Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: twinkletoes on July 07, 2018, 09:56:32 PM

Title: xdb profiles
Post by: twinkletoes on July 07, 2018, 09:56:32 PM
Hi Kitzens,

Just wondering how long it takes before the SNR profiles start to lower? I had a 3.4db SNRm before when I was on the BTW network with uno, but ever since swapping to the TTB network with them in January 2018, the OR DLM refuses to try the lower xdb profiles. I have been on a 6.3 (give or take 0.2 in that value) DS SNRm, just find it odd that my line was perfectly fine on a 3.xdb SNRm giving me the full 80/20 sync speeds.

I have had a DLM reset performed yesterday, so I'll keep an eye on my line and see what happens.

Thanks for any advice.

Steve
Title: Re: xdb profiles
Post by: Ronski on July 07, 2018, 10:30:13 PM
Roseway switched provider recently and his took 10 days to get back  to 3dB, but it does vary, my brothers line took much longer.
Title: Re: xdb profiles
Post by: andyfitter on July 07, 2018, 11:03:31 PM
Donít hold your breath. Iíve been waiting since Christmas for xdB on a line that will comfortably support it. Also took 3 months to get g.inp reapplied.
Title: Re: xdb profiles
Post by: twinkletoes on July 07, 2018, 11:35:37 PM
Thanks for the replies :) I got G.INP applied on the DS within 7 days when I swapped over, so that was pretty good! Also a few days ago I had G.INP on the US for about 24hrs before the DLM decided to turn it off again. It was nice seeing 0 ES on both DS/US. DLM is a mysterious thing in the way it works! :D

Steve
Title: Re: xdb profiles
Post by: spring on July 08, 2018, 02:01:12 PM
well upstream G.INP isn't applied unless there are errors, whether or not the DLM is behaving according to your needs is a case of luck

One of the things we noticed is that rather than the usual INP 3, the INP value would be somewhere in the 40-50 region. (which we would expect for G.INP).   It became unbundantly clear during G.INP mk1 that there were far more 'incompatible' modems in use than Openreach anticipated, so they did a botch job by only applying G.INP/INP on the upstream for lines that needed it for stability... and at the same time changing downstream to have INP applied first by default then G.INP at a later date.
Title: Re: xdb profiles
Post by: andyfitter on July 08, 2018, 02:26:07 PM
well upstream G.INP isn't applied unless there are errors, whether or not the DLM is behaving according to your needs is a case of luck

Iím not sure that explains everything in terms of upstream g.inp. Iíve had around 8 dlm resets over the past 4 years. 4 through changing supplier and 4 through faults. After each reset it is a variable amount of time for downstream  g.inp to come back, but every single time I get g.inp downstream, around a week later I get 1 or 2 days of g.inp upstream, but every time it is taken away again. It isnít brought on by errors, it seems as if dlm just gives it a try to see if it makes things Ďbetterí in some way that dlm quantifies. After it goes away it restores the upstream back to the same parameters as previously applied.
Title: Re: xdb profiles
Post by: spring on July 08, 2018, 03:06:23 PM
well for OP errors were relevant, your experience explains why DLM didn't really decide turning it on, just probing it
Title: Re: xdb profiles
Post by: j0hn on July 08, 2018, 04:18:49 PM
I'm my experience DLM applies upstream G.INP after a period of increased upstream ES. Most of the time it removes after a few days.
Some noisier lines keep upstream G.INP all the time.

For the OP, the majority of the time G.INP is applied within a few days of a ISP switch. The target SNRM (xdB) is usually lowered within a few days of that.
If it isn't lowered in the 1st week then it can take months/never/who knows before it might try it.

A DLM reset usually triggers the whole routine to start again and the target SNRM would likely be lowered in the first week.
Getting an ISP to arrange a DLM reset because the SNRM hasn't been lowered is probably a no go though.