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[NewtronStar]

My VDSL2 circuit has been doing well for a year or so and it was that stable I even turned off DSLstats but since the end of December its hard to hold onto a sync that lasts more than 48 hours.

No noise on the phone line, Errored seconds are fine SNRM looks good for G.INP the only thing that sticks out in the graphs is the LEFTRS have never seen some much activity in this graph before.

I'll upload this graph and see what members think if my memory serves me right I was only seeing 8 LEFTRS in 24 hours 6 months ago.

[burakkucat]

There is definitely something odd happening but I am not the one able to diagnose a problem with a VDSL2 (ITU-T G.993.2) circuit.

I presume the Hlog and QLN plots are acceptable? (There's no need to post copies; I just would like confirmation that the physical metallic pathway has not developed a significant error.)

[NewtronStar]

The Hlog and QLN has not changed at all BC and nothing new or old in the house is causing this that I can correlate at those times.

[burakkucat]

That's good to know.

Perhaps j0hn will have a few ideas, tomorrow.

[Chrysalis]

I have never really studied these part of stats before and with the demise of MDWS we dont have other lines to compare to now.

Do FEC and CRC look normal during these busy periods?

[renluop]

Just peeping in! 
From http://forums.thinkbroadband.com/fibre/4532420-what-are-g-leftrs.html?vc=1 it seems they are re transmitted CRCs

[NewtronStar]

Hi Chrysalis the CRC count looks ok with 8 or 9 peaks per day the FEC counts are mostly around 28000 per min after XdB kicked in last year, i'll give you the error counts.

Code: [Select]

Previous 1 day time = 24 hours 0 sec
FEC:            24026932                87
CRC:            1163            38
ES:             35              18
SES:            19              0
UAS:            37              18
LOS:            1               0
LOF:            6               0
LOM:            11              0
Since Link time = 19 hours 58 min 15 sec
FEC:            15578198                38
CRC:            35              19
ES:             8               14
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
 >

[tubaman]

A quick 'google' found this discussion on LEFTRS - http://forums.thinkbroadband.com/fibre/4532420-what-are-g-leftrs.html?fpart=all&vc=1 (which references back to Kitz LEFTRS definition of course ).
Assuming that is correct then you have developed a noise issue on the line that even G.INP is struggling to deal with.
 

[NewtronStar]

Cheers Renluop & Tubaman for the link an interesting read kind of sums up what is going on with this line increased noise from where I haven't a clue, If the DLM could switch me over to Re-Tx high i wonder if that would help stop those drop outs but since capping the DS sync last year to get Re-Tx low it seems this circuit has become stuck.

[ejs]

The sync looks capped - if it is, perhaps uncap it and let the DLM do its thing.

I thought the idea of capping the sync to get re-tx low had a final step of uncapping the sync once on re-tx low.

[NewtronStar]

EJS Manual sync capping was removed 2 days after this circuit went Re-Tx low 4-5 months ago.

Code: [Select]

adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    4
Last initialization procedure status:   0
Max:    Upstream rate = 6001 Kbps, Downstream rate = 44641 Kbps
Bearer: 0, Upstream rate = 6001 Kbps, Downstream rate = 40000 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17a
TPS-TC:                 PTM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        4.7             6.2
Attn(dB):        24.8            0.0
Pwr(dBm):        11.2           -0.9

                       Bearer 0
INP:            45.00           0.00
INPRein:        0.00            0.00
delay:          0               0
PER:            0.00            9.57
OR:             0.01            26.73
AgR:            40252.99        6027.85

                        Bearer 1
INP:            2.50            0.00
INPRein:        2.50            0.00
delay:          0               0
PER:            16.06           0.01
OR:             47.81           0.01
AgR:            47.81   0.01














[burakkucat]

I wonder if powering off the CPE and physically disconnecting it from the line, overnight, might have a beneficial effect? 

[PhilipD]

Hi

This is the sort of thing I've found with VDSL in two properties.  In the latest home, I've gone 100+ days of VDSL staying sync'd without dropping, had a long stretch of something like 180 days then the internet stopped (sync'd remained up) so I rebooted the modem so interrupting that long stretch, it was still sync'd but not passing any traffic and turned out to be an issue with the ISP and resolved after about 30 minutes.  Had another outage about 100 days later for 10 minutes or so and was so confident it wasn't my end didn't reboot anything and it was up working again after 20 minutes or so.  It was very stable.

Then over the last several weeks had two occasions where sync has dropped out completely, one time for an hour, and now I can't remain sync'd up for more than a couple of weeks (often less) before it drops and re-sync's usually overnight but sometimes in the day.  All stats look the same, SNR a little lower at 8.1 from 8.7, no DLM intervention on my line, its non-interleaved, no G.INP here as its ECI.  This lower reliability has coincided with a second VDSL cabinet being installed. During the installation work which I saw going on, the line didn't flinch, but since then it's just not had the same stability.  Possibly the effect of new customers coming on line and changing noise levels causing the line to want to resync, but each time the SNR hasn't changed before or after., although waiting for a bad cross-talker to appear now.  No noise on the telephone line.

The same happened at a previous property, started out brilliant for the first year or so, then would never stay connected more than a week or less before it decided it needed to re-sync.

Re-syncing overnight isn't that bad, but when its random during the day and I'm working from home and suddenly get cut off from a Remote Desktop Session or video call, it's annoying and doesn't look good.

It's the technology, it is just so fickle.

Regards

Phil