Ah, I think I see what you're trying to do..
Ok.. So if I understand it correctly:
You want a 24/30 port IVR system (utilizing the Brooktrout card) which you want to connect it to a PBX.
Asterisk itself can be used as an IVR system and can be used purely for VoIP out of the box with no hardware (using a VoIP provider to provide the lines).
The configuration would look much like:
PSTN <-> VoIP Provider <-> Internet <-> Router <-> Asterisk PBX/IVR
Your configuration would look more like:
PSTN <-> PBX <-> IVR
Ethernet wouldn't come into it except for the VoIP side. The RJ48C connectors are probably both T1/E1.
You could just buy an old PBX, you would be looking at something like an Avaya IP Office, 3com NBX or Samsung DCS (I think it has a PRI). Of those 3 only the Avaya and 3com have IP connectivity but I don't think they use SIP. I'm not sure about Windows, there is a Win32 port of asterisk available but I'm not up to date with where it is with it's hardware support. A google search for Asterisk Win32 should help on that one.
Hope that helps,
Paul
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