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 <enter> 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

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.<BEEP>
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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