[Asterisk-Users] Asterisk and call delivery to connected PABX

[XTRANET Technik]

Hello all!

I'm VERY new in using VoIP. I'm looking for any tip or trick to connect a 
physically PABX behind an Asterisk-System(or similar) via an SIP to Analog- 
or ISDN-Converter. The point is, I _need_ to deliver calls to extensions in 
the connected PABX directly (in ISDN-speech "DDI" (DirectDialIn)) without 
intervention of an operator. Is this technically possible, and if yes HOW?
Tips for Hardware-Converters (SIP->ISDN(EDSS1), SIP->Analog) are also 
appreciated.


Cheers,
  Peter