georgesmh wroteOkay thanks for the info. Yes I already tried DMT but I haven't found any version that supports my router (Technicolor TG582n). RouterStats supports it directly.
There is also OrbMT.
http://orbmu2k.de/tools/orbmt-modem-tool-sidebar-gadget
From my experience, DMT provides the most stats, followed by OrbMT, then RouterStats. If your router allows you to telnet to it, you might be able to figure out other commands that can give you some more stats or configuration options. When you telnet try "?" or "help", to get a list of available commands. You can also try "echo bin/*" since most linux builds on routers don't support "dir" and "ls" commands. (Caution with what you do at the command line)
As andrew55 explained, tweaking the SNR margin isn't really for us in this country. But, what you're tweaking is the minimum (target) SNR margin that your modem will accept to connect at. Usually this value is set in the firmware between 6-9db. If one is having too much disconnections because of sudden burst of noise, they can increase the target (and decrease their sync speed). Or on the other hand, decrease the target, sync at higher speeds (ISP has to allow it), and risk an unstable connection, but if the lines are good (ie not in Lebanon) you might be able to get away with it.