Every image I've seen on this thread shows ADSL2+ selected implying this is what everybody uses when they adjust the SNM.

I'm surprised if you are all on ADSL2+ or is this the setting you should select whatever your connection.

It doesn't matter about that setting, the router will select the correct modulation regardless.

How long have you been on MAXDSL? Only a short time? 109 resyncs in 5 hours is a LOT, but if your target SNR margin in the DSLAM is set to 6db and you have such high attenuation, it's not unexpected to see so many resyncs. The BT DLM (Digital Line Managment) system should pick up on this eventually and raise your Target SNR margin by 3db until the line becomes more stable.

The gaps you talk about in the graph are normal, it's just the router masking out unusable, high frequency tones/carriers.

DLM might also turn Interleaving on for you anyway, if it decides it's needed.

You could try unplugging the Sky box from the phone socket and see if that makes a difference, dunno, don't have Sky myself.

looked for that app earlier but couldnt find it via google, whats the url thanks

what I have noticed and dicussed in another thread is that my snr doesnt move up and down progressively, it has sudden drops mostly after around 120 tone upwards.

the drops vary but generally are big, and almost all the snr to the right of 150 on the graph. +8db went down to -7 in an instant in one of the drops which caused a desynch.

Now bt have raised my target snr and not had a desynch yet but obviously lost speed and still getting these drops which I think are putting me close to a desynch.

sky made no diff.

the BT system seems to have raised my target snr now after a LOT of desynchs.

can I ask you tho, in your experience is it normal for large snr drops to happen at a split second?

all my screenshots available here.

http://iroffer.us/adsl/chris/

I will be buying a shielded cable to see if it helps.

http://adslm.dohrenburg.net/
Google only works if you search for adslmonitor - no gaps

If your line is subjected to some kind of impulse noise, then yeah, sudden drops in SNR margin can happen, high frequencies will be affected more than low ones. There's loads of things that influence adsl signals, you might have some local source of interference...keep your router as far away from the pc and monitor as possible or any other electronic equipment.

currently its in a different room to the pc and there is nothing electrical near it in a big room.

thanks

I only linked to this post because of the very nice snr graph.
My snr db per tone graph tops out at about 180 running with a nominal snr of 14db at 3000kbps from router and showing an snr of between 22db and 30db (between 130 and 180) and about 10db (between 30 and 125)
Is this caused by the line generally or is it something I can affect myself
Edit - Oh dear I think I see the problem. the snr as reported by the router has dropped to 11db but snr reported by dmt in the 136 - 180 band is down as low as 3db and is mostly down below 8db

Edited by deleted (Mon 26-Jun-06 22:51:11)