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BT DLM Testing - Volunteers Please

Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: ‎04-04-2007

BT DLM Testing - Volunteers Please

Hi all,
BT are about to start a DLM test that will allow ISPs to set specific line profiles on individual customers' lines including setting a hard over-ride on the line so that DLM can't change it.
The trial is set to begin in early January so we're looking to get together a list of up to 100 volunteers whose lines we can test out. We'll be using some staff and a couple of our test lines but the more volunteers we can get the better. So if you're interested in taking part (Asbo your name will be already on the list Smiley) please add a reply here.
It would also be useful to post what line profile you want us to set. We don't have the final list yet but it's likely we'll get a choice of the following options:
Interleave - off/on
Target SNR - 6/9/12/15dB (possibly 3dB as well) on both upstream and downstream
Standard set of banded profiles
If the choices are different we'll let you know.
Any questions please ask.
92 REPLIES
32110
Grafter
Posts: 147
Registered: ‎30-04-2009

Re: BT DLM Testing - Volunteers Please

Dave,
So in simple terms, are you suggesting that for the trial we could select a fixed target SNR that the DLM won't change? Your wording 'Standard set of banded profiles' worries me as many of us know what a problem being banded can mean - could you elaborate please.
If it all went wrong is there a way out?
Given satisfactory answers I could be interested.
scootie
Grafter
Posts: 4,799
Thanks: 1
Registered: ‎03-11-2007

Re: BT DLM Testing - Volunteers Please

well i dont use this line as main line any more so wont be able to do much close watchin of it till am up running at my new ome in manchester and can remote login to this line but looking at what youve said if possable it would be nice to have this setup on this line.
interleave on
12db maybe 9db now its running on interleaved
upstream left at the default 6db NM
on the profile front am abit confused how thats going to work, idealy banded profiles turned off but if thats not an option then the 2272- 4554 profile range would be best for this line
can you clear up how the banded profiles are going to be used, as what i was looking for from the change was just to have the option to turn banded profiles off, which with a setup like that i would presume the DLM with its fast changing of noise margins would be perfect as it would find the perfect noise margin on its own but with the added bounus of the DLM not being able to band your line for months on end
if i dont get chance to check up on this before the changes take place can you use what options that become avaible to you to set this line up as close to the above setup up.
thanks dave
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: ‎04-04-2007

Re: BT DLM Testing - Volunteers Please

Yep, for the period of the trial we would be able to select one of a number of available line profiles. Now assuming that they the ones available are the same as now that means you can set the target SNR to be fixed to one of 6,9,12 or 15dB and possibly 3dB and the target would be set permanently at that value unless we requested it to be changed to something else. You would also have the choice of switching interleaving off or on as we do now or you could set the line on to a banded profile (the choice is there if you want it but I suspect most won't want to choose it).
Essentially what we'd be able to do is set it to whatever we want (6dB Fast mode for example) and it would always be on 6dB fast mode. Or we can set it permanently on a banded profile (say the 2-4Mbps one) and it would always be on that until we requested it changed. It's pick a profile and no matter how stable or unstable the line becomes it will never shift from that profile. Put it on 6dB fast and it loses sync every 5 minutes the target SNR won't change, the interleave won't change and it won't go on a banded profile. SImilarly put it on the 4Mbps banded profile and it stays stable with zero errors it will never have the profile removed.
If the profile selected is inappropriate then we can request a different one (we're allowed to change each line a maximum of once per day with the change taking effect within a few hours) or we can put it back where it was and back that line out of the trial.
scootie
Grafter
Posts: 4,799
Thanks: 1
Registered: ‎03-11-2007

Re: BT DLM Testing - Volunteers Please

with that info i will go with this setup.
interleve on
12db on the downstream (can allways try 9db at a later stage)
default 6db on the upstream
to start with banded profiles switched off,
if the line starts syncing to high and causing drops ect on either the 12 or 9db i will  try one of the bnaded profiles to cap the downstream to correct any unstablity before upping the NM to see if thats better than upping the NM
Glad to see BTw doing somthing proactive for a change, any one would think its christmas  Grin
Superuser
Superuser
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Registered: ‎30-07-2007

Re: BT DLM Testing - Volunteers Please

Dave,
Do you need to be on ADSL2+ already to be part of this trial ?
If not then I would be interested, I like a reasonably stable line so something like the following would be preferable for me:-
Interleave - off
Target SNR - 9 on downstream 6db  upstream
Note, line currently synchs at 8128k with about an 8db margin ( 6db target I assume! ).
scootie
Grafter
Posts: 4,799
Thanks: 1
Registered: ‎03-11-2007

Re: BT DLM Testing - Volunteers Please

hum am like a kid in a sweetie shop with this  Smiley
out of intrest would this be a likely setup that could be used.
interleave on
both up and downstream NM's kepted at the default NM's ie the DLM is able to pick and choice as it does now
banded profiles off
that would be my ideal setup and what i had in mind from the start when asking for a change to be made to the DLM, ive allways said i like how fast the DLM reacts to changes but just didnt like how it would jump from 9db to 15db on band at the first sign of slight trouble
if not set it up as in reply 4
thanks
VileReynard
All Star
Posts: 11,136
Thanks: 294
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Registered: ‎01-09-2007

Re: BT DLM Testing - Volunteers Please

Would it be possible to specify:-
Download noise margin:- 3dB
Download sync - as high as possible
Upstream noise margin - whatever gives about 1Mbps

I have a pretty stable line - I presently use DMT to force the noise margin down to about 4dB.
I will be perfectly happy if the line re-syncs several times a day.
If you can do all this, I'd like to go on the trial.

Community Veteran
Posts: 3,789
Registered: ‎08-06-2007

Re: BT DLM Testing - Volunteers Please

Count me in!
as a perfect 8128k/20CN user, it's interesting to see I'm put on a 6meg banded profile under 21CN due to line errors.  The ability to force it to a particular SNR or band could be an interesting test case.
account: zubel2
B.
chrisyoung
Grafter
Posts: 110
Registered: ‎22-04-2009

Re: BT DLM Testing - Volunteers Please

O this sounds good i can finaly get of this banded profile.
count me in
interleaving off  , is off already anyway
banded profile off
6db noise margin
i had a profile of 19m on NM of 3db but not sure i want to go to that extreme yet see how 6db goes first
Superuser
Superuser
Posts: 6,913
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Registered: ‎30-07-2007

Re: BT DLM Testing - Volunteers Please

Quote
Glad to see BTw doing somthing proactive for a change, any one would think its christmas

Let's face it, its about time!. The LLU operators have been working this way with a fixed target SNR for a long time now, albeit its not that easy to change the target with some operators. If BT are going to work this way its got a good chance of being better than the DLM as it currently stands. As long as they provide a reasonably easy ( read automated ) way for ISP's to change the targets after the trial.
I must admit I'd been dreading the move to 21CN but with something like this I think it could be much better!.
Highlighted
Moderator
Moderator
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Registered: ‎06-04-2007

Re: BT DLM Testing - Volunteers Please

I'm happy to help in this trial, too Smiley

Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
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deltec
Dabbler
Posts: 12
Registered: ‎18-08-2009

Re: BT DLM Testing - Volunteers Please

Hi,
Count me in on this trial.
For some reason my profile keeps getting banded to 4500k (which is lower than using ADSL Max).
account: deltec
I'd look to getting my line SN around the 9db initially, hopefully moving to 6db downstream (upstream it is currently 6db)
hadden
Grafter
Posts: 486
Thanks: 2
Registered: ‎27-07-2007

Re: BT DLM Testing - Volunteers Please

Nice.  Smiley
I'm happy to volunteer.
I would opt for:
Target SNR6dBCurrently I over-ride it up to 6.2dB-ish, for stability.
Profile4500, if possibleAs I can almost get that now, but 4000 if that suits the trial better, as I'm confident that can be sustained.
InterleaveOnThat's what I have now.

32110
Grafter
Posts: 147
Registered: ‎30-04-2009

Re: BT DLM Testing - Volunteers Please

I would like to be included please with following parameters:
SNR 6
Interleave ON
Banding OFF