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[kitz]

Thank you BS..  so now we have the rates at which BToR will decrease the line if the "poor count" threshold has been exceeded.

Since they arent using SNRm to improve stability - instead lowering the line rate which increases the SNRm.

Next question - would they be 'borrowing' the BTw system of  SNRm -> interleave -> SNRm -> interleave increments only its cap ->interleave -> cap -> interleave...  which would be the logical step.

Still no idea of the poor and good count triggers though. It will probably equate to a number of days.     

[Chrysalis]

I think its more like.

Interleave -> Interleave -> Cap

although taking colin's case into account it would seem they have made it more complex whereby if they recognise certian 'types' of instability they will cap first instead of interleaving.

[kitz]

I think its more like.

Interleave -> Interleave -> Cap

Ive no doubt that it likely will be...in fact it may even be interleave -> interleave -> interleave -> cap in some instances.

This is an area where users observations become useful 

[waltergmw]

@ Colin S,

Spot on with your assumption !

We might also suggest that the execrable subcontractor practice of commissioning VDSL services without the vital ability to perform full pair quality and VDSL line tests should be ceased immediately as it must surely contravene the sale of goods and services act.

Were that the case, perhaps Walter's wheelbarrow would not burn quite so much rubber !

Kind regards,
Walter

[kitz]

@ Colin S,

Spot on with your assumption !

We might also suggest that the execrable subcontractor practice of commissioning VDSL services without the vital ability to perform full pair quality and VDSL line tests should be ceased immediately as it must surely contravene the sale of goods and services act.

Were that the case, perhaps Walter's wheelbarrow would not burn quite so much rubber !

Kind regards,
Walter

I wasnt sure what you meant but looking back I assume you mean this

Have I got that right, and am I right in guessing that your point is that even 'bad' lines (that perhaps might have merited activation in a 'stable' profile) are still activated in an open one?

Personally I find it fair that all accounts are provisioned on an open profile.  Yes there may be some instability for a few days whilst the DLM kicks in, but at least it gives a long line the opportunity of getting the best speeds it can in the long term.  There may be some longer lines which run pretty stable this way.  We all know of the used phrase "Give the line up to 10 days to settle in" really means give the DLM chance to find the best level.

Whilst I agree with you on the use of subcontractors, that is a matter separate from the DLM.  Even with a BToR install and all his kit, he would not be able to second guess how the variance of SNRm will affect the line over a period of hours, nvm over a longer period.  Things could get even more interesting with the advent of self install FTCC, but again a different topic.

What this thread has disclosed is the DLM being able to identify & mark 'very poor' lines. These are fast tracked through the DLM penalties and therefore they should stabilise much quicker.

The reason I agree with the open profile,  is the alternative system is much worse.  In the early days of Max dsl, how many good lines got stuck at 2Mb and would have sat there forever not able to reach its full potential.   That said my favourite DLM of all time is that of Be* Broadband.  It had a KISS approach..  but regretfully I fear that even this may be too complicated for non-technical users.  It may also have worked fine on adsl2+ but its doubtful whether it would have been quite so straight forward with all the additional vdsl frequency bands, and they too may have had to come up with an alternative dlm if they ever had gone down the vdsl route.

[Chrysalis]

yeah a open profile is better than other types, sky is an example, their DLM starts of slow and works its way up, thats worse than starting fast as possible.  Like you said kitz I also remember those 2mbit start profile son adsl max (which often got stuck as well).

[kitz]

yeah a open profile is better than other types, sky is an example, their DLM starts of slow and works its way up, thats worse than starting fast as possible.  Like you said kitz I also remember those 2mbit start profile son adsl max (which often got stuck as well).

My line was forever getting stuck on 2Mb.  I hated it, it happened so many times and would take ages to get reset.  Its one of the prime reasons I moved to Be as soon as they came here (annex-m was the other reason)

Sky's is just plain silly.. my parents line is stuck at about 1.6Mb when it should be getting about 6-7Mb. 
Months later and its still not budged from 1.6Mbps...  I still need to sort it and tackle Skys support one day.. because dad cant. The non technical users have a hard time and have to put up with the reboot your router rubbish which of course doesnt make the slightest difference.

[ryant704]

I swear the DLM hates me, previous sync of 88 days and before that 36 days. Had a lovely power blue transformer explode causing a couple of instance power cuts, DLM now wants to put banding on my line at 20/4.6 with Interleaved off (normal depth 450ish, 3INP). 34 days later and still not back to my old 27/5.2 though for some reason all the daytime RFI/REIN or what ever it was has now cleared, maybe the power cut broke the issue for me?

[Ixel]

I swear the DLM hates me, previous sync of 88 days and before that 36 days. Had a lovely power blue transformer explode causing a couple of instance power cuts, DLM now wants to put banding on my line at 20/4.6 with Interleaved off (normal depth 450ish, 3INP). 34 days later and still not back to my old 27/5.2 though for some reason all the daytime RFI/REIN or what ever it was has now cleared, maybe the power cut broke the issue for me?

Similar to me. I think DLM is setup so that if 'instability' is still detected after a number of consecutive 'negative actions' (such as applying higher levels of interleaving) then it bands the connection at a lower speed and disables interleaving altogether, without any future prospect of changing unless reset. Mine must've been at 60/20 with no interleaving for a good number of months now, with the occasional disconnection every 30-45 days when something decides to change the output power.

[ryant704]

I swear the DLM hates me, previous sync of 88 days and before that 36 days. Had a lovely power blue transformer explode causing a couple of instance power cuts, DLM now wants to put banding on my line at 20/4.6 with Interleaved off (normal depth 450ish, 3INP). 34 days later and still not back to my old 27/5.2 though for some reason all the daytime RFI/REIN or what ever it was has now cleared, maybe the power cut broke the issue for me?

Similar to me. I think DLM is setup so that if 'instability' is still detected after a number of consecutive 'negative actions' (such as applying higher levels of interleaving) then it bands the connection at a lower speed and disables interleaving altogether, without any future prospect of changing unless reset. Mine must've been at 60/20 with no interleaving for a good number of months now, with the occasional disconnection every 30-45 days when something decides to change the output power.

Worth noting I had a DLM reset on Monday now on 26.7/5.1 and I'm still on Fast Path!

Was rather funny the CS lady said my line wasn't banded, then she tried telling me the NGA help desk didn't exist. I did have some laughs but god do they wind me up...

[Ixel]

I swear the DLM hates me, previous sync of 88 days and before that 36 days. Had a lovely power blue transformer explode causing a couple of instance power cuts, DLM now wants to put banding on my line at 20/4.6 with Interleaved off (normal depth 450ish, 3INP). 34 days later and still not back to my old 27/5.2 though for some reason all the daytime RFI/REIN or what ever it was has now cleared, maybe the power cut broke the issue for me?

Similar to me. I think DLM is setup so that if 'instability' is still detected after a number of consecutive 'negative actions' (such as applying higher levels of interleaving) then it bands the connection at a lower speed and disables interleaving altogether, without any future prospect of changing unless reset. Mine must've been at 60/20 with no interleaving for a good number of months now, with the occasional disconnection every 30-45 days when something decides to change the output power.

Worth noting I had a DLM reset on Monday now on 26.7/5.1 and I'm still on Fast Path!

Was rather funny the CS lady said my line wasn't banded, then she tried telling me the NGA help desk didn't exist. I did have some laughs but god do they wind me up...

Lucky! I've had no luck getting mine reset, so I've lived with 60/20 for months lol.

[ryant704]

I swear the DLM hates me, previous sync of 88 days and before that 36 days. Had a lovely power blue transformer explode causing a couple of instance power cuts, DLM now wants to put banding on my line at 20/4.6 with Interleaved off (normal depth 450ish, 3INP). 34 days later and still not back to my old 27/5.2 though for some reason all the daytime RFI/REIN or what ever it was has now cleared, maybe the power cut broke the issue for me?

Similar to me. I think DLM is setup so that if 'instability' is still detected after a number of consecutive 'negative actions' (such as applying higher levels of interleaving) then it bands the connection at a lower speed and disables interleaving altogether, without any future prospect of changing unless reset. Mine must've been at 60/20 with no interleaving for a good number of months now, with the occasional disconnection every 30-45 days when something decides to change the output power.

Worth noting I had a DLM reset on Monday now on 26.7/5.1 and I'm still on Fast Path!

Was rather funny the CS lady said my line wasn't banded, then she tried telling me the NGA help desk didn't exist. I did have some laughs but god do they wind me up...

Lucky! I've had no luck getting mine reset, so I've lived with 60/20 for months lol.

Hmm, it's an advantage when you know the majority of the engineers. I told him what needed to be done and he did it, was as simple as that.

[kitz]

Wouldnt it be sooooooooo much easier if BT also had a way that the ISPs could request it too.

Perhaps in time BToR will learn that its better to pass this over to the SP too.  Its a waste of a BToRs time and resources to send an engineer out just to get this done.   In the early days of maxdsl, the ISPs had to battle with BTw to get a DLM reset and so many manhours will have been lost on both sides.   Letting the SP request it, simplifies things all round especially when its obvious that its the reason why a line is held short of its capabilities. 

[Chrysalis]

Kitz it would but I think they have done this to deliberatly have a barrier in place, it looks clear to me openreach want a situation where its fully automated and overides are a complete last resort.  I expect their motivation is that a line heavily interleaved is less likely to generate a complaint than a line just been reset but is dropping out due to a fault (which openreach find cheaper to hide via DLM than to fix).

[Black Sheep]

DLM wasn't introduced to 'hide' faults. It was implemented to stabilise circuits, with parameters built in such as 'Fault threshold rates', that if breached would entitle the EU/ISP to have a fault built.

If it was given over to the ISP's, then a scenario could develop whereby they themselves just carry out continual resets on a circuit thus masking a potential line fault. The subsequent downward trend in VDSL faults raised against the ISP, would probably be used as a marketing aid as well ??

I agree it isn't perfect, and can be aggressive sometimes, but to suggest it has been designed, or managed in such a way as to hide problems, is akin to a conspiracy theory, IMO.