New HOWTO: Modem-HOWTO - page 6

Table of Contents

  5.  Configuring Overview

  If you want to use a modem only for MS Windows/Dos, then you can just
  install almost any modem and it will work OK.  With a Linux PC it's
  not always this easy unless you use an external modem.  All external
  modems should work OK (even if they are labeled "Plug and Play")  But
  most new internal modems are Plug-and-Play (PnP) and have PnP serial
  ports.  In some cases (depending both on the modem and your version of
  Linux) The PnP configuring is built into the serial driver so you
  don't need to do anything.  If it's an ISA modem you may need to use
  the Linux "isapnp" program to configure it (but this is planned to be
  built into future drivers ??).  See the Plug-and-Play-HOWTO and the
  isapnp docs for more information.

  Since each modem has an associated serial port and the port has both
  hardware and software, there are four parts to configuring a modem:


  �  Configure the serial port PnP hardware: Done by PnP methods

  �  Configure the serial port driver (low-level): Done by "setserial"

  �  Configure the serial port driver (high-level): Done by the
     communication program (stty-like)

  �  Configure the modem itself: Done by the communication program

  Communication programs include aminicom, seyon, or wvdial (for PPP)
  and mgetty) for dial-in.  Such communication programs require that you
  configure them although the default configuration they come with may
  only need a little tweaking.

  Unfortunately the communication program doesn't do the low-level PnP
  configuring of the serial port: setting its IO address and IRQ in both
  the hardware and the driver.  If you are lucky, this will happen
  automatically when you boot Linux.  Setting these in the hardware was
  formerly done by jumpers but today it's done by "Plug-and-Play"
  software.

  But there's a serious problem: Linux (as of early 2001) is not a true
  Plug-and-Play operating system but the latest serial drivers handle
  Plug-and-Play for some serial posts (built-into internal modems).   In
  other case you may need to use Plug-and-Play tools to set up the
  configuration although they are not always very user friendly.  This
  may create a difficult problem for you.  The next section will go into
  this in much more detail.