Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[burakkucat]

. . . Could it point to suspect joints in the PCP?

To me, yes, it does.

[kitz]

If having the PCP innards open to the weather affected many lines, you'd expect that a "wide-area event" would be triggered, and the ESs ignored.

I doubt my high error rate was anything to do with it, it happens often enough without any other cause that I know of. Its been happening every 8 days for the past few weeks and been going on for too long.  Although saying that it also entered into a spell of high errors when the DLM struck so no definite pattern.     Connection currently feels very laggy at times more so than I'd expect from interleaving, but the E/S seem ok now that INP has been applied.

I just mentioned the PCP casing replaced as a PS as I was curious what they are doing.   It appears that the cab across the road is also getting a new shell too. 

[NewtronStar]

Kitz it will turn out to be a fault on the D-SIDE anywhere from PCP cabinet to your UG feed under the driveway, I just wish we could start the ball rolling by replacing the UG feed 1st and then see how your line performs.
 

[burakkucat]

. . . I just wish we could start the ball rolling by replacing the UG feed 1st and then see how your line performs.

If only Black Sheep could park his van on Kitz' drive, one afternoon and Walter's Wheelbarrow trundles its way to Blackpool, collecting me from Bury St Edmunds as it passes.

With all the equipment thus available, we could soon get that UG service feed replaced . . . 

[kitz]

I just wish we could start the ball rolling by replacing the UG feed 1st and then see how your line performs.

Unfortunately all hopes of that has now failed.  Line is now performing less than BTw estimates, but since whatever the OR guy did the other week, PN now say they cant re-raise it as a fault because Im currently syncing higher than this new figure MGAL of 62Mbps.   As I said earlier I think I was a bit fobbed off with "monitor for 30 days".  I did not know at that time, that my reportable figure would drop from 68 to 62Mbps. 

The thing is what happens if I do manage to get Openreach out again and then what happens if it behaves like it did for several days last week where the SNR never budged.
Then I have things a couple of days last week where its throwing 10's of 1000's of errors and trying to do anything is impossible.... or it could be like it is right now and oscillating by 1dB which could be seen as within normal parameters.    You and I know that the regular pulsing of 1dB as seen on MDWS isnt right, but would OR treat it like a perfectly normal 1dB swing that we could expect to see on any line over the course of the day.   Swings are OK, pulsing isnt so good.

I really, really do have a lot on right now and Im not on top form which is why I haven't taken it further.  I do feel that with hindsight I was fobbed off by the engineer because I had no idea that my min reporting figure would drop.  This line Im on now is no better than the one I was on last month.   In fact its worse - at least when I was going through a good patch I could sync at 75Mbps.   This one wont sync higher than 72Mbps.

ETA
Attaching MDWS graph showing SNRm over past 10 days showing that upstream has taken a bit of a hammering too.

[kitz]

If only Black Sheep could park his van on Kitz' drive

If BS had a 444B with him that would be great.   The symptoms look very REIN like in some respects, but Ive no idea where it could be coming from.

[Black Sheep]

Ha ha ..... I've been parked literally a hundred or so meters away from kitz's driveway, a few times over the last 12 months. 

I do have a 444B as well. It would need me to be seconded over there again though, to be able to utilise it ??.

I still think (from what we read), that the faulty UG plant needs replacing in order to give the circuit a fighting chance at rejecting the 'noise'. A fully functional twisted pair may well show a different graph to the one that appears to be REIN ?

[burakkucat]

I still think (from what we read), that the faulty UG plant needs replacing in order to give the circuit a fighting chance at rejecting the 'noise'. A fully functional twisted pair may well show a different graph to the one that appears to be REIN ?

I agree. As does N*Star and many other kitizens. 

[Chrysalis]

kitz we may found out now if im banded is another power cut

--edit--

yeah I appear to be banded at 74mbit.

It appears when DLM takes action it looks at the SNRM, and if its low it will apply banding instead of interleaving.  This happened to me twice in similar situations so I dont think its mere coincidence.

74mbit may be a happy medium, as at 4.5db snrm, errors should hopefully never flip DLM and I still have a higher sync speed than normal.

[kitz]

I've been watching what DLM has been doing to my line.   With having had a full reset Ive started with a clean sheet.

1st offence -  Applied INP 3.    Removed after one full day of ILQ green.
2nd offence - Applied INP 3.    Removed after 10 days of ILQ green

It appears when DLM takes action it looks at the SNRM, and if its low it will apply banding instead of interleaving.

DLM monitors for MTBE and MTBR (not the SNRM).  That definitely hasn't changed.  It should apply INP before banding.  There is one exception where the line may go straight to being banded and thats if your line goes ILQ scarlet from excessive MTBR, but Im sure you would know if that happened.

Unless Im missing something I can not see any indication from your stats to indicate that the line is banded at 74Mbps, but rather ~74Mbps is the physical limitation of your lines max sync speed.  I cant even see anything on your Max Attainable which shows the line is capable of syncing at more than ~68.5 Mbps under normal circumstances. 

Bear in mind the 'new' Target SNRM for most lines is now 6.3dB.     The only reason youre managing to hold a higher sync rate if you come back online fractionally before your disturber, which then causes your SNRm to dip to circa 4.5 dB.

What looks like to me is happening is that you are syncing up seconds before your disturber, which is why you appear to start at 4.5dB.   DSLstats isnt managing to catch your actual stats at sync time and by the time the first stats are harvested your disturber is also already back online. 

[NewtronStar]

Bear in mind the 'new' Target SNRM for most lines is now 6.3dB.

Glad you noticed this because no way can I manually re-sync the modem to exactly 6.0dB on the downstream like we used to it's always 6.+ dB

[NewtronStar]

Kitz welcome to Atmospheric line conditions where the SNRM lowers in the evening now all the engineers i've had say my pair balance is excellent via this JDSU but they have never hooked it up in the evening time when the SNRM drops cause the OR engineers don't attend a customers premises at 6pm to 10pm.

If they did they would see a big difference 

[burakkucat]

We are able to clearly see when the metallic pathway is behaving in "defective mode" (whatever that may be).

Take a look at the high frequency end of the Hlog plot. I attach a screen-scrape, from just a few minutes ago, in which we can see a significant "droop" at the highest frequency sub-carriers. 

At other times, we have seen a perfectly normal shape to the curve for those highest frequency sub-carriers.

Such a change should not be seen, as it is indicative of physical changes occurring to the metallic pathway.

[Chrysalis]

kitz I simply looked at the QLN for the current sync and compared it to my previous sync during the power cut, they both every comparable, and this QLN is actually better (then my previous 79999 sync).  On the previous power cut I synced at 80mbit, on this power cut I am at 74mbit.

The other occasion when I got banded it was in exactly the same circumstances, the line was synced at significantly higher than the attainable, it breached the ES threshold, and was banded (which lasted until I had the DLM reset remotely by the openreach support desk).

I accept what you saying about what the DLM monitors, however the two events are incredibly coincidental.  We also know that we dont know everything about DLM as e.g. some people get banded, others get interleaved for seemingly similar events.

I have asked sky to send me a line test result to confirm the banding.  Whether they do or not remains to be seen, as their tech support is dumbed down for the masses.

So this is what I know about the events on my line.

I breached the DLM error threshold by a large amount.
The morning after, my line profile was changed, as the dslam initiated a resync.  None of the visible parameters had changed tho, the only parameter not visible is the banding.
There was then a power cut shortly after.
During the sync event after the power cut QLN is marginally improved from the previous power cut which managed a 80mbit sync.
The new sync is around the amount expected for a 74mbit banded line.

Your suggestion is that 3 fluky things happened?

1 - I escaped DLM action.
2 - The resync the morning after I breached DLM error thresholds, a resync occured for another unknown reason.
3 - by coincidence I just happen to have synced just below 74mbit.

[kitz]

I still say it doesnt make sense to band above what the line can sync at.   If you look at your max attainable, you can see its not possible to sync at a higher speed.

If you were banded, then your max attainable would be higher.   Banding has no effect on max attainable sync speed in the same way that 80Mbps has no effect on max attainable.   There is something else going on with the ECI cabs.

>>> During the sync event after the power cut QLN is marginally improved from the previous power cut which managed a 80mbit sync

Have you looked at your power output levels recently?   I keep meaning to make a separate post about this.   There's some really weird stuff going on with the ECI cabs and power levels which I suspect may be limiting our speeds.   Huawei cabs do not appear to be affected and have much higher power output.   Then look at what those on ECI cabs have been going through..  Gradual erosion which in theory will affect our max sync speed.

Last year my power output was always crica 15dBm.  Then it dropped to circa 6dBm, now its only at 4.4dBm.
Look at ronskis stats, look at les70's - in fact a lot of the regs on ECI cabs have severely had their power reduced.
Why Ive no idea.  What I can see though is when I took that first big hit to my power, was the same day that my sync speed took a loss down to 75Mb.   Those on Huawei's dont seem to be affected and still have power circa 13dBm +

So not only do we not have g.INP and no prospect of vectoring, now weve had our power cut back drastically for some obscure reason.
Go through the list on MDWS and look at power levels for the Huawei cabs and you will see they havent changed.   Then look at the figures for those on ECI's, we are only getting a fraction of the output power compared to what we used to get.