Configuring PPP on Debian GNU/Linux is straightforward once you have all the information you’ll need. Debian makes things even easier with its simple configuration tools.
Before you start, be sure you have all the information provided by your ISP. This might include:
Next, you’ll want to investigate your hardware setup: whether your modem works with GNU/Linux and which serial port it’s connected to.
A simple rule determines whether your modem will work. If it’s a “winmodem” or “host-based modem,” it won’t work. These modems are cheap because they have very little functionality, and they require the computer to make up for their shortcomings. Unfortunately, this means they are complex to program, and manufacturers generally do not make the specifications available for developers.
If you have a modem with its own on-board circuitry or an external modem, you should have no trouble at all.
On GNU/Linux systems, the serial ports are referred to as /dev/ttyS0, /dev/ttyS1, and so on. Your modem is almost certainly connected to either port 0 or port 1, equivalent to COM1: and COM2: under Windows. If you don’t know which your modem is connected to, run the program wvdialconf to try to detect it (see below); otherwise, just try both and see which works.
If you want to talk to your modem or dial your ISP without using PPP, you can use the minicom program. You may need to install the minicom package to make the program available.