Configuration of various types of dialup modems

Configuring the modem may or may not be a part of the installation procedure. Determining what sort of modem you have should be a part of the Pre-installation process. You’ll want to know up front if the modem in your computer is going to work in Linux.

First you have to determine what type of modem you have.

• If your modem is a hardware modem and is not plug and play, then you probably are not checking here, because you already are online.

You may have a hardware modem that is plug and play - PCI or ISA - most likely nowadays a PCI modem. The new modem that I got is a US Robotics Performance Pro (5610B). It was a little expensive ($70), but I was very happy to see Linux on the box and in the instructions. I was prepared to do the PCI Modem routine described below, but had no problem at all with it. So the first thing you should try is to make the link from the actual device to ‘/dev/modem’. This is a good idea, because most dialup programs use /dev/modem as the default device. On the command line do:

           cd /dev
           ln -s ttyS4 modem

If you have a PCI Modem you may need to run setserial.

• less /proc/pci (You will then see a list of all you PCI devices.)
• Example of output:

  Bus 0, device 17, function 0: Serial controller: Unknown vendor
  Unknown device (rev 1). Vendor id=12b9. Device id=1008. Medium devsel.
  IRQ 11. I/O at 0xcc00 [0xcc01].

• Note that the first I/O port is 0xcc00 and the IRQ is 11
• As root you need to run setserial. You may first need to create a link to one of the unused serial devices. Using the above example it would be:

        cd /dev
        ln -s ttyS3 modem
        setserial /dev/modem uart 16550A port 0xcc00 irq 11

• Naturally, you must use the port and irq that you found when you looked at /proc/pci and not those in this example!
• Then try to connect using /dev/modem where your connection program asks for the location of your modem. If this works, then you will want to place that setserial line into the init script (rc.local or similar) for your distro so that you don’t have to run this command every time you reboot Linux.

If your modem is not plug and play, then you just have to find out if it is on COM1(/dev/ttyS0) or COM2(/dev/ttyS1). You may even have a jumper on the modem that you can set for the port of your choice.

• Make the link to /dev/modem:

  cd /dev
  ln -s ttyS0 modem

• Run your configuration program for connecting and give it /dev/modem for the modem location. If you prefer not to make the link, you can simply give the connection program the actual device - like /dev/ttyS0.

• You may have one of a variety of winmodems which may or may not have a driver that works with Linux. There is a good chance that you can get a driver for it. I got a driver from Intel for my Intel 536ep which came on my latest computer. I decided to get a hardware modem anyway, because I could see that I’d have to replace the driver every time I upgraded the kernel. If you don’t want to get a hardware modem just now, check http://linmodems.org/ or http://start.at/modem. or even your modem manufacturer to see if you can get a Linux driver for it.
  • Other links for winmodem drivers:
    • Conexant Modems (HCF and HSF): http://www.linuxant.com/
    • Smart Link Modems: http://www.smlink.com/main/index.php
    • Lucent Modems: http://www.physcip.uni-stuttgart.de/heby/ltmodem/
    • PCTel Modems: http://linmodems.technion.ac.il/pctel-linux/
• To find out what modem you have try this:
  

lspci | grep -i modem

(Note: the vertical bar, referred to as a pipe symbol, is usually located above the Enter key.) On my notebook computer, this returns the following:

0000:00:09.1 Serial controller: Lucent Microelectronics LT WinModem

• You may want to use the ScanModem utility which is a bash script that runs in Linux to get information about your modem. You can find that at http://linmodems.technion.ac.il/#scanmodem. Download it and put it into a separate directory. Then:

        gunzip scanModem.gz
        bash scanModem

• A series of files will be produced that has a lot of information about your computer including your modem. If you are running Windows on your computer, you can hav a look at the Device Manager to see what the name of your modem is. You can do a search on the Internet to find out more information about it once you have the name.

Plug and Play ISA modems need yet another procedure. Take a look at: http://www.justlinux.com/nhf/Modems/ISA_PNP_Modems.html

True if they are serial, but maybe not true if they are USB. Check http://www.qbik.ch/usb/devices/showdevcat.php?id=14 before buying.

See Getting Online for information about how to get online once you have your modem working.

http://www.tuxmagazine.com/node/1000009: Of Modems and Winmodems by Marcel Gagné

http://65.70.147.202:8080/gromitkc/pci_list.html: PCI Modem listing from Linux/Modem Compatibility Knowledge

http://65.70.147.202:8080/gromitkc/winmodem.html#Database: This page has the links to other listings - USB, ISA, PCMCIA, External.

http://www.tldp.org/HOWTO/Modem-HOWTO-1.html: Modem HOWTO from the place where you find all the HOWTOs. Be sure to check http://tldp.org when you have a question. They just might have the answer.

From Jim via Howard Rosen in mailing list: http://mail.linuxbasics.org/pipermail/qna/2005-May/002459.html