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New HOWTO: Modem-HOWTO - page 12

Table of Contents

  • April 12, 2001
  11.  Trying Out Your Modem (Dialing Out)

  11.1.  Are You Ready to Dial Out ?

  Once you've plugged in your modem and know which serial port it's on
  you're ready to try using it.  Before you try to get the Internet on
  it or have people call in to you, you could first try something
  simpler like dialing out to some number to see if your modem is
  working OK.  Find a phone number that is connected to a modem.  If you
  don't know what number to call, find out if a local library has a
  phone number for an on-line catalog.

  Then make sure you are ready to phone.  Do you know what serial port
  (such as ttyS2) your modem is on?  You should have found this out when
  you io-irq configured your serial ports.  Have you decided what speed
  you are going to use for this port?  See ``Speed Table'' for a quick
  selection or ``What Speed Should I Use with My Modem'' for more
  details.  If you have no clue of what speed to set, try setting it a
  few times faster than the advertised speed of your modem.  Also
  remember that if you see a menu where an option is "hardware flow
  control" and/or "RTS/CTS" or the like, select it.  Is a live telephone
  cable plugged in to your modem?  You may want to connect the cable to
  a real telephone to make sure that it can produce a dial tone.

  Now you need to select a communication (dialing) program to use to
  dial out.  Dialing programs include: minicom, seyon (X-windows), and
  kermit.  See section ``Communications Programs'' about some
  communications programs.  Two examples are presented next: ``Dialing
  Out with Minicom'' and ``Dialing Out with Kermit''



  11.2.  Dialing Out with Minicom

  Minicom comes with most Linux distributions.  To configure it you
  should be the root user.  Type "minicom -s" to configure.  This will
  take you directly to the configuration (set-up) menus.  Alternatively
  you could just run "minicom" and then type ^A to see the bottom status
  line.  This shows to type ^A Z for help (you've already typed the ^A
  so just type z).  From the help menu go to the Configuration menu.

  Most of the options don't need to be set for just simply dialing out.
  To configure you have to supply a few basic items: the name of the
  serial port your modem is on such as /dev/ttyS2 and the speed such as
  115200.  These are set at the serial port menu.  Go to it and set
  them.  Also (if possible) set hardware flow control (RTS/CTS).  Then
  save them.  When typing in the speed, you should also see something
  like "8N1" which you should leave alone.  It means: 8-bit bytes, No
  parity, 1 stop-bit appended to each byte.  If you can't find the speed
  you want, a lower speed will always work for a test.   Exit (hit
  return) when done and save the configuration as default (dfl) using
  the menu.  You may want to exit minicom and start it again so it can
  now find the serial port and initialize the modem, or you could go to
  help and tell minicom to initialize the modem.
  Now you are ready to dial.  But first at the main screen you get after
  you first type "minicom" make sure there's a modem there by typing AT
  and then hit the  key.  It should display OK.  If it doesn't
  something is wrong and there is no point of trying to dial.

  If you got the "OK" go back to help and select the dialing directory.
  You may edit it and type in a phone number, etc. into the directory
  and then select "dial" to dial it.  Alternatively, you may just dial
  manually (by selecting "manual" and then type the number at the
  keyboard).  If it doesn't work, carefully note any error messages and
  try to figure out what went wrong.


  11.3.  Dialing Out with Kermit

  You can find the latest version of kermit at
  http://www.columbia.edu/kermit/.  For example, say your modem was on
  ttyS3, and its speed was 115200 bps.  You would do the following:


       linux# kermit
       C-Kermit 6.0.192, 6 Sep 96, for Linux
        Copyright (C) 1985, 1996,
         Trustees of Columbia University in the City of New York.
       Default file-transfer mode is BINARY
       Type ? or HELP for help.
       C-Kermit>set line /dev/ttyS3
       C-Kermit>set carrier-watch off
       C-Kermit>set speed 115200
       /dev/ttyS3, 115200 bps
       C-Kermit>c
       Connecting to /dev/ttyS3, speed 115200.
       The escape character is Ctrl-\ (ASCII 28, FS)
       Type the escape character followed by C to get back,
       or followed by ? to see other options.
       ATE1Q0V1                           ; you type this and then the Enter key
       OK                                 ; modem should respond with this



  If your modem responds to AT commands, you can assume your modem is
  working correctly on the Linux side.  Now try calling another modem by
  typing:


       ATDT7654321



  where 7654321 is a phone number.  Use ATDP instead of ATDT if you have
  a pulse line.  If the call goes through, your modem is working.

  To get back to the kermit prompt, hold down the Ctrl key, press the
  backslash key, then let go of the Ctrl key, then press the C key:


       Ctrl-\-C
       (Back at linux)
       C-Kermit>quit
       linux#



  This was just a test using the primitive "by-hand" dialing method.
  The normal method is to let kermit do the dialing for you with its
  built-in modem database and automatic dialing features, for example
  using a US Robotics (USR) modem:


       linux# kermit
       C-Kermit 6.0.192, 6 Sep 1997, for Linux
        Copyright (C) 1985, 1996,
         Trustees of Columbia University in the City of New York.
       Default file-transfer mode is BINARY
       Type ? or HELP for help
       C-Kermit>set modem type usr        ; Select modem type
       C-Kermit>set line /dev/ttyS3       ; Select communication device
       C-Kermit>set speed 115200          ; Set the dialing speed
       C-Kermit>dial 7654321              ; Dial
        Number: 7654321
        Device=/dev/ttyS3, modem=usr, speed=115200
        Call completed.
       Connecting to /dev/ttyS3, speed 115200
       The escape character is Ctrl-\ (ASCII 28, FS).
       Type the escape character followed by C to get back,
       or followed by ? to see other options.

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