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[MJDalgleish]

Hi b4dger,

I'm currently using the Speedtouch 580, although I have gotten the same results when I tried the Netgear products.

The line syncs at 3 db and 7,000 kbps with the Speedtouch, when the modem re-boots and apparently the line allows it.  I have confirmed with my supplier I am on MAX.  Then, when the noise hits, it drops to 2,000 kpbs, still on the same 3 db margin.  When the noise goes, the SN jumps up to 20 or so, with the sync staying at 2,000, and then during the day, jumps back and forth 3 db to 20 db as shown on the graph.

I've attached two graphs so you can see this in RouterStats.

The Speedtouch seems to go for 3 db, whilst the Netgear goes for 6 db target noise margin.

Mike

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[b4dger]

Hi - I wonder if the Speedtouch has had it's target SNR tweaked in the past?

I would try a factory reset and then check the SNR...

[MJDalgleish]

B4dger, thanks,

I thought when I installed the software upgrade to the SpeedTouch Modem/Router, that it would do that.  I followed your suggestion and it has booted up with 7 dB SNR and 5376 kilobits.  (The modem reports 32,000 FEC Downlink errors, I am not sure if this is normal or excessive.) I wonder if it might hold this configuration?  We'll see over the next 24 hours.  (I attach the good looking graphs from RouterStats).

By the way, if this improves things, I could try to tweak the modem to say 9 dB.  I cant see how to do this since neither versions 7 or 8 of the DMT tool seem to support the SpeedTouch 580.  (SoftTouch Software 4.3.x). Can you suggest what I should do if needed to tweak the SNR target to say 9 db?

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[rwm32]

The FEC count shows the corrected errors, so in general don't worry too much about it. If it goes seriously ballistic (into 100s of millions), I'd reboot the modem and forget about it, subject to what else the modem stats are showing.

The CRC error count shows uncorrected errors (i.e. where the data had to be re-sent) and is a better indicator of things to worry about if it does more than creep up by a handful an hour on average.  Also worth monitoring Loss of Framing and Loss of Signal in your stats page over a period of time.

I'm not familiar with the 580, but that 4.x.x.x firmware sounds rather old and may not do bitswapping very well if at all, which is pretty important in maintaining stability on lines like mine which get hit by AM frequency interference at night.  Anyone else know about this?

Hope this helps

rwm32

edit: corrected typos

[MJDalgleish]

Thanks to everyone for suggestions so far; sadly to no avail.  I am still experiencing SNR jumps at random intervals. (see June 6 12:07 above). Any suggestions/ideas would be appreciated!  Mike.