Nearly every ISDN adaptor device (network adapter or external ISDN modem) is
delivered with an application programming interface called CAPI (Common ISDN API, see
www.capi.org). Unfortunately these device drivers
are plattform specific shared libraries, e.g.
CAPI2032.DLL for Win32.
Java applications cannot access these libraries directly, so there must be a "bridge" in form of a platform specific native library which is conform to the Java Native Interface (JNI) and loads the CAPI library itself.
This project has just been started and the web pages are not ready. For more information, please look at the SourceForge page http://sourceforge.net/projects/jcapi or at my (German) web page: http://www.graefe.gmxhome.de/projects.htm