Incidentally, altering the mtu is unlikely to help (your isp will advise optimum setting) but if you are not on AOL then 1500 is fine. Also the BT business hubs I have found to be good on my line (51db attenuation) holding on to below 3db snr. You can pick them up cheap on ebay and then unlock them (single ssid version much prefered). Different routers report differing attenuations, BT hub says 51 db for me, dlink said 55 db.+ For comparison, I get between 3800 and 4300 -ish download syncs at 6db snr but with the odd overnight retrains.