asterisk users - Mar 2005 - Asterisk and call delivery to connected PABX

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

> 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.
Lots of ways to do it, but will be dependent on the type of facilities
available in the pabx, the number of simultanous calls you want to
support, etc.

A couple of examples...
1. Digium PRI-T1 card to a pabx PRI (23/30 channels available)
2. Digium TDM-fxo card to pabx analog line (4 channels)
3. Sipura spa3000 adapter to pabx analog line (1 channel)

You might want to dig through pages on the wiki at:
 http://www.voip-info.org/tiki-index.php?page=Asterisk
for lots of good references.