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[GaryW]

Hi all,

I'm a fair distance from an ECI cabinet, DS sync banded at 14999 and US is a little over 500 (yes, that's the correct number of zeroes!) and only US0 and DS1 are being used.  If I look at the SNRM on my line, although the DS changes a lot over the course of the day/night, the short-term fluctuations are very slight (typically +/- 0.1dB).  However, if I look at the US SNRM the behaviour is completely different - the average stays constant throughout the day/night but the short-term fluctuations are much greater (typically +/- 0.7dB).  One of the effects of this is that when I resync, the US sync speed can be anywhere between 495 and 535...and I'd like to nudge it up a bit as every little helps 

Is this level of US fluctuation normal (or even normal-for-ECI!)?  If not, any thoughts on what may be causing it and if there's anything I can do about it?  (Dslstats picture attached)

[Ixel]

I don't experience this amount of SNR fluctuation on my line (for the upstream). That's quite a lot of fluctuation on that graph. The only time I had some fluctuation was when I was using homeplugs temporarily and that affected my D3 band.

[kitz]

My upstream often goes down by 2dB in the evening.   


My graphs are set to 2 hrly
 - First graph is this evening
 - Second graph is yesterday eve.

By around ~ 8am it will be back to circa 12dB, then it will start to drop again ~5:30pm to circa 10dB.
As its currently cycling around daylight times I just assume its atmospheric RFI as the timings dont appear to coincide with anything else that I'm aware of.     

The jitter isn't always there - from a few years of observation, that usually only kicks in if I've had a remote resync from the DSLAM.  I can sometime cure that by leaving the modem switched off for a period of time, but the upstream daily swing is there most days.

Some lines also get it on the downstream - a lot of lines get 1dB daily swing & anything up to 3dB is considered within normal range. 
It's why DSL has SNR Margins sufficient to cover daily swings.