Once you've plugged in your modem and know which serial port it's on you're ready to try using it. The protocol on the telephone line will be PPP (Point-to-Point Protocol), but PPP often gets set up without you needing to know much about it. If you already have an account with an ISP to connect to the Internet, you could try using a program like "wvdial" to connect to the Internet.
As an alternative to taking one big step using PPP to connect to the Internet, you could do a two step process: First just test out your modem without using PPP (using Minicom or Kermit). Then if your modem works OK, use "wvdial" or another ppp dialer to connect to the Internet. A different strategy is to first try a ppp dialer and then if that doesn't work out, fallback to Minicom or Kermit to see if your modem works OK. Knowing how to use either Minicom or Kermit is handy for dialing out to other modems directly without going thru the Internet. If you are going to use Minicom or Kermit you must find a phone number to dial that will accept phone calls from a computer (without using PPP). Perhaps a local library has such a phone number for its 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 this 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. Internet dialing programs (using PPP) include wvdial, pppconfig (Debian), kppp (KDE), and for Gnome: gnome-ppp or "modem lights". Non-internet dialing programs include: minicom, seyon (X Window), and kermit. See section Communications Programs about some communications programs. Three examples are presented next: Dialing Out with wvdial Dialing Out with Minicom and Dialing Out with Kermit
Wvdial is a program with not only dials out, but starts PPP and logs you in to an ISP where you get to the Internet. Wvdial may be configured during the installation process or by using the program "wvdialconf". See the man pages for both "wvdialconf" and "wvdial". However, before using wvdial you must do two other tasks not covered by the wvdial documentation:
Minicom comes with most Linux distributions. To configure it you should be the root user. As root, type "minicom -s" to configure. This will take you directly to the configuration (set-up) menus. This allows you to use the configuration immediately. If you just type "minicom" and then configure, you'll need to leave and restart minicom for the configuration to take effect. Within minicom 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).
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. Unless you've used the -s option when you called minicom, you'll need to exit minicom and start it again so it can now find the serial port and 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, try typing ATQ0 V1 EI and see if you get OK. If you still don't get OK, something is wrong and there is no point of trying to dial. Why you might need to type: ATQ0 V1 E1 is because a modem can be get into a state where is can't display OK and this should get it out of that state.
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.
You can find the latest version of
http://www.columbia.edu/kermit/. For example, say your
modem was on
ttyS4, 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/ttyS4 C-Kermit>set carrier-watch off C-Kermit>set speed 115200 /dev/ttyS4, 115200 bps C-Kermit>c Connecting to /dev/ttyS4, 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
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/ttyS4 ; Select communication device C-Kermit>set speed 115200 ; Set the dialing speed C-Kermit>dial 7654321 ; Dial Number: 7654321 Device=/dev/ttyS4, modem=usr, speed=115200 Call completed.<BEEP> Connecting to /dev/ttyS4, 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. Welcome to ... (a welcome message, etc.) login:
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Generated: 2007-01-26 17:58:20