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How long until DSLAM recgonises line stability?

Jax
Dabbler
Posts: 22
Thanks: 4
Registered: 08-09-2010

How long until DSLAM recgonises line stability?

Hi folks,

My questions are, how long does it take the DSLAM to realise my line is stable and up the speed?

 

And how much of an increase am I likely to see if the SNR is set from 11 to 6, if 6 is the target like in the ADSL days?

 

24 days ago g.inp was enabled on my line, from I think an ECI cabinet. INP is set at 46 on the downstream and not enabled on the up. Interleave has changed to 1/1. ES/hour are 0.42/1.28 (down/up), both better than before g.inp.

Since then my line hasn't dropped once, but the SNR has changed from ~6 to 11dB. Consequently my measured speed has dropped from about 43/12 to 40/9. My Billion 8800NL reports the sync at 44000 down and 11089 up. Now, losing 3 mbit/s is kind of negligible but according to DSLstats my attainable rate is 57 Mbit/s and it would be nice to get up there.

 

Currently, the BT Performance Test says:

Download speed achieved during the test was - 40.06 Mbps
For your connection, the acceptable range of speeds is 34.03 Mbps-42.54 Mbps .
Additional Information:
IP Profile for your line is - 42.54 Mbps

and Plusnet's Current line speed is at 42.4 Mb

8 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 2,144
Thanks: 372
Fixes: 116
Registered: 22-08-2015

Re: How long until DSLAM recgonises line stability?

Hello there. DLM on Fibre assesses the connection every 24 hours and will make changes if required.

I would suggest having a read of this article:

https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799

In regards to the speed if your sync is below the minimum value of the estimate at http://dslchecker.bt.com I would recommend heading over to http://faults.plus.net completing the broadband troubleshooter if necessary to raise this as a fault.

Hope this helps
From when I joined the Plusnet Help Team in May 2017 my main Community account is @Gandalf.
If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Staff
Jax
Dabbler
Posts: 22
Thanks: 4
Registered: 08-09-2010

Re: How long until DSLAM recgonises line stability?

Hi Anoush,

 

Thanks for that, but that article doesn't mention g.inp. My speed is fine, but my point was that since g.inp has activated on my line the SNR has increased from 6 to 11, and the stability has been 100%, at least according to the router. Uptime has been 24 days, no drops. Assuming the SNR target is 6, then I have a further 5 dB equivalent of speed inherent in my line, and I'd like to know how long it takes the DLM to notice that there's scope for improvement.

Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: How long until DSLAM recgonises line stability?

Hi Jax. There is no definitive answer to that question. Also Modem predicted attainable rates aren't necessarily accurate, a lot will depend on usable tones at any given time. If your SNRM is very stable at ~11dB then I'd be inclined to try logging into the 8800NL, click Disconnect to drop the PPP session (assuming it has that capability - not checked personally) wait about 30 seconds and then power it off. Stay off for 1 hour - (60 minutes minimum). Then power up again. Once sync is achieved you may need to click Connect for a new PPP session (it may do it automatically). Do all this in daylight hours ideally around the middle of the day when noise levels generally ought to be quieter.
There's absolutely no guarantee that you'll achieve better, indeed it's always possible it might be worse, but with a stable 11dB SNRM it ought to be better.

Jax
Dabbler
Posts: 22
Thanks: 4
Registered: 08-09-2010

Re: How long until DSLAM recgonises line stability?

Thanks Anotherone, I'll give this a go tomorrow.

Jax
Dabbler
Posts: 22
Thanks: 4
Registered: 08-09-2010

Re: How long until DSLAM recgonises line stability?

Well, I did as suggested and disconnected the session, turned the router off, waited over an hour and switched it back on again.

 

I'm still syncing at exactly 44000 kbps (up sync is 10745 little less than before). Attenuation is 21.0, SNR is still 11.6dB, and currently the ES/hour is at 2.8.

 

So is the target for the DLM still 6 SNR like ADSL2, and is there any way of getting it there? It's been 27 days with the above stats now, with the only drops due to me, twice in 27 days, turning the Billion off.

 

Any further info greatly appreciated.

Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: How long until DSLAM recgonises line stability?

In that case it's pretty obvious that your connection is Banded. 44Mbps is one of the banded speeds. Prior to g.INP did you have any line faults? You could try hanging on a few more days to see if DLM does anything now since this power off, other than that getting one of Plusnet's Help Team to have a look, but historically getting a Reset on Fibre without a fault is difficult to say the least.

Jax
Dabbler
Posts: 22
Thanks: 4
Registered: 08-09-2010

Re: How long until DSLAM recgonises line stability?

Thanks again Anotherone. There were a handful of lost connection moments but I couldn't tell you how many. I was getting a speedtest result of around 43 (used to be 53 when I first got FTTC but that's another story). Since g.inp it's dropped to about 40mbps. If I remember correctly the interleaving was somewhere in the region of a value of 1600 according to DSLstats.

 

It seems a bit backward that getting off banding is awkward. How was it managed by others I wonder? Not knowing anything about how it all works, one would think that changing software settings would be trivial, and within the power of the ISP. I was under the impression that as we evolved from dialup->ISDN->ADSL/2->Fibre that things moved away from under BT's/Openreach's control and the ISPs had more options.

Community Veteran
Posts: 19,100
Thanks: 437
Fixes: 21
Registered: 31-08-2007

Re: How long until DSLAM recgonises line stability?

It used to be the same on ADSL years ago, then eventually ISPs were able to reset, change settings etc. It'll come on Fibre. You never know someone from Plusnet may be able to work some magic for you.