asterisk users - Jul 2003 - AVM C4 and external and internal ISDN bus and *

Hi,

I want to utilize the above card to achieve the following
* Attach two ISDN connections (4 channels) to the outside world
* Have two internal ISDN connections (4 channels) to the inside
* Have multiple SIP phones connected

Anyone out there having success in utilizing the C4s ISDN ports to 
provide an internal ISDN bus for ISDN phone equipment?

Any pointers are greatly appreciated.

rgds
pos