how to configure 220bx1 on MTNL connection(not getting "link" light permanently on)


I am using beetel 220bx1 adsl2 modem.Earlier i was using this modem with airtel broadband connection. now i have shifted to mtnl broadband connection. But the MTNL guys refuse to help as I am not buying their modem. kindly help me to connect this modem with MTNL broadband connection. The "line" light is supposed to go yellow "permanently" but it goes yellow only for a very less amount of time and then goes blank intermittently. The MTNL line-man has checked it with his modem and the "line" light is active permanently for his modem. I don't know how to configure it for MTNL. Please help.Thanks in advance.aman.taneja.2008 (at) gmail9717417410