Looking for someone with knowledge of Apropos IVR integration

[whiteta]

We have a site that is using an older NEC 2000 pbx, which is connected to an Apropos/Syntellect IVR server using analog ports. We are in the midst of converting the site to an Avaya G450 gateway registered to our main Avaya core, using VoIP. I have to determine how we go about integrating the Apropos IVR with Avaya. My guess is that its doing some sort of in band DTMF signalling with the NEC, which I can do with Avaya using the converse-on vector command. I can find no documentation on how the integration is currently setup, like dial strings, etc. Searching on line only finds a way to integrate Avaya using line side T1. Anybody have any insight or know how on this subject? If all else fails, I plan to connect the NEC to my gateway with a cross over cabled ISDN PRI tie line DS1 and use the NEC as the integration piece only until we retire the old IVR. That way I can send digits across the TIE line and the NEC can process the call to the IVR based on the digits I send. For example, toll free call comes into the NEC now and pulses in "521", which tells the IVR what app to run.