In the past few weeks I've been striving to get my modem to work. I am posting this via my linux box . What I need right now is to setup my machine so that I am able to send and receive faxes, make normal/voice phone calls via my linux box using a headset and record the phone conversations.

From the experience of the past few weeks I came to an understanding that external modems are the best choice. In my country (croatia) vd56sp external conexant pro-nets fax/voice/speakerphone/svd modem is available.

I would buy that modem if someone could confirm that I would be able to achieve the functionality that I need using it. I have also tried to find some software that would provide support for all that. Is there some linux software that could provide in one place all that funcionality? I am willing to setup anything and read all the documentation needed, I just need some pointers because I could not find too much on my own.

Currently I have an internal PCTel hsp56 micromodem that I could not get working and an external U.S. Robotics that (I think) does not have voice/speakerphone funcionality (I could not determine the exact model all there is on it is U.S. Robotics 56K FaxModem and these two id strings: 1MBGF49C[zero or letter O]BTU and 64-995630-02).

uname -a: Linux david 2.6.18 #1 SMP PREEMPT Mon Oct 2 16:59:00 CEST 2006 i686 GNU/Linux, Debian testing

lspci:
00:00.0 Host bridge: Advanced Micro Devices [AMD] AMD-760 [IGD4-1P] System Controller (rev 13)
00:01.0 PCI bridge: Advanced Micro Devices [AMD] AMD-760 [IGD4-1P] AGP Bridge
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev 40)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:07.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1a)
00:07.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1a)
00:07.4 SMBus: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev 40)
00:08.0 Multimedia audio controller: C-Media Electronics Inc CM8738 (rev 10)
00:09.0 USB Controller: ALi Corporation USB 1.1 Controller (rev 03)
00:09.1 USB Controller: ALi Corporation USB 1.1 Controller (rev 03)
00:09.2 USB Controller: ALi Corporation USB 1.1 Controller (rev 03)
00:09.3 USB Controller: ALi Corporation USB 2.0 Controller (rev 01)
00:11.0 Modem: PCTel Inc HSP56 MicroModem (rev 04)
01:05.0 VGA compatible controller: ATI Technologies Inc Rage 128 PF/PRO AGP 4x TMDS

Abit KG7 Raid, AMD Athlon XP 1600+ 512+256MB RAM, 15GB hard, 17" SyncMaster 755DFX, no Windows on the machine.

I have a headset with standard speaker+microphone plugs tested on my box via xmms (earphones) and audacity (microphone) and all works as expected.

In my experience, it's really hard to get a modem that works well with Linux, unless it's an external, Rockwell (Conexant) based Serial Modem. I gave up trying to find one here that worked, but I understand Zyxel are good.
Software: http://www.vocpsystem.com/index.php
It has excellent instructions, including details on getting the modems running on Linux, all the AT commands, etc. It uses vgetty as it's backend, which is now very old, but the only engine available, as far as I know.

Try this external serial port modem, I know it works on Mandriva Linux,I'm using it now, almost "plug and play"
U.S. Robotics USR5686E 56Kbps RS-232 (Serial Port) External Fax Modem

I've had good luck with all 3Com and U.S. Robotics internal PCI, hardware modems, not Winmodems(software based). The fastest 56K modem I've seen on Linux was an oddball U.S.Robotics PCI modem that I bought from Dan's. It consistantly ran at 67K. The hardware based internal 56K modems are getting difficult to obtain. You can contact Dan at Dans Discount Computer Parts Outlet on eBay to get used or sometimes new internal hardware modems by 3Com or U.S. Robotics. He knows the differences between the software winmodems and the hardware modems, the internal PCI modems are cheap ! The fax potion will need a Linux based fax program such as supplied by KDE. The above modem allows incoming telephone calls, don't know about outgoing calls.
Scott Nash

Have you tried the scanModem tool for your HSP (internal) modem?
This is a PCTel Modem ... According to the linmodem project, the driver has been released, but PCTel does not distribute it. You can get a copy from PCCHIPS, who puts one of PCTel's modems on their motherboard.