Austrian ISDN problem

hi there.

i try to realize an asterisk system with ISDN (nt) - but i can get no connection in or out…

asterisk version: Asterisk 1.4.18
linux: debian etch (Linux aster 2.6.18-6-k7 #1 SMP Sun Feb 10 22:16:15 UTC 2008 i686 GNU/Linux)

please remember: i am from austrian, we have strange ISDN …

maybe someone knows this problem and the solution?