For ISDN you need to access the installed CAPI driver. I made a CAPI Monitor for windows (32-bit) some years ago in C++. I used the Eicon SDK. There is also an SDK (or ADK) from AVM but I don't know if it is compatible with all available CAPI's. Heard from problems some time ago.
You can get the CAPI Monitor v1.07 from this page to try:
http://www.freewareguide.de/win9x/dfue1.shtml#dfue
Because I stopped development in November 2000 my own homepage is not available anymore.
You can get the CAPI Monitor v1.07 from this page to try:
http://www.freewareguide.de/win9x/dfue1.shtml#dfue
Because I stopped development in November 2000 my own homepage is not available anymore.