Linux configure modem to connect to the Internet using a PPP dialup account

Q. I want to configure modem to dial out and connect to the Internet. Since I don't have good display card, I am not using the X window system. How do I configure (external) modem to connect to the Internet using a PPP dialup account under Debian Linux?
A. It is true that dialup modems have become almost obsolete due to broadband Internet connections, there are still situations where dialup access can prove useful :)
Under Linux you can dial out using program called wvdial. It is a PPP dialer with built-in intelligence. It dials a modem and starts PPP in order to connect to the Internet. The connection started with wvdial can be dropped by switching back to the terminal from where it was started and pressing ctrl-C.
The default configuration file is: /etc/wvdial.conf.

Installation

Since you are using Debian Linux, use apt-get (assuming that CDROM is your source):
# apt-get install wvdial
Other Linux distribution users can download wvdial from Internet or install from your distribution CD/DVD-ROM disk.

Configuration

First, make sure modem is installed and type the following command to configure the modem:
# wvdialconf /etc/wvdial.conf
Once modem is detected you need to edit /etc/wvdial.conf configuration file to specify the PPP username, password and dial out phone number.
For example:
[Dialer Defaults]
Modem = /dev/ttyS1
Baud = 115200
Init1 = ATZ
Phone = 172226
Username = Your-USERNAME
Password = Your-PASSWORD
Save and close the file.
To connect to internet type command:
# wvdial
To disconnect, switch back to the terminal from where it was started and pressing CTRL+C.