Internet using dialup modem in Command line

WvDial - A command-line pppd driver

# wvdialconf
# wvdialconf wvdial.conf
Once you have run wvdialconf, you need to edit the /etc/wvdial.conf file to enter the phone number to dial, and your username and password.
Open up /etc/wvdial.conf in your favorite text editor.
It should look something like this:
[Dialer Defaults]
Modem = /dev/ttyS1
Baud = 115200
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 S11=55 +FCLASS=0
Phone = 13125222
Username = shahbaz
Password = password
Remove the ';' and fill in the appropriate fields- phone number, login name and password.
Now you should be all set to run wvdial.

Run wvdial.
Assuming that you filled in your phone number, username, and password correctly, wvdial will now dial your ISP.
wvdial will not exit until the connection is terminated- you can do a Ctrl-C to terminate it.

# wvdial