try this - thanks to e_dub at covad.direct forum

open your command prompt and type: telnet 192.168.1.1

the password should be: 1234

you will see a list of menus, type 24 and hit enter

another list of menus will appear, type 8 and hit enter

you see a flashing cursor at the bottom of the screen;

here you will enter: wan adsl opencmd gdmt

hit enter. (once you hit enter your modem will lose sync because of the change. it will regain sync.)

you will be taken back to the flashing cursor. type exit to back out, your now done. just exit out of all the menu thus exiting telnet.