I'll try to shorten my story with IDM, 2.5 years ago I moved to a new apartment, I submitted a new subscription form with IDM few days before I move, it didn't take long and it arrived, at that time 1mbps was the minimum most common plan, few months later all ADSL carriers switched to 2mbps as minimum, I was stuck at 1mbps as many as other IDM users (friends and family), they started to get the 2mbps and I was stuck at 1mbps, I called support and they said they will request a SpeedTest on my line from Ogero, the result returned that my line can ONLY handle 1mbps!!! Frustrating!!! I dug into it and noticed a low values of SNR (Signal/Noise), I logged using Telnet to the modem (which was the default Technicolor TG582n) and changed the standard used to an older protocol with less max bandwidth (more on that
here), this affected the SNR and it was increased from around 9dB (download) to around 30dB, after that I requested a new SpeedTest on my line, it took Ogero 3 months to do it! But shortly before I get the answer I changed the ADSL modem to TP-Link TD-W8901N which without any Standard modification was reporting good SNR numbers, I received a call from IDM few days later with a good news, my line now supports up to 4mbps! =D
Currently I'm enjoying the 2mbps, I'll apply for a plan change to 4mbps soon