topic Re: DLM stability profile change on Plusnet in Broadband

DLM stability profile change on Plusnet

cbdeakin — Thu, 07 Apr 2022 22:58:21 GMT

I'm considering switching my ISP to Plusnet fairly soon.

I just wanted to check if it's possible for the DLM stability profile to be changed on request with a FTTC line? So, for example, changing the default stability profile from the standard option to the most stable option.

The main reason to do this would be to increase the probability that interleaving would be enabled on the upstream part of my line, which I've found is very effective at preventing packet loss. I noticed this packet loss in live video streaming tasks, such as game streaming on Google Stadia, other streaming services and video chat software.

Changing to a more stable DLM profile would lower the thresholds needed to enabling interleaving on both the downstream and upstream.

A bit of background:

The reason for the higher than usual packet loss on my line appears to be that the line in my street is aluminium rather than copper, which an Openreach engineer informed me tends to be prone to interference and noise.

Unfortunately, after an Openreach engineer requested this change via remote tech support*, the DLM system turned off interleaving on the upstream after a couple of days. While interleaving was enabled on the line, I experienced no packet loss during Google Stadia sessions, and the stream felt very smooth.

* Yes, Openreach do have a limited amount of control over interleaving, which was requested during an engineer visit and successfully enabled on the upstream.

Re: DLM stability profile change on Plusnet

Gandalf — Fri, 08 Apr 2022 08:50:33 GMT

Cheers for looking at signing up with us.

Absolutely, we can change the stability profile of a line to either Standard, Stable or Super Stable. Sometimes, they're referred to as Speed, Standard, or Stable. I believe the former is how BT Wholesale describes the stability profiles, and the latter is Openreach's way, but they're the equivalent of one another and just different terminology.

Taken from the Kitz website here > https://kitz.co.uk/adsl/DLM.htm this may be useful...

Stability Level	WBC Profile (20/21CN)	NGA Profile (FTTC)	Description

1. Aggressive	Standard	Speed	Prioritise speed over stability for online gamers
2. Normal	Stable	Standard	Best overall balance between speed and stability
3. Stable	Super Stable	Stable	Prioritise stability over speed for IPTV

Re: DLM stability profile change on Plusnet

cbdeakin — Sat, 23 Apr 2022 12:04:08 GMT

Hi Anoush,

Thanks for that info. Does Plusnet or Openreach have any control over the downstream and upstream interleaving settings? Or, can this only be (potentially) affected by the DLM stability profiles?

Re: DLM stability profile change on Plusnet

adam945 — Sat, 23 Apr 2022 15:54:13 GMT

We do have some form of control with DLM settings, including interleaving when it comes to ADSL broadband, FTTC is a different ballgame though, all we're really able to do is request a DLM reset.

Re: DLM stability profile change on Plusnet

Gandalf — Sat, 23 Apr 2022 20:21:16 GMT

Just to note though that we can only request a DLM reset, if a sync speed is restricted by banding. We can’t do them to reset other settings like interleaving.

Re: DLM stability profile change on Plusnet

Edinburgh_wg — Sun, 24 Apr 2022 23:38:43 GMT

Interleaving is automatically applied by Openreach equipment.

Therefore, Plusnet staff have very little control over what they can do in terms of interleaving.