Openreach FTTC with 3dB

MrSaffron

My parents has complaint about their FTTC has disconnected every days lately. They have no problem before Openreach has changed DLM on their line with 3dB SNR target.

I have a look at their plusnet hub one router with helpdesk and can see their line at 2.5dB downstream and 6.1dB upstream and check the logs as I can see everydays of DLM made change at their downstream SNR from 3.1dB to 4dB, 5dB and back to 3dB and so on.

I think the only way to stable their line is to request Plusnet to ask Openreach to DISABLED Target SNR 3dB and locked at 6dB default to keep their line stable.

Can Openreach do this or can't do it, up to DLM to do this way? My parents are getting fed up with it and want to stay stable as it was. Their line was stable from 2014 until few months ago when DLM kicked in 3dB and caused more problems.

No idea why you aim the question at MrS.
This is a community forum.

It can't be done though.

You could ask Plusnet to move your parents from the DLM Speed profile that Plusnet use to the Standard profile.
It would reset the DLM and be less likely to bounce between SNRM targets.

A bit of me thinks .. �it�s just desserts� after all those countless posts by the OP whining about DLM and speed caps etc in the past.

Speed is nothing without stability.

In reply to a post by j0hn83:

No idea why you aim the question at MrS.
This is a community forum.

It can't be done though.

You could ask Plusnet to move your parents from the DLM Speed profile that Plusnet use to the Standard profile.
It would reset the DLM and be less likely to bounce between SNRM targets.

It can be done by Openreach as part of a visit to the home, I�ve arranged that in the past and was told that it will stick until another DLM recalc is requested.

@j0hn83 I�m not sure how Plusnet would arrange that though, as they can�t do it themselves. They may have some kind of mechanism to request Openreach do this, but that request could be turned down.

Replying to Icaras but really a general question.

What is involved in a DLM re-calc? Is it so involved or so disruptive of the network that OR reserve the right to do it themselves to avoid excessive disruption? Or, with my cynical head on, is it a hangover from the old monopoly days and the remnants of the old Civil Service mentality still survive in some of the OR processes?

BT Wholesale have three stability options that correspond to the three Openreach ones, though confusingly differently named. (Or at least they used to be).

AIUI any CP can request a change of stability setting. For BT Wholesale based ones it would be by requesting a change to theirs, and hence through that route to the Openreach one. Sky, TalkTalk et al would do it directly to Openreach.

There's actually 4 DLM profiles.

Speed, Standard and Stable are the ones frequently discussed.
Speed and Standard are the most common.
I'm not aware of any residential ISP's using the Stable profile.

I've always understood that none of the 3 DLM profiles mentioned above can have any manual intervention. The DLM is entirely automated.
SNRM can't be fixed or changed manually.

There is a 4th DLM profile often overlooked or unknown to many.
This is named "Custom" and AIUI can be set to a fixed setting like you suggest.
Documentation for ISP's tells them the Custom DLM profile should only be used on test lines.
I've no doubt the OpenReach DCoE could set this up for unique troublesome lines and perhaps that's what was used in your example.

Would be interesting to find out if when this was done on the job you mentioned if you could see the DLM profile in use and if it was the Custom profile.

@j0hn83 I�m not sure how Plusnet would arrange that though, as they can�t do it themselves. They may have some kind of mechanism to request Openreach do this, but that request could be turned down.

OpenReach introduced a trial for ISP's to request DLM resets a while ago.
Plusnet are the most willing to to do this with many recent examples on their forums.
They request it from BT Wholesale who in turn pass that on to OpenReach.
It can and does get rejected on occasion.

Many ISP's won't request it at all.

I had a similar problem with TalkTalk. After several complaints someone called me, I explained the problem, He there and then put me on a fixed 6dB.

In reply to a post by Brunel:

I had a similar problem with TalkTalk. After several complaints someone called me, I explained the problem, He there and then put me on a fixed 6dB.

That's ADSL.

No ISP has DLM control on FTTC.

Icaras is an OpenReach engineer and was talking about something very out of the ordinary.

Thanks for the info.