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[Chrysalis]

Given that fast path estimates by the hg612 seem to be fairly accurate (its interleaving where the attainable is whacky), my line originally could do 110mbit on my original pair.  It eventually settled in the high 60s so over 40mbit loss, before plumetting below 50 causing me to get a new pair, the new pair was stable at 71-73 for quite a long time, over a year, but in the past 6 weeks has had multiple drops and is now down to just over 66 attainable.

A 3db profile would get me up to about 77 I guess, would have been the full 80 if not for the extra crosstalk in past 6 weeks.

But remember that currently ECI has no g.inp so lines qualifying for the 3db target wont be a lot I think.

Ironically before my original pair plummeted to 50 I was synced at over 70mbit on a low margin, this actually saved me because it meant the loss of speed exceeded the 25% criteria to get marked as a GEA fault.

[NewtronStar]

Trying to work this out if your crosstalker was set to 3dB and your line was set to 6dB would that cause more crosstalk as when a crosstalker gains more sync this has an effect on the effected line by lowering their SNRm and lowering the Attainable sync.

To me it looks as if the 3dB target margin would cause more crosstalker wars

[Chrysalis]

no its power output that causes crosstalk not sync speed or snrm target the dsl signal strength is same but a lower target snrm simply means less of it is allocated as a buffer against errors

[NewtronStar]

Thanks Chry for helping me understand crosstalk a bit better I do see slight changes on the power output on the modem during a modem reboot the DS power can change by 0.3 the US can change by 1.0, so I wonder how much our crosstalkers power fluctuates.

[smallal]

It's being reported that the nationwide rollout of the lower target SNR of 3db on Infinity VDSL will be in March.
Is there a set date for this or will it happen in stages over the month?
There are also conflicting reports as to whether ECI cabinets will be included in the March rollout.
Anyone got definitive news on this?

[skyeci]

Cant see ECI getting the new snr profiles without G.INP..

[j0hn]

http://www.btplc.com/sinet/SINs/pdf/498v7p3.pdf
Page 8, section 1.2.2

1.2.2  VDSL2 noise margins Currently  the default  target  downstream noise  margin is set to 6dB.   From  March 2017 the  target  downstream noise  margin shall  be  set to either 3, 4, 5 or  6dB  –  the actual value shall  be  determined by  the  Dynamic  Line Management (DLM) algorithm based on line  stability.

No further info than March unfortunately.
ECI DSLAM's are not getting the new xdB target SNRM

[displaced]

Hehe.  Seeing this thread's subject line pop up in the Unread Posts page made me think it had gone live now   Not long to wait, though.

A quick question:  A while back, my HG612 resync'd quickly after a local power cut and I got in before other crosstalkers.  My sync rate was in the high 57's - a good 7-8MBit higher than usual.  During that time, my SNRM was around 3-4dB and, although higher than normal, my ES and SES rates were nothing to worry about. 

Is that a good estimation of what my line would be like if I were to have a 3dB profile assigned?

(I hope so.  It was speedy!)

Chris

[NewtronStar]

I guess it would be a good estimate once you get to this magic target SNRM of 3dB of course it will start at 5db then 4dB and finally 3dB and your SNRM looks quite steady and see no issues there when this new automatic SNRM is rolled out.

Just taking a guess if and when it arrives on my circuit my own SNRM changes quite a bit over 24 hours so 4dB would be the minimum the DLM will allow, of course we will not know until it's fully rolled out and it's just a trial at the moment  

[Sheepie]

Looks like DLM put me on a 3db margin last night. My exchange was NOT included in the trials.

I've gained 15mb on the downstream, but unfortunatley G-INP in still not activated, even though it is enabled at my cab, so ES are going through the roof.

[gt94sss2]

Could you

Looks like DLM put me on a 3db margin last night. My exchange was NOT included in the trials.

Could you say what part of the country/exchange you are on?

[Sheepie]

I'm off https://www.samknows.com/broadband/exchange/WNROS

[j0hn]

Looks like DLM put me on a 3db margin last night. My exchange was NOT included in the trials.

I've gained 15mb on the downstream, but unfortunatley G-INP in still not activated, even though it is enabled at my cab, so ES are going through the roof.

Looks like something else caused this. The upstream has also dropped by 3dB from 15dB to 12dB.
All the examples we've seen so far also drop in stages. From 6dB to 5dB to 4dB then finally 3dB. The upstream should remain static.

This thread is the perfect example of lots of wrong assumptions that they are on a 3dB target SNRM. Half the thread is ECI users who are excluded, and the other half were before the trial even started. There's 101 reasons that can cause a line to resync at a lower SNRM.

[Sheepie]

yes it might not be due to reduced target margin, but it is the only thing I can find to explain the drop in SNR and the quite large increase in max attainable (and therefore actual sync too).
I guess the DLM is going to do something tonight (loads of ES and ~2% packet loss). Might know more tomorrow......

[Sheepie]

Actually, the QLN graph from HG612 modem stats shows a very odd and quiet line