I recently procured an ADSL modem for use with my BSNL broadband connection, and had some anxious moments trying to configure some configuration parameters to make it connect successfully to the Internet. So, thought of sharing like parameters here. Well, here they are:
|ISP/Connection Type||Bridge Mode|
Of these, the most important setting probably is for the VPI/VCI and Connection Type. After googling, I found suggestions for specifying PPPoA/PPPoE as the value for this parameter, but take care that this value is for MTNL, and not BSNL. For BSNL, Connection Type/ISP has to be Bridge Mode.
For reference, I am attaching 2 images below, one for Beetle, and the other for D-Link modems that should also provide some help.