Modems for a Linux PC 2.1 External vs. Internal A modem for a PC may be either internal or external. Internal modems are less expensive, are less likely to to suffer data loss due to buffer overrun, usually use less electricity, and use up no space on your desk. External modems are much easier to install and require less configuration. They have lights which may give you a clue as to what is happening and aid in troubleshooting. The fact that the serial port and modem can be physically separated also aids in troubleshooting.
External modems are easy to move to another computer.
Some of the modems which will work only under MS Windows are, unfortunately, not labeled as such. If you buy a new one, make sure that you can return it for a refund if it will not work under Linux. Each of the above has shortcomings. If you want the PnP BIOS to do the configuring, all you need to do is to make sure that it knows you don't have a PnP operating system. But it may not do it correctly.