Dear Sirs, dear Madams I've programmed an utility called kisdnmonitor, it tracks the calls you make/ receive. It's for KDE as the name suggests. There's a server as well, it's called isdnserver. You can get more infos on both on: http://www.elogix.ch/linux_en.html Now I would like to add telephony support to the programs, so that you can use the computer as a "deluxe" isdn phone. So far I've figured out that you can dial through the modem emulation /dev/ttyIx. You just properly configure the device and then with the following Hayes codes: ATS18=1 ATS14=4 ATD<the phone number> you can start a call. Everything is ok so far, the problem is that, obviously, no sound will automagically come out from the speakers and nothing that is brabbled through the mic will go to the other side. Basically, what I want to do, is to stream the sound from the isdncard to the speakers and from the mic to the isdncard. Vbox (a voice call programm) is able to save samples from the isdncard's input. I should mention as well that years ago, I had a program that came with the isdncard (for windoze) called RVScom that had the same functionality, and it worked (in walkie talkie mode, I guess that my isdncard isn't full duplex capable). Since 8 bits suffice, the processor load shouldn't be extreme. Has anyone an idea? Any help would be greatly appreciated. Thank you in advance Respectfully submitted George