the default IP which router usually have are.
192.168.1.1
192.168.0.1
try these both if any of this work then write
username:admin
password:admin
to access the router config.
there u will see
Encapsulation: set to PPPOA or PPPOE...most of the times PPPOA works...
QOS TYPE : set it to UBR
Multiplexing:set it to VC
Virtual Circuit: 8 VCI
35 VPI its very important as Q-tel dsl works on it and no other..
and the last part
username:ur phone number for exapmle g4444444 OR s4444444
password:xxxxxx

I HOPE THIS HELPS