Setting Up the Modem Software

Table 1-2 provides an overview of the major tasks for each of the three usage modes. An "x" in the table cell denotes the task is performed.

Overview of Modem Software Setup

Task	Dial-in Only	Dial-out Only	Dial-in/ Dial-out
Turn off the port in /etc/inittab	x	x	x
Execute telinit q to reinitialize the port	x	x	x
Run fix-modem configuration script	x	x	x
Edit Devices file		x	x
Chown device to uucp		x	x
Update action field in /etc/inittab	x		x

Modem Software Setup, All Modes

1. Log in as root.

2. Edit /etc/inittab to turn off the port you will be using for your modem so you can configure it correctly.

   Find the line for the port. The line begins with tportnumber, where portnumber is the number of a serial port. For example, if you connected your modem to port 2, look for a line similar to the following:

   t2:23:respawn:/etc/getty -N ttyd2 co_9600 #port 2

   Change respawn to off. This tells the system not to restart the /etc/getty program when it exits. If it is already off, continue to the next step. The line should look like this when you are finished:

   t2:23:off:/etc/getty -N ttyd2 co_9600 #port 2

3. Write and exit the /etc/inittab file.

4. Inform init about the change to inittab with the following command:

   telinit q

5. Run the modem configuration script for your modem type (see Table 1-1). Select the appropriate argument for its usage mode from Table 1-3 for the port you are configuring.

   Determining the Usage Mode for Modem Configuration

   Dial-in	Dial-out	Dial-in/Dial-out
   -i	-o	-io

   Note: Be sure to view the entire configuration script for information and command arguments specific to your modem type before running the script.

   For example, if you want to configure a US Robotics Sportster modem for dial-in/dial-out, connected to port 2, use the fix-usr command and specify a dial-in/dial-out argument (-io) and the port number to which the modem is connected. For example, enter the command:

   /etc/uucp/fix-usr -io 2

   You can also specify the optional modem model type and the modem speed, using the command:

   /etc/uucp/fix-usr -io -m SPORT -s 38400 2

   As another example, to configure a Telebit modem for dial-in only mode, use the fix-telebit command and specify a dial-in modem (-i), the model of the modem (tb+, t1000, t1600, t2500) and its speed, and the port number to which the modem is connected.

   In this example, if a T2500 modem is connected to port 2 at 19,200 baud, dial-in only, enter the following command:

   /etc/uucp/fix-telebit -i -m t2500 -s 19200 2

• If you are configuring a dial-out modem, continue with the section, "Dial-out Mode".

• If you are configuring a dial-in modem, continue with the section, "Dial-in Mode".

• If you are configuring a dial-in/dial-out modem, continue with the section, "Dial-out Mode", followed by "Dial-in Mode".

Dial-out Mode

You turn on dial-out modem software by editing the /etc/uucp/Devices file. You also have to change ownership of the port to uucp.

1. Edit the /etc/uucp/Devices file to specify the port to which the modem is connected and to set the correct baud rate for the modem. Also, add a "Direct" line for use in debugging problems. The lines have the following forms:

   ACU ttynportnumber null baud 212 x dialer
Direct ttydportnumber - baud direct

   • If your modem runs at 2400 baud or lower, the n field should be m.

   • If it runs faster than 2400 baud and supports hardware flow control, the n field should be f.

   • All other cases can use d.

     The value for portnumber is the number of the serial port to which the modem is connected. The baud variable is the baud rate at which you will run the modem. The dialer variable is the model tag, as listed in the first field of the /etc/uucp/Dialers file.

     Note: If your modem type is not listed in the Dialers file, you may want to obtain the most up-to-date version of the Dialers file. It is available online from Silicon Graphics with the ftp utility.

     For example, for a US Robotics modem connected to serial port 2 that can accept and send data at 38400 baud (using RTS/CTS hardware flow control), add the following lines to the Devices file:

     ACU ttyf2 null 38400 212 x usr
Direct ttyd2 - 38400 direct
Direct ttyf2 - 38400 direct

     For a Telebit modem connected to serial port 2 and running at 19200 baud, add the following lines:

     ACU ttyf2 null 19200 212 x telebit
Direct ttyd2 - 19200 direct
Direct ttyf2 - 19200 direct

     Save and exit the Devices file.

2. Change the ownership of the device files. For example, if you are using serial port 2, give the following command (substituting the appropriate tty device as determined above):

   chown uucp /dev/tty[dfm]2

• If you are configuring your modem for dial-in/dial-out mode, continue with the section "Dial-in Mode".

Dial-in Mode

Complete the configuration by editing the file /etc/inittab. Perform the following steps:

1. Edit the file /etc/inittab again so the system recognizes that the port is used for the modem (as opposed to a terminal). This editing also sets the interface speed on the port and enables user logins through the port.

   Find the line for the port to which the modem is connected. The line begins with tportnumber, where portnumber is the number of a serial port. For example, if you connected your modem to port 2, look for a line similar to the following:

   t2:23:off:/etc/getty -N ttyd2 co_9600 #port 2

   Make the following changes to this line:

   • Change off to respawn.

   • Change /etc/getty to /usr/lib/uucp/uugetty.

   • Add the dial-in -i option with the modem model argument. Pick the modem model variable from Table 1-4 (or check the /etc/uucp/Dialers file for additional variables):

     inittab Dial-in Options by Modem Type

     Modem Type	-i Argument
     Telebit T2500, T1600, QBlazer, T3000, and WorldBlazer	telebitin,conn
     ZyXEL U-1496	zyin,conn
     Intel 14.4ex	intelin,conn
     DSI 9624 models	dsiin,conn
     US Robotics (also called USR)	usrin,conn
     Hayes ACCURA (also called Hayes14)	hayesin,conn

   • Change ttyd2 to ttyf2.

   • Change co_9600 to dx_38400 (this is the serial port interface speed. It lets the modem answer and connect at 38400 and slower baud rates.) Do not set this value to a speed slower than your modem.

   • Change the comment at the end of the line to note that this port is now used for a modem; include its phone number for reference.

     For example, if you connected a US Robotics modem to serial port 2, and found a line similar to this line in /etc/inittab:

     t2:23:off:/etc/getty -N ttyd2 co_9600 #port 2

     You would change it to read:

     t2:23:respawn:/usr/lib/uucp/uugetty -Nt60 -iusrin,conn ttyf2 dx_38400 #Modem 555-2345

     If you are setting up a Telebit modem to serial port 2, and found a line similar to this one:

     t2:23:off:/etc/getty -N ttyd2 co_9600 #port 2

     You would change it to read:

     t2:23:respawn:/usr/lib/uucp/uugetty -Nt60 -itelebitin,conn ttyf2 dx_19200 #Modem 555-3456

2. Write and exit the /etc/inittab file.

3. Inform init about the change to /etc/inittab with the following command:

   telinit q

To dial out through the modem to verify the dial-out setup, continue with the section "Dialing Out to Another Modem."