.

I'm not sure if Plusnet can get ILQ counter status on NGA, but they can for 21CN.

[adslmax]

@ kitz

Code: [Select]

Retrains 0.0 80.0 0.0 I blamed this on power cut or engineer working on my cabinet at that time. Impossible for me to reboot modem or swap modem in 80 times in a day! No way!

[gt94sss2]

Do you think there is possible chance of DLM has a problem with system stuck with a banding profile at openreach system. I do believed it does.

No, it doesn't.  DLM is working as attended - each resync is gradually reducing the level of INP on the line in small steps to ensure the line remains stable after each change. It does this first and will then eventually look at changing the speed.

What would be more interesting would be knowing the time between each DLM resync.

[kitz]

Because you had the HubOne and and no line monitoring we will never know for certain... although I suspect you may be right about the power problem could have had something to do with it. 

Regular Interference Observed Daily

This bit also infers that your SNRm was unstable & you'd been getting errors.   Regular = 2 or 3 days out of the past 7.

Power problems could have caused your SNRm to start spiking all over the show...  or it may have just been oscillating a fair bit between several dB.   
It's not unusual for any modem to get oscillating SNRm after power failures or power cuts.
Whatever it was..  DLM detected that you SNRm was showing some sort of interference and swinging around generating lots of errors.

[kitz]

What would be more interesting would be knowing the time between each DLM resync.

I don't think we have any way of knowing that     It could have been over the course of the day..  or it could have been within an hour :/

If Plusnet can get ILQ counters then it may give a bit more info.

[ejs]

I think the "Regular Interference Observed Daily" doesn't really imply very much. Supposedly this regularly observed daily interference is causing retrains, yet all the retrains observed appear to be a one-off event on a single day. If this regularly observed daily interference were really causing retrains, I'd expected there to be daily retrains, which aren't happening.

I assume the interference is actually detected from the INM (impulse noise monitoring) data rather than a graph of SNRM.

I've seen enough GEA Test results posted showing "Regular Interference Observed Daily" that it doesn't really seem to matter. Lots of lines will have some detectable interference.

[kitz]

I assume the interference is actually detected from the INM (impulse noise monitoring) data rather than a graph of SNRM.

My assumption that the SNRm would be oscillating...  which was in turn responsible for generated errors.

You are correct that there is no SNRM graph (well afaik there isnt)...  but rather INM based on the number of errors recorded.

I've seen enough GEA Test results posted showing "Regular Interference Observed Daily" that it doesn't really seem to matter. Lots of lines will have some detectable interference.

That 2-3 day figure came from something I read long ago as to what BT defined as regular within KBD results.  It may have changed since..   I dunno.   

[kitz]

You are correct that there is no SNRM graph (well afaik there isnt)

Actually I have a niggle about this...  because I cant remember now and its stuff I saw long ago.   But something is really bugging me on this..  that there was something within BRAT that may have the ability to do some very basic graphing.  Do not ever quote me on that though as its really hazy from when the Brandenburg tool first came out. 

That doesnt change the fact that analysis is done based on the error data.    The graphing was supposed to be a nice extra for SPs.   

[kitz]

Woah...  here you go...  I thought I remembered something.  This was written in 2014 when my memory was a hell of a lot better than it is now :/

~ Knowledge Based Diagnostics - KBD

The data collector also records other stats about the line health which is used for fault diagnostics.

This system is known as KBD or Knowledge Based Diagnostics and whilst not part of the DLM process itself, it allows an ISP to view line data in depth and will show not only the MTBE & MTBR but other information such as SNR Margin, attenuation, power and error counters. This information is stored in an RRT database.

   
BT KBD RRT
Data collected for KBD can be graphed and viewed using the RRT (Reactive Repair Tool).
The BRAT tool (Brandenburg Rapid Analysis Tool) can use this data to help identify and spot faults such as those indicative of REIN.

[adslmax]

@ kitz I do remember now, it blamed over hub one updated software version and the line couldn't reconnection from dslam flashing on off for couples of minutes and hub one keep rebooted it.

Code: [Select]

Total time = 3 days 2 hours 55 min 28 sec
FEC:            6508            1604
CRC:            569             7
ES:             11              4
SES:            11              0
UAS:            64              53
LOS:            1               0
LOF:            7               0
LOM:            0               0
My SNRM was between 9.9 and 10.9 over 3 days on the downstream.

[adslmax]

What would be more interesting would be knowing the time between each DLM resync.

Done, I have re-edited time stamp on the first post.

[kitz]

@ kitz I do remember now, it blamed over hub one updated software version and the line couldn't reconnection from dslam flashing on off for couples of minutes and hub one keep rebooted it.

Code: [Select]

Total time = 3 days 2 hours 55 min 28 sec
FEC:            6508            1604
CRC:            569             7
ES:             11              4
SES:            11              0
UAS:            64              53
LOS:            1               0
LOF:            7               0
LOM:            0               0
My SNRM was between 9.9 and 10.9 over 3 days on the downstream.

Just to be clear arent those from the Billion?...   and after DLM had started to take action on your line.   From memory it had already applied INP (and Interleave depth 8).
It sounds like the damage was already done whilst the HubOne was on the line and you had no access to line stats.

[adslmax]

Those stats are from billions modem as I put hub one as the wireless only