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[Butters]

Hey,

Just a quick question, what one is my sync speed, is it the MAX or Rate (kbps) speed?

A little background on what I have been doing....

I have only just left the 7 day migration period, during that period I have been playing with my SNR settings on the netgear router.

I originally started with 3300kbps running at 6.1 SNR, I tweaked myself up to a profile of 4500 but my SNR was running at 2.6-3.6 (set at 60%), pushing things further still I dropped my SNR to 45% and it took my sync rate up to 6213 kbps, SNR didnt really change much but I was having a lot of dropped packets which was to be expected, so I took it back up to 60%.

Today I wake up and find my SNR is back up to 6.1 (even though it is still set to 60%, my IP profile at 5000 and my sync speed at 5634 (just outside the 5000 Profile range)... so I drop my SNR% to 47% and get the stats I have below.

Link Power State: L0
Mode:         G.DMT
Channel:      Fast
Trellis:      ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):   6.3      23.0
Attn(dB):   46.0      29.0
Pwr(dBm):   19.4      11.9
Max(Kbps):   5728      1108
Rate (Kbps):   5696      448

As you can see, even though i have dropped my SNR % it has stayed around the same mark, but my sync speed has increased slightly, which puts me (i think) back into the 5000 profile range.. I have checked my errors and they are nearly non existant (23 CRC errors in the last 2 hours).

Anyone know how this has happened?

If I had been running my SNR at 47% before today I would have had 1000's of crc errors. I am not sure how my SNR has increased, yet I have stayed in the 5000 profile range.. Is it because the 7 day settling in period has ended? looking at the stats above, am I actually in the 5000 IP range again?



Sorry for the long post

Regards

[roseway]

Hi and welcome.

Your connection speeds are in the line labelled 'Rate'. The other figures are an estimate of what the line capability is, based on the conditions at the time the connection was negotiated.

What's probably happened is that the frequent re-syncs resulting from your experiments have caused DLM to flag your connection as unstable, and the target noise margin has been increased (probably to 9 dB) to stabilise it. By setting the noise margin tweak to about 50% you've brought the noise margin back down to about 6 dB. If you carry on tweaking frequently, you will very probably trigger a further increase in the target noise margin, so I strongly advise that you leave it alone for a day or two to settle down.

To be honest, I think that you're pushing your connection a bit too hard, and going much below 6 dB for the target noise margin is asking for trouble in the form of instability. I would leave it right where it is now, and hope that in a few weeks the target noise margin will automatically fall back to 6 dB.

[HPsauce]

asking for trouble in the form of instability.

Or worse TBH.  Asking for trouble in the form of a raised target SNRM which typically only drops in 3dB steps and then only after a whole month of recorded stability.
And if it gets elevated to 15dB it can stay "stuck" there, something you definitely don't want.

BT's systems really don't respond well to what you're doing and the outcome can be painful. 

[Butters]

Thanks for the replies guys.

I wasnt going to play with it anymore as an ip profile of 5000 is what I was aiming for   .

What I do find strange is this.

Starting Profile before any tweaks 3500
Starting SNR before any tweaks 6 to 6.5

Profile After Tweaks 5000
SNR after Tweaks 6 to 6.5

If BT increased my SNR to 9db and I tweaked it back down to 6db, how comes my Profile and connection speeds havent fallen back down to the 3500 profile range?.

My line seems quite stable with a lot less errors than yesterday or the day before.

Hope i'm making sense

[roseway]

The initial IP profile may have been simply a starting value, which later got updated to reflect your actual connection speed.