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Modem Configuration!

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Pinki Meggi
Frequent Advisor

Modem Configuration!


Im very new with Linux. Im working with RHES3 and im trying to install and test efax package. For that i have add a modem to my PC ( Lucent HV90P-T ). But i have no idea how to test if the modem is installed and configured. I have tried to find out about the configuration of modem and i have find this article at
" Hardware modems should require no special configuration to work. once inserted and detected by the system, they should be accessible by the standard device special files /dev/ttys[0-3]"
But i have no ideia how to know if it is accessible or not.

If anyone can help me, please, or indicate any documentation to guide me, please.

Thanks in advance

Best Regards

Valued Contributor

Re: Modem Configuration!

minicom utility is used to comunicated with serial devices, like modems .... so read link about maybe it will help you
Honored Contributor

Re: Modem Configuration!

Sadly, most internal modems these days are best known as "winmodems" or "controllerless modems". Instead of behaving like a standard serial port, they have a model-specific, undocumented hardware interface. Often a driver exists only for some versions of Microsoft Windows - hence the name "winmodems".

This is an effort to reduce the number and complexity of the modem components, and it pushes to the CPU most of the workload that used to be handled by the modem hardware.

However, there are still a few internal modems that are constructed in the old way, and are easily useable in Linux.

This sad state does not affect external modems: all external modems that connect to the computer through a serial port (aka COM port) should be useable with Linux without extra trouble.

If a modem is connected through a USB port, it should work if it uses the CDC ACM specification of the USB standards family. In this case, the device name will probably be /dev/usb/ttyACM0 or /dev/ttyACM0.
To my knowledge, most of the USB modems use this specification.

To list all serial ports and (non-winmodem) internal modems, use this command (note capital S in "ttyS"):
setserial -g /dev/ttyS*

It will produce a listing like this:
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4
/dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3

If your computer has any serial ports, they are very likely to be /dev/ttyS0 and /dev/ttyS1. Any others could be the internal modem.

Pay attention to the "UART:" part. If it says "UART: unknown", the port might be a "ghost": since serial ports have existed almost unchanged since the first IBM PC/AT, there is no 100% sure modern auto-detection method for them.
The older Linux distributions may produce a long list of non-functional ttyS* devices: the tidying up of the list is a relatively recent development.

If this does not help, your modem might be a winmodem - or it might just need a special command or two to make it work.

Use the command "lspci -v" to get a listing of all PCI cards in your computer. The list will usually include the devices integrated on your motherboard, too.

Try to locate your modem in that listing and post here the part that refers to your modem. The technical information in that list will help in determining whether your modem is usable in Linux or not.
Pinki Meggi
Frequent Advisor

Re: Modem Configuration!


Thanks for replies and attention and thanks for the explanation about modems, it helps me alot.

Well, i have done the command "lspci -v" and when trying to locate my modem in the list i have find out the following:

00:07.0 Communication Controller: Agere Systems ( Former Lucent Microelectronics) 56K WinModem (rev 01)
Subsystem: Actiontec Electronics Inc: Unknown device 0440
Flags: bus master, medium devsel, latency 0, IRQ 11
Memory at cc102000 c32-bit, non I/O ports at d800[size 8]
I/O ports at dc00 [size 256]
Capabilities: [f8] Power Managment version 2

Thts the part, i suppose, taht refers to my modem.

Well, now how do i now if it is usable in Linux?

Best Regards


Honored Contributor

Re: Modem Configuration!

Sorry - looks like you have a winmodem. It even claims itself as such: "Communication Controller: Agere Systems ( Former Lucent Microelectronics) 56K WinModem" is a big clue.
Generally, a "real" modem would not have the "Memory at ..." line at all, and the "IO ports at ..." line would be different: the address could be anything, but the size of the IO port group should be more like 8 or 16, not 256 as in your case.

However, there is some hope: there is a special driver for *some* (not all) winmodems manufactured by Lucent/Agere. It *may* work with your modem. It is available here:

Since there doesn't seem to be pre-compiled packages for RedHat ES3 (only for the obsoleted RedHat 9), you would have to compile the driver from source code. As you say you're new with Linux, I'm afraid this would be a very big challenge to you.

I would recommend trying to trade your modem in for an external one. It is certainly the easiest and most reliable way to solve this problem.

If you're willing to try the ltmodem driver package, please try to have someone who's more familiar with Linux physically present when doing the installation, even though the ltmodem package has very good instructions. If something goes wrong, a great deal of techical details is needed in the troubleshooting: trying to debug this kind of thing through a Web forum will require heroic amounts of patience.