12.4. Internal modems
An internal modem is basically an external modem and serial
port mounted upon a PC bus card. These are
cheaper than external modems as they do not require a power supply
or a chassis.
Internal modems work fine for remote serial console
applications. They are especially attractive for computers at
co-location sites, as those sites charge according to space and
power consumption.
Check that your internal modem preserves its setting across a
power cycle.
Ensure that the interrupt line and port address space used by
the internal modem's serial port do not conflict with that used by
any other pre-existing serial ports. Alternatively, ensure that
the internal serial port can be disabled, freeing its interrupt
line and port address space for use by the internal modem.
Be careful not to confuse an internal modem with a WinModem.
An internal modem does not need a special device driver, but
appears to Linux as a
stardard serial port.