first download and install these 5 links below, one by one
after installing the Debian files,
open application > accessories > terminal
and write this command and hit enter
> sudo gedit /etc/wvdial.conf
the gedit text pad will be open, in that pad write the blow lines and save that
Modem = /dev/ttyUSB0
Baud = 230400
Phone = #777
Init1 = ATZ
Stupid Mode = 1
Dial Command = ATDT
PPPD Options = lock noauth refuse-eap refuse-chap refuse-mschap
>(in user name and password write phone no, with code , erase starting zero in code.
that is, if no 0809988777 then write it as 809988777)
now the configuration is over
write this blow command in terminal to connect Internet.
sudo wvdial bsnl
after the writing command it shows IP and DNS addresses.
now its connected
importent:- dont quit terminal during net connection
press ctrl+c to disconnect....