@JohnJ
Hi John,
reading through your previous posts, apart from the difficulties of a longer line, I tend to suspect that part of the problem is that you haven't realised how the BT exchange DLM works when things are not perfect.
If you have a dropped connection from time to time and if the error rate is a bit on the high side, then it only takes a few modem/router reboots/resyncs for DLM to say - ah problem with this line, up the Target SNRM to try and stabilise it. And of course if disconnects continue - even if it's reboots, it will up it again and pretty rapidly. The exchange cannot tell the difference between a dropped connection and a reboot you've instigated.
The way to try and get a stable connection is to go for the lowest sync in the band for the profile you know you can hang onto for most of the time. This is of course on the assumption that you do not have any line or other faults, your internal wiring is optimised, bell wire issue dealt with, etc.
Eg. if you believe you can hang onto a 4000 profile, then the sync speed to aim at is 4544 or just above, not as high as 5088 or near.
The trick is to discover what Target SNRM you need to achieve that, & worse it will vary depending on what the background noise levels are like (it's still better to sync in the day by the way) - also bearing in mind the limitations of DMT Target setting , & I believe a similar approach with Netgears with their own firmware or with DGTeam.
The technique I use with DMT after a powerdown is to have the line unplugged, powerup the modem/router, set the Target, press the button then plug the line in - works a treat as long as you get the Target right! The other part of this trick is to err on the cautious side so the sync might end up low rather than high. Now that might sound a bit contrary to what one wants, but the reason is as long as the low sync is not maintained for more than supposedly 75 minutes (but I never allow it to go more than a few minutes) or you get a low sync more than twice in that same interval it won't affect the profile. So if it syncs too low, adjust the target and reboot. If you have to do it a second time then you got to be sure to try and go a bit high or risk losing the profile. If you unfortunately go too high, you risk leaving it when things get noisy and get a drop, or turn off and try again tomorrow so to speak. If you go too high in the first place and have to try and bring it down there is a danger the DLM will think you have a line problem. I either risk leaving it and try again the next day if it holds, or switch off before then and try again later.
The one rule I always say for all this and if you are testing and have to swap things about is ALWAYS powerdown the modem/router and wait several minutes before unplugging the line, filter or master - anything that disconnects it from the line. That way, DLM hopefully sees the powerdown and doesn''t think you have a line drop problem, and don't do it more than 5 times in an hour, then leave it for the rest of the day (gives a margin of safety - touch wood). The 2nd rule is to do this when noise levels are stable, which for most people will be during the day, and at this time of year, well after sunrise & well before sunset (at least 1&1/2hrs).
Note that at this time of year noise conditions can be more unstable during the day. If you run a program like RouterStats, you can see what your Noise Margins (& hence noise levels) are doing.
I have to say that although these techniques work nearly all the time I have had the odd fail, you just have to live with it. Once you get the sync speed you want, leave it alone, do not resync or switch off, especially if you are in a training period. If DLM drops the sync in a training period, then try to get back to the optimum sync, but do not try it more than twice (not 5 times) in a day. Then leave it alone.
Just a few points on things said above, PN should be able to tell you whether you line is in a new training period or not. You cannot conclude that a training period is not involved just because the SNRM went straight down to 6dB no steps, that's precisely what it should do when manually set and also if a new training period is instigated - training starts with a 6dB Target.
Also, don't reboot unnecessarily, to gateway hop for example you only need drop the ppp session which is usually done by using the Connect/Disconnect button in the modem/router interface BUT there are some modem/routers where this still causes a resync, so be careful. Likewise profile changes should not need a reboot or a drop of ppp session, but if for some reason it doesn't get picked up then leave it until noise conditions are stable if a reboot is involved.
as MyBroadbandSpeed reports my download speed as 3398 kbps.
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